Excel sheet for java

import java.io.File;

import org.apache.poi.ss.usermodel.Cell;

import org.apache.poi.xssf.usermodel.XSSFRow;

import org.apache.poi.xssf.usermodel.XSSFSheet;

import org.apache.poi.xssf.usermodel.XSSFWorkbook;

import java.io.FileOutputStream;

import java.util.Map;

import java.util.Set;

import java.util.TreeMap;

public class WriteDataToExcel {

    public static void main(String[] args) throws Exception

    {

        XSSFWorkbook workbook = new XSSFWorkbook();

        XSSFSheet spreadsheet

            = workbook.createSheet(" Student Data ");

        XSSFRow row;

        Map<String, Object[]> studentData

            = new TreeMap<String, Object[]>();

        studentData.put(

            "1",

            new Object[] { "Roll No", "NAME", "Year" });

        studentData.put("2", new Object[] { "128", "Aditya",

                                            "2nd year" });

        studentData.put(

            "3",

            new Object[] { "129", "Narayana", "2nd year" });

        studentData.put("4", new Object[] { "130", "Mohan",

                                            "2nd year" });

        studentData.put("5", new Object[] { "131", "Radha",

                                            "2nd year" });

        studentData.put("6", new Object[] { "132", "Gopal",

                                            "2nd year" });

        Set<String> keyid = studentData.keySet();

        int rowid = 0;

        for (String key : keyid) {

            row = spreadsheet.createRow(rowid++);

            Object[] objectArr = studentData.get(key);

            int cellid = 0;

            for (Object obj : objectArr) {

                Cell cell = row.createCell(cellid++);

                cell.setCellValue((String)obj);

            }

        }

        FileOutputStream out = new FileOutputStream(

            new File("C:/savedexcel/GFGsheet.xlsx"));

        workbook.write(out);

        out.close();

    }

}

Рассказывает автор блога javarevisited.blogspot.ru


Из этой статьи вы сможете узнать о записи и чтении данных из Excel файлов в Java (будет рассмотрен как XLS, так и XLSX формат). Мы будем использовать библиотеку Apache POI и сосредоточимся на работе с типами String и Date, работа с последним происходит достаточно хитро. Напомню, что работу с числами мы уже рассмотрели в другой статье.

Библиотеку poi-XX.jar вы можете использовать для всех старых (xls, doc, ppt) файлов Microsoft Office, для новых (xlsx, docx, pptx) вам понадобится poi-ooxml-XX.jar. Очень важно понимать, что к чему относится, т.к. используемые классы тоже разные — для старых расширений это HSSFWorkbook, а для новых — XSSFWorkbook.

Подготовка: загрузка библиотек и зависимостей

Конечно, существует достаточно много открытых библиотек, которые позволяют работать с Excel файлами в Java, например, JXL, но мы будем использовать имеющую самый обширный API и самую популярную — Apache POI. Чтобы её использовать, вам нужно скачать jar файлы и добавить их через Eclipse вручную, или вы можете предоставить это Maven.

Во втором случае вам нужно просто добавить следующие две зависимости:

<dependencies>
    <dependency>
        <groupId>org.apache.poi</groupId>
        <artifactId>poi</artifactId>
        <version>3.12</version>
    </dependency>
    <dependency>
        <groupId>org.apache.poi</groupId>
        <artifactId>poi-ooxml</artifactId>
        <version>3.12</version>
    </dependency>
  </dependencies>

Самое удобное в Maven — что он загрузит не только указанные poi.jar и poi-ooxml.jar, но и все jar файлы, которые используются внутри, то есть xmlbeans-2.6.0.jar, stax-api-1.0.1.jar, poi-ooxml-schemas-3.12.jar и commons-codec-1.9.jar.

Если вы будете добавлять библиотеки вручную — не забудьте о вышеназванных файлах. Скачать всё можно отсюда. Помните — если вы загрузите только poi-XX.jar, то ваш код скомпилируется без ошибок, но потом упадёт с java.lang.NoClassDefFoundError: org/apache/xmlbeans/XmlObject, так как внутри будет вызываться xmlbeans.jar.

Запись

В этом примере мы запишем в xls файл следующие данные: в первую ячейку — строку с именем, а во вторую — дату рождения. Вот пошаговая инструкция:

  • Создаём объект HSSFWorkBook;
  • Создаём лист, используя на объекте, созданном в предыдущем шаге, createSheet();
  • Создаём на листе строку, используя createRow();
  • Создаём в строке ячейку — createCell();
  • Задаём значение ячейки через setCellValue();
  • Записываем workbook в File через FileOutputStream;
  • Закрываем workbook, вызывая close().

Для записи строк или чисел этого вполне достаточно, но чтобы записать дату, нам понадобится сделать ещё кое-что:

  • Создать DateFormat;
  • Создать CellStyle;
  • Записать DateFormat в CellStyle;
  • Записать CellStyle в ячейку;
  • Теперь в эту ячейку можно записать объект Date через всё тот же setCellValue;
  • Чтобы дата поместилась в ячейку, нам нужно добавить столбцу свойство автоматически менять размер: sheet.autoSizeColumn(1).

Всё вместе это будет выглядеть так:

@SuppressWarnings("deprecation")
    public static void writeIntoExcel(String file) throws FileNotFoundException, IOException{
        Workbook book = new HSSFWorkbook();
        Sheet sheet = book.createSheet("Birthdays");

        // Нумерация начинается с нуля
        Row row = sheet.createRow(0); 
        
        // Мы запишем имя и дату в два столбца
        // имя будет String, а дата рождения --- Date,
        // формата dd.mm.yyyy
        Cell name = row.createCell(0);
        name.setCellValue("John");
        
        Cell birthdate = row.createCell(1);
        
        DataFormat format = book.createDataFormat();
        CellStyle dateStyle = book.createCellStyle();
        dateStyle.setDataFormat(format.getFormat("dd.mm.yyyy"));
        birthdate.setCellStyle(dateStyle);
        
 
        // Нумерация лет начинается с 1900-го
        birthdate.setCellValue(new Date(110, 10, 10));
        
        // Меняем размер столбца
        sheet.autoSizeColumn(1);
        
        // Записываем всё в файл
        book.write(new FileOutputStream(file));
        book.close();
    }

Чтение

Теперь мы считаем из только что созданного файла то, что мы туда записали.

  • Для начала создадим HSSFWorkBook, передав в конструктор FileInputStream;
  • Получаем лист, передавая в getSheet() его номер или название;
  • Получаем строку, используя getRow();
  • Получаем ячейку, используя getCell();
  • Узнаём тип ячейки, используя на ней getCellType();
  • В зависимости от типа ячейки, читаем её значения, используя getStringCellValue(), getNumericCellValue() или getDateCellValue();
  • Закрываем workbook используя close().

Напомню, что дату Excel хранит как числа, т.е. тип ячейки всё равно будет CELL_TYPE_NUMERIC.

В виде кода это будет выглядеть следующим образом:

public static void readFromExcel(String file) throws IOException{
        HSSFWorkbook myExcelBook = new HSSFWorkbook(new FileInputStream(file));
        HSSFSheet myExcelSheet = myExcelBook.getSheet("Birthdays");
        HSSFRow row = myExcelSheet.getRow(0);
        
        if(row.getCell(0).getCellType() == HSSFCell.CELL_TYPE_STRING){
            String name = row.getCell(0).getStringCellValue();
            System.out.println("name : " + name);
        }
        
        if(row.getCell(1).getCellType() == HSSFCell.CELL_TYPE_NUMERIC){
            Date birthdate = row.getCell(1).getDateCellValue();
            System.out.println("birthdate :" + birthdate);
        }
        
        myExcelBook.close();
        
    }

В заключение

Как уже упомналось выше, чтение из xlsx файлов ничем принципиально не отличается — нужно только вместо HSSFWorkBook, HSSFSheet, HSSFRow (и прочих) из poi-XX.jar использовать XSSFWorkBook, XSSFSheet, XSSFRow из poi-ooxml-XX.jar. Это всё, что вам нужно знать для чтения и записи в файлы Excel. Разумеется, с помощью библиотеки Apache POI вы можете сделать гораздо больше, но эта статья должна помочь вам быстрее в ней освоиться.

Перевод статьи «How to Read Write Excel file in Java — POI Example»

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Работа с таблицей Excel из Java

Собственно возникла проблема — обработать данные из таблицы и на их основе получить другую таблицу.

Вариантов решения этой проблемы несколько:

  1. Макрос — единственной проблемой является VBA, на изучение которого времени нет совершенно, да и не нравится его синтаксис
  2. Приложение на C# тут вроде все хорошо, но к машине на которой будет выполняться данное приложение сразу предъявляется много дополнительных требований:
    • .NET Framework
    • Установленный офис
    • установленная основная сборка взаимодействия (PIA) для приложения Office

  3. связка Java и библиотека Apache POI—на этом способе я и хочу остановиться подробнее

Apache POI — это Java API для доступа к документам формата Microsoft.

Собственно для работы с таблицами Excel предназначен проект POI-HSSF. На данный момент есть 2 варианта библиотеки:

  1. POI 3.5 beta 5, and Office Open XML Support (2009-02-19)—идет работа над поддержкой формата Office 2007
  2. POI 3.2-FINAL Released (2008-10-19) — последний стабильный релиз

Я расскажу о работе с версией 3.2
Основным классом для работы с таблицей Excel является класс HSSFWorkbook пакета org.apache.poi.hssf.usermodel, представляющий книгу Excel.

Для чтения книги из файла можно применить следующий код:

public static HSSFWorkbook readWorkbook(String filename) {
       try {
               POIFSFileSystem fs = new POIFSFileSystem(new FileInputStream(filename));
               HSSFWorkbook wb = new HSSFWorkbook(fs);
               return wb;
       }
       catch (Exception e) {
               return null;
       }
}

Метод возвращает объект класса HSSFWorkbook если все удачно и null в другом случае.

Для сохранения изменений можно применить следующий метод:

public static void writeWorkbook(HSSFWorkbook wb, String fileName) {
       try {
               FileOutputStream fileOut = new FileOutputStream(fileName);
               wb.write(fileOut);
               fileOut.close();
       }
       catch (Exception e) {
               //Обработка ошибки
       }
}        

Метод записывает книгу wb в файл fileName

Для работы с листами рабочей книги предназначен класс HSSFSheet.
Объект класса HSSFSheet можно получить следующими способами:

  • По имени
    HSSFSheet sheet= wb.getSheet("Лист 3")
  • По номеру (нумерация начинается с 0)
    HSSFSheet sheet= wb.getSheet(0)
  • Создание нового листа
    HSSFSheet sheet= wb.createSheet(["имя листа"])

Следующим объектом является строка — HSSFRow.
Получить доступ к объекту строки можно также 3 способами:

  • По индексу (индексация начинается с 0)
    HSSFRow row = sheet.getRow(index)
  • Через итератор

    Iterator rowIter = sheet.rowIterator();
    while (rowIter.hasNext()) {
           HSSFRow row = (HSSFRow) rowIter.next();
    }

  • Создание новой строки
    HSSFRow row=sheet.createRow(0);

Ну и последним объектом на пути доступа к данным является объект класса HSSFCell — ячейка строки.
Получить доступ к ячейке можно из объекта строки следующими способами:

  • По индексу ячейки (индексация начинается с 0)
    HSSFCell cell = row.getCell(0);
  • Через итератор

    Iterator cellIter = row.cellIterator();
    while (cellIter.hasNext()) {
           HSSFCell cell = (HSSFCell) cellIter.next();
    }
    

  • Создание новой ячейки
    HSSFCell cell = row.createCell(0);

Из объекта ячейки можно уже получать и устанавливать непосредственно данные:

  • Логическое значение
    boolean b = cell.getBooleanCellValue();
    cell.setCellValue(b);
  • Дата
    Date date = cell.getDateCellValue();
    cell.setCellValue(date);
  • Числовое значение
    double d = cell.getNumericCellValue();
    cell.setCellValue(d);
  • Строковое значение
    String str = cell.getRichStringCellValue().getString();
    cell.setCellValue(new HSSFRichTextString(str));
  • Формула
    String formula = cell.getCellFormula();
    cell.setCellFormula(formula);

Этих знаний достаточно чтобы обрабатывать простые таблицы.
Библиотека также предоставляет богатые возможности по форматированию ячеек, по их слиянию, заморозке и т.д.
Подробное описание функций можно найти на их сайте.
Данный способ прежде всего ценен тем, что не требует установки самого офиса и пакета PIA.

Learn to read excel, write excel, evaluate formula cells and apply custom formatting to the generated excel files using Apache POI library with examples.

If we are building software for the HR or Finance domain, there is usually a requirement for generating excel reports across management levels. Apart from reports, we can also expect some input data for the applications coming in the form of excel sheets and the application is expected to support this requirement.

Apache POI is a well-trusted library among many other open-source libraries to handle such usecases involving excel files. Please note that, in addition, we can read and write MS Word and MS PowerPoint files also using the Apache POI library.

This Apache POI tutorial will discuss some everyday excel operations in real-life applications.

  1. 1. Maven Dependency
  2. 2. Important Classes in POI Library
  3. 3. Writing an Excel File
  4. 4. Reading an Excel File
  5. 5. Add and Evaluate Formula Cells
  6. 6. Formatting the Cells
  7. 7. Conclusion

1. Maven Dependency

If we are working on a maven project, we can include the Apache POI dependencies in pom.xml file using this:

<dependency>
  <groupId>org.apache.poi</groupId>
  <artifactId>poi</artifactId>
  <version>5.2.2</version>
</dependency>

<dependency>
  <groupId>org.apache.poi</groupId>
  <artifactId>poi-ooxml</artifactId>
  <version>5.2.2</version>
</dependency>

2. Important Classes in POI Library

  1. HSSF, XSSF and XSSF classes

    Apache POI main classes usually start with either HSSF, XSSF or SXSSF.

    • HSSF – is the POI Project’s pure Java implementation of the Excel 97(-2007) file format. e.g., HSSFWorkbook, HSSFSheet.
    • XSSF – is the POI Project’s pure Java implementation of the Excel 2007 OOXML (.xlsx) file format. e.g., XSSFWorkbook, XSSFSheet.
    • SXSSF (since 3.8-beta3) – is an API-compatible streaming extension of XSSF to be used when huge spreadsheets have to be produced and heap space is limited. e.g., SXSSFWorkbook, SXSSFSheet. SXSSF achieves its low memory footprint by limiting access to the rows within a sliding window, while XSSF gives access to all rows in the document.
  2. Row and Cell

    Apart from the above classes, Row and Cell interact with a particular row and a particular cell in an excel sheet.

  3. Styling Related Classes

    A wide range of classes like CellStyle, BuiltinFormats, ComparisonOperator, ConditionalFormattingRule, FontFormatting, IndexedColors, PatternFormatting, SheetConditionalFormatting etc. are used when you have to add formatting to a sheet, primarily based on some rules.

  4. FormulaEvaluator

    Another helpful class FormulaEvaluator is used to evaluate the formula cells in an excel sheet.

3. Writing an Excel File

I am taking this example first so we can reuse the excel sheet created by this code in further examples.

Writing excel using POI is very simple and involves the following steps:

  1. Create a workbook
  2. Create a sheet in workbook
  3. Create a row in sheet
  4. Add cells to sheet
  5. Repeat steps 3 and 4 to write more data

It seems very simple, right? Let’s have a look at the code doing these steps.

Java program to write an excel file using Apache POI library.

package com.howtodoinjava.demo.poi;
//import statements
public class WriteExcelDemo 
{
    public static void main(String[] args) 
    {
        //Blank workbook
        XSSFWorkbook workbook = new XSSFWorkbook(); 
         
        //Create a blank sheet
        XSSFSheet sheet = workbook.createSheet("Employee Data");
          
        //This data needs to be written (Object[])
        Map<String, Object[]> data = new TreeMap<String, Object[]>();
        data.put("1", new Object[] {"ID", "NAME", "LASTNAME"});
        data.put("2", new Object[] {1, "Amit", "Shukla"});
        data.put("3", new Object[] {2, "Lokesh", "Gupta"});
        data.put("4", new Object[] {3, "John", "Adwards"});
        data.put("5", new Object[] {4, "Brian", "Schultz"});
          
        //Iterate over data and write to sheet
        Set<String> keyset = data.keySet();
        int rownum = 0;
        for (String key : keyset)
        {
            Row row = sheet.createRow(rownum++);
            Object [] objArr = data.get(key);
            int cellnum = 0;
            for (Object obj : objArr)
            {
               Cell cell = row.createCell(cellnum++);
               if(obj instanceof String)
                    cell.setCellValue((String)obj);
                else if(obj instanceof Integer)
                    cell.setCellValue((Integer)obj);
            }
        }
        try
        {
            //Write the workbook in file system
            FileOutputStream out = new FileOutputStream(new File("howtodoinjava_demo.xlsx"));
            workbook.write(out);
            out.close();
            System.out.println("howtodoinjava_demo.xlsx written successfully on disk.");
        } 
        catch (Exception e) 
        {
            e.printStackTrace();
        }
    }
}
poi-demo-write-file

See Also: Appending Rows to Excel

4. Reading an Excel File

Reading an excel file using POI is also very simple if we divide this into steps.

  1. Create workbook instance from an excel sheet
  2. Get to the desired sheet
  3. Increment row number
  4. iterate over all cells in a row
  5. repeat steps 3 and 4 until all data is read

Let’s see all the above steps in code. I am writing the code to read the excel file created in the above example. It will read all the column names and the values in it – cell by cell.

Java program to read an excel file using Apache POI library.

package com.howtodoinjava.demo.poi;
//import statements
public class ReadExcelDemo 
{
    public static void main(String[] args) 
    {
        try
        {
            FileInputStream file = new FileInputStream(new File("howtodoinjava_demo.xlsx"));
 
            //Create Workbook instance holding reference to .xlsx file
            XSSFWorkbook workbook = new XSSFWorkbook(file);
 
            //Get first/desired sheet from the workbook
            XSSFSheet sheet = workbook.getSheetAt(0);
 
            //Iterate through each rows one by one
            Iterator<Row> rowIterator = sheet.iterator();
            while (rowIterator.hasNext()) 
            {
                Row row = rowIterator.next();
                //For each row, iterate through all the columns
                Iterator<Cell> cellIterator = row.cellIterator();
                 
                while (cellIterator.hasNext()) 
                {
                    Cell cell = cellIterator.next();
                    //Check the cell type and format accordingly
                    switch (cell.getCellType()) 
                    {
                        case Cell.CELL_TYPE_NUMERIC:
                            System.out.print(cell.getNumericCellValue() + "t");
                            break;
                        case Cell.CELL_TYPE_STRING:
                            System.out.print(cell.getStringCellValue() + "t");
                            break;
                    }
                }
                System.out.println("");
            }
            file.close();
        } 
        catch (Exception e) 
        {
            e.printStackTrace();
        }
    }
}

Program Output:

ID      NAME        LASTNAME
1.0     Amit        Shukla  
2.0     Lokesh      Gupta   
3.0     John        Adwards 
4.0     Brian       Schultz 

See Also: Apache POI – Read an Excel File using SAX Parser

5. Add and Evaluate Formula Cells

When working on complex excel sheets, we encounter many cells with formulas to calculate their values. These are formula cells. Apache POI also has excellent support for adding formula cells and evaluating already present formula cells.

Let’s see one example of how to add formula cells in excel?

The sheet has four cells in a row and the fourth one in the multiplication of all the previous 3 rows. So the formula will be: A2*B2*C2 (in the second row)

Java program to add formula in an excel file using Apache POI library.

public static void main(String[] args) 
{
    XSSFWorkbook workbook = new XSSFWorkbook();
    XSSFSheet sheet = workbook.createSheet("Calculate Simple Interest");
  
    Row header = sheet.createRow(0);
    header.createCell(0).setCellValue("Pricipal");
    header.createCell(1).setCellValue("RoI");
    header.createCell(2).setCellValue("T");
    header.createCell(3).setCellValue("Interest (P r t)");
      
    Row dataRow = sheet.createRow(1);
    dataRow.createCell(0).setCellValue(14500d);
    dataRow.createCell(1).setCellValue(9.25);
    dataRow.createCell(2).setCellValue(3d);
    dataRow.createCell(3).setCellFormula("A2*B2*C2");
      
    try {
        FileOutputStream out =  new FileOutputStream(new File("formulaDemo.xlsx"));
        workbook.write(out);
        out.close();
        System.out.println("Excel with foumula cells written successfully");
          
    } catch (FileNotFoundException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    }
}

Similarly, we want to read a file with formula cells and use the following logic to evaluate formula cells.

Java program to evaluate formula in an excel file using Apache POI library.

public static void readSheetWithFormula()
{
    try
    {
        FileInputStream file = new FileInputStream(new File("formulaDemo.xlsx"));
 
        //Create Workbook instance holding reference to .xlsx file
        XSSFWorkbook workbook = new XSSFWorkbook(file);
 
        FormulaEvaluator evaluator = workbook.getCreationHelper().createFormulaEvaluator();
         
        //Get first/desired sheet from the workbook
        XSSFSheet sheet = workbook.getSheetAt(0);
 
        //Iterate through each rows one by one
        Iterator<Row> rowIterator = sheet.iterator();
        while (rowIterator.hasNext()) 
        {
            Row row = rowIterator.next();
            //For each row, iterate through all the columns
            Iterator<Cell> cellIterator = row.cellIterator();
             
            while (cellIterator.hasNext()) 
            {
                Cell cell = cellIterator.next();
                //Check the cell type after eveluating formulae
                //If it is formula cell, it will be evaluated otherwise no change will happen
                switch (evaluator.evaluateInCell(cell).getCellType()) 
                {
                    case Cell.CELL_TYPE_NUMERIC:
                        System.out.print(cell.getNumericCellValue() + "tt");
                        break;
                    case Cell.CELL_TYPE_STRING:
                        System.out.print(cell.getStringCellValue() + "tt");
                        break;
                    case Cell.CELL_TYPE_FORMULA:
                        //Not again
                        break;
                }
            }
            System.out.println("");
        }
        file.close();
    } 
    catch (Exception e) 
    {
        e.printStackTrace();
    }
}

Program Output:

Pricipal        RoI         T       Interest (P r t)        
14500.0         9.25        3.0     402375.0  
poi-demo-write-formula

6. Formatting the Cells

So far we have seen examples of reading/writing and excel files using Apache POI. But, when creating a report in an excel file, it is essential to add formatting on cells that fit into any pre-determined criteria.

This formatting can be a different coloring based on a specific value range, expiry date limit etc.

In the below examples, we are taking a couple of such cell formatting examples for various purposes.

6.1. Cell value in a specific range

This code will color any cell in a range whose value is between a configured range. [e.g., between 50 and 70]

static void basedOnValue(Sheet sheet) 
{
    //Creating some random values
    sheet.createRow(0).createCell(0).setCellValue(84);
    sheet.createRow(1).createCell(0).setCellValue(74);
    sheet.createRow(2).createCell(0).setCellValue(50);
    sheet.createRow(3).createCell(0).setCellValue(51);
    sheet.createRow(4).createCell(0).setCellValue(49);
    sheet.createRow(5).createCell(0).setCellValue(41);
 
    SheetConditionalFormatting sheetCF = sheet.getSheetConditionalFormatting();
 
    //Condition 1: Cell Value Is   greater than  70   (Blue Fill)
    ConditionalFormattingRule rule1 = sheetCF.createConditionalFormattingRule(ComparisonOperator.GT, "70");
    PatternFormatting fill1 = rule1.createPatternFormatting();
    fill1.setFillBackgroundColor(IndexedColors.BLUE.index);
    fill1.setFillPattern(PatternFormatting.SOLID_FOREGROUND);
 
    //Condition 2: Cell Value Is  less than      50   (Green Fill)
    ConditionalFormattingRule rule2 = sheetCF.createConditionalFormattingRule(ComparisonOperator.LT, "50");
    PatternFormatting fill2 = rule2.createPatternFormatting();
    fill2.setFillBackgroundColor(IndexedColors.GREEN.index);
    fill2.setFillPattern(PatternFormatting.SOLID_FOREGROUND);
 
    CellRangeAddress[] regions = {
            CellRangeAddress.valueOf("A1:A6")
    };
 
    sheetCF.addConditionalFormatting(regions, rule1, rule2);
}
poi-demo-formatting-1

6.2. Highlight Duplicate Values

Highlight all cells which have duplicate values in observed cells.

static void formatDuplicates(Sheet sheet) {
    sheet.createRow(0).createCell(0).setCellValue("Code");
    sheet.createRow(1).createCell(0).setCellValue(4);
    sheet.createRow(2).createCell(0).setCellValue(3);
    sheet.createRow(3).createCell(0).setCellValue(6);
    sheet.createRow(4).createCell(0).setCellValue(3);
    sheet.createRow(5).createCell(0).setCellValue(5);
    sheet.createRow(6).createCell(0).setCellValue(8);
    sheet.createRow(7).createCell(0).setCellValue(0);
    sheet.createRow(8).createCell(0).setCellValue(2);
    sheet.createRow(9).createCell(0).setCellValue(8);
    sheet.createRow(10).createCell(0).setCellValue(6);
 
    SheetConditionalFormatting sheetCF = sheet.getSheetConditionalFormatting();
 
    // Condition 1: Formula Is   =A2=A1   (White Font)
    ConditionalFormattingRule rule1 = sheetCF.createConditionalFormattingRule("COUNTIF($A$2:$A$11,A2)>1");
    FontFormatting font = rule1.createFontFormatting();
    font.setFontStyle(false, true);
    font.setFontColorIndex(IndexedColors.BLUE.index);
 
    CellRangeAddress[] regions = {
            CellRangeAddress.valueOf("A2:A11")
    };
 
    sheetCF.addConditionalFormatting(regions, rule1);
 
    sheet.getRow(2).createCell(1).setCellValue("<== Duplicates numbers in the column are highlighted.  " +
            "Condition: Formula Is =COUNTIF($A$2:$A$11,A2)>1   (Blue Font)");
}
poi-demo-formatting-2

6.3. Alternate Color Rows in Different Colors

A simple code to color each alternate row in a different color.

static void shadeAlt(Sheet sheet) {
    SheetConditionalFormatting sheetCF = sheet.getSheetConditionalFormatting();
 
    // Condition 1: Formula Is   =A2=A1   (White Font)
    ConditionalFormattingRule rule1 = sheetCF.createConditionalFormattingRule("MOD(ROW(),2)");
    PatternFormatting fill1 = rule1.createPatternFormatting();
    fill1.setFillBackgroundColor(IndexedColors.LIGHT_GREEN.index);
    fill1.setFillPattern(PatternFormatting.SOLID_FOREGROUND);
 
    CellRangeAddress[] regions = {
            CellRangeAddress.valueOf("A1:Z100")
    };
 
    sheetCF.addConditionalFormatting(regions, rule1);
 
    sheet.createRow(0).createCell(1).setCellValue("Shade Alternating Rows");
    sheet.createRow(1).createCell(1).setCellValue("Condition: Formula Is  =MOD(ROW(),2)   (Light Green Fill)");
}
poi-demo-formatting-3

6.4. Color amounts that are going to expire in the next 30 days

A handy code for financial projects which keeps track of deadlines.

static void expiryInNext30Days(Sheet sheet) 
{
    CellStyle style = sheet.getWorkbook().createCellStyle();
    style.setDataFormat((short)BuiltinFormats.getBuiltinFormat("d-mmm"));
 
    sheet.createRow(0).createCell(0).setCellValue("Date");
    sheet.createRow(1).createCell(0).setCellFormula("TODAY()+29");
    sheet.createRow(2).createCell(0).setCellFormula("A2+1");
    sheet.createRow(3).createCell(0).setCellFormula("A3+1");
 
    for(int rownum = 1; rownum <= 3; rownum++) sheet.getRow(rownum).getCell(0).setCellStyle(style);
 
    SheetConditionalFormatting sheetCF = sheet.getSheetConditionalFormatting();
 
    // Condition 1: Formula Is   =A2=A1   (White Font)
    ConditionalFormattingRule rule1 = sheetCF.createConditionalFormattingRule("AND(A2-TODAY()>=0,A2-TODAY()<=30)");
    FontFormatting font = rule1.createFontFormatting();
    font.setFontStyle(false, true);
    font.setFontColorIndex(IndexedColors.BLUE.index);
 
    CellRangeAddress[] regions = {
            CellRangeAddress.valueOf("A2:A4")
    };
 
    sheetCF.addConditionalFormatting(regions, rule1);
 
    sheet.getRow(0).createCell(1).setCellValue("Dates within the next 30 days are highlighted");
}
poi-demo-formatting-4

I am ending this apache poi tutorial here to keep the post within a limit.

7. Conclusion

In this tutorial, we learned to read excel, write excel, set and evaluate formula cells, and format the cells with color codings using the Apache POI library.

Happy Learning !!

Source Code on Github

I want to read and write an Excel file from Java with 3 columns and N rows, printing one string in each cell. Can anyone give me simple code snippet for this? Do I need to use any external lib or does Java have built-in support for it?

I want to do the following:

for(i=0; i <rows; i++)
     //read [i,col1] ,[i,col2], [i,col3]

for(i=0; i<rows; i++)
    //write [i,col1], [i,col2], [i,col3]

Paolo Forgia's user avatar

Paolo Forgia

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asked Oct 4, 2009 at 10:54

user177785's user avatar

1

Try the Apache POI HSSF. Here’s an example on how to read an excel file:

try {
    POIFSFileSystem fs = new POIFSFileSystem(new FileInputStream(file));
    HSSFWorkbook wb = new HSSFWorkbook(fs);
    HSSFSheet sheet = wb.getSheetAt(0);
    HSSFRow row;
    HSSFCell cell;

    int rows; // No of rows
    rows = sheet.getPhysicalNumberOfRows();

    int cols = 0; // No of columns
    int tmp = 0;

    // This trick ensures that we get the data properly even if it doesn't start from first few rows
    for(int i = 0; i < 10 || i < rows; i++) {
        row = sheet.getRow(i);
        if(row != null) {
            tmp = sheet.getRow(i).getPhysicalNumberOfCells();
            if(tmp > cols) cols = tmp;
        }
    }

    for(int r = 0; r < rows; r++) {
        row = sheet.getRow(r);
        if(row != null) {
            for(int c = 0; c < cols; c++) {
                cell = row.getCell((short)c);
                if(cell != null) {
                    // Your code here
                }
            }
        }
    }
} catch(Exception ioe) {
    ioe.printStackTrace();
}

On the documentation page you also have examples of how to write to excel files.

Greatmar2's user avatar

answered Oct 4, 2009 at 10:59

rogeriopvl's user avatar

rogeriopvlrogeriopvl

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7

Apache POI can do this for you. Specifically the HSSF module. The quick guide is most useful. Here’s how to do what you want — specifically create a sheet and write it out.

Workbook wb = new HSSFWorkbook();
//Workbook wb = new XSSFWorkbook();
CreationHelper createHelper = wb.getCreationHelper();
Sheet sheet = wb.createSheet("new sheet");

// Create a row and put some cells in it. Rows are 0 based.
Row row = sheet.createRow((short)0);
// Create a cell and put a value in it.
Cell cell = row.createCell(0);
cell.setCellValue(1);

// Or do it on one line.
row.createCell(1).setCellValue(1.2);
row.createCell(2).setCellValue(
createHelper.createRichTextString("This is a string"));
row.createCell(3).setCellValue(true);

// Write the output to a file
FileOutputStream fileOut = new FileOutputStream("workbook.xls");
wb.write(fileOut);
fileOut.close();

Morteza Jalambadani's user avatar

answered Oct 4, 2009 at 10:57

Brian Agnew's user avatar

Brian AgnewBrian Agnew

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2

First add all these jar files in your project class path:

  1. poi-scratchpad-3.7-20101029
  2. poi-3.2-FINAL-20081019
  3. poi-3.7-20101029
  4. poi-examples-3.7-20101029
  5. poi-ooxml-3.7-20101029
  6. poi-ooxml-schemas-3.7-20101029
  7. xmlbeans-2.3.0
  8. dom4j-1.6.1

Code for writing in a excel file:

public static void main(String[] args) {
    //Blank workbook
    XSSFWorkbook workbook = new XSSFWorkbook();

    //Create a blank sheet
    XSSFSheet sheet = workbook.createSheet("Employee Data");

    //This data needs to be written (Object[])
    Map<String, Object[]> data = new TreeMap<String, Object[]>();
    data.put("1", new Object[]{"ID", "NAME", "LASTNAME"});
    data.put("2", new Object[]{1, "Amit", "Shukla"});
    data.put("3", new Object[]{2, "Lokesh", "Gupta"});
    data.put("4", new Object[]{3, "John", "Adwards"});
    data.put("5", new Object[]{4, "Brian", "Schultz"});

    //Iterate over data and write to sheet
    Set<String> keyset = data.keySet();

    int rownum = 0;
    for (String key : keyset) 
    {
        //create a row of excelsheet
        Row row = sheet.createRow(rownum++);

        //get object array of prerticuler key
        Object[] objArr = data.get(key);

        int cellnum = 0;

        for (Object obj : objArr) 
        {
            Cell cell = row.createCell(cellnum++);
            if (obj instanceof String) 
            {
                cell.setCellValue((String) obj);
            }
            else if (obj instanceof Integer) 
            {
                cell.setCellValue((Integer) obj);
            }
        }
    }
    try 
    {
        //Write the workbook in file system
        FileOutputStream out = new FileOutputStream(new File("C:\Documents and Settings\admin\Desktop\imp data\howtodoinjava_demo.xlsx"));
        workbook.write(out);
        out.close();
        System.out.println("howtodoinjava_demo.xlsx written successfully on disk.");
    } 
    catch (Exception e)
    {
        e.printStackTrace();
    }
}

Code for reading from excel file

/*
* To change this template, choose Tools | Templates
* and open the template in the editor.
*/

public static void main(String[] args) {
    try {
        FileInputStream file = new FileInputStream(new File("C:\Documents and Settings\admin\Desktop\imp data\howtodoinjava_demo.xlsx"));

        //Create Workbook instance holding reference to .xlsx file
        XSSFWorkbook workbook = new XSSFWorkbook(file);

        //Get first/desired sheet from the workbook
        XSSFSheet sheet = workbook.getSheetAt(0);

        //Iterate through each rows one by one
        Iterator<Row> rowIterator = sheet.iterator();
        while (rowIterator.hasNext())
        {
            Row row = rowIterator.next();
            //For each row, iterate through all the columns
            Iterator<Cell> cellIterator = row.cellIterator();

            while (cellIterator.hasNext()) 
            {
                Cell cell = cellIterator.next();
                //Check the cell type and format accordingly
                switch (cell.getCellType()) 
                {
                    case Cell.CELL_TYPE_NUMERIC:
                        System.out.print(cell.getNumericCellValue() + "t");
                        break;
                    case Cell.CELL_TYPE_STRING:
                        System.out.print(cell.getStringCellValue() + "t");
                        break;
                }
            }
            System.out.println("");
        }
        file.close();
    } catch (Exception e) {
        e.printStackTrace();
    }
}

Prasad Jadhav's user avatar

answered Aug 2, 2013 at 9:15

Prashant Tiwari's user avatar

0

You can also consider JExcelApi. I find it better designed than POI. There’s a tutorial here.

answered Oct 4, 2009 at 13:06

javashlook's user avatar

javashlookjavashlook

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3

There is a new easy and very cool tool (10x to Kfir): xcelite

Write:

public class User { 

  @Column (name="Firstname")
  private String firstName;

  @Column (name="Lastname")
  private String lastName;

  @Column
  private long id; 

  @Column
  private Date birthDate; 
}

Xcelite xcelite = new Xcelite();    
XceliteSheet sheet = xcelite.createSheet("users");
SheetWriter<User> writer = sheet.getBeanWriter(User.class);
List<User> users = new ArrayList<User>();
// ...fill up users
writer.write(users); 
xcelite.write(new File("users_doc.xlsx"));

Read:

Xcelite xcelite = new Xcelite(new File("users_doc.xlsx"));
XceliteSheet sheet = xcelite.getSheet("users");
SheetReader<User> reader = sheet.getBeanReader(User.class);
Collection<User> users = reader.read();

Johannes Jander's user avatar

answered Dec 23, 2014 at 8:21

Ran Adler's user avatar

Ran AdlerRan Adler

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0

For reading a xlsx file we can use Apache POI libs
Try this:

public static void readXLSXFile() throws IOException
    {
        InputStream ExcelFileToRead = new FileInputStream("C:/Test.xlsx");
        XSSFWorkbook  wb = new XSSFWorkbook(ExcelFileToRead);

        XSSFWorkbook test = new XSSFWorkbook(); 

        XSSFSheet sheet = wb.getSheetAt(0);
        XSSFRow row; 
        XSSFCell cell;

        Iterator rows = sheet.rowIterator();

        while (rows.hasNext())
        {
            row=(XSSFRow) rows.next();
            Iterator cells = row.cellIterator();
            while (cells.hasNext())
            {
                cell=(XSSFCell) cells.next();

                if (cell.getCellType() == XSSFCell.CELL_TYPE_STRING)
                {
                    System.out.print(cell.getStringCellValue()+" ");
                }
                else if(cell.getCellType() == XSSFCell.CELL_TYPE_NUMERIC)
                {
                    System.out.print(cell.getNumericCellValue()+" ");
                }
                else
                {
                    //U Can Handel Boolean, Formula, Errors
                }
            }
            System.out.println();
        }

    }

DarkMental's user avatar

answered Apr 13, 2017 at 8:16

KIBOU Hassan's user avatar

.csv or POI will certainly do it, but you should be aware of Andy Khan’s JExcel. I think it’s by far the best Java library for working with Excel there is.

answered Oct 4, 2009 at 12:50

duffymo's user avatar

duffymoduffymo

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2

A simple CSV file should suffice

answered Oct 4, 2009 at 11:01

John La Rooy's user avatar

John La RooyJohn La Rooy

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8

String path="C:\Book2.xlsx";
try {

        File f = new File( path );
        Workbook wb = WorkbookFactory.create(f);
        Sheet mySheet = wb.getSheetAt(0);
        Iterator<Row> rowIter = mySheet.rowIterator();
        for ( Iterator<Row> rowIterator = mySheet.rowIterator() ;rowIterator.hasNext(); )
        {
            for (  Iterator<Cell> cellIterator = ((Row)rowIterator.next()).cellIterator() ; cellIterator.hasNext() ;  ) 
            {
                System.out.println ( ( (Cell)cellIterator.next() ).toString() );
            }
            System.out.println( " **************************************************************** ");
        }
    } catch ( Exception e )
    {
        System.out.println( "exception" );
        e.printStackTrace();
    }

and make sure to have added the jars poi and poi-ooxml (org.apache.poi) to your project

instinct's user avatar

instinct

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answered Apr 11, 2014 at 10:24

Toumi's user avatar

ToumiToumi

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For reading data from .xlsx workbooks we need to use XSSFworkbook classes.

XSSFWorkbook xlsxBook = new XSSFWorkbook(fis);

XSSFSheet sheet = xlsxBook.getSheetAt(0); etc.

We need to use Apache-poi 3.9 @ http://poi.apache.org/

For detailed info with example visit
: http://java-recent.blogspot.in

CuberChase's user avatar

CuberChase

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answered Jun 18, 2013 at 1:47

Satish Reddy's user avatar

1

Sure , you will find the code below useful and easy to read and write. This is a util class which you can use in your main method and then you are good to use all methods below.

     public class ExcelUtils {
     private static XSSFSheet ExcelWSheet;
     private static XSSFWorkbook ExcelWBook;
     private static XSSFCell Cell;
     private static XSSFRow Row;
     File fileName = new File("C:\Users\satekuma\Pro\Fund.xlsx");
     public void setExcelFile(File Path, String SheetName) throws Exception                

    try {
        FileInputStream ExcelFile = new FileInputStream(Path);
        ExcelWBook = new XSSFWorkbook(ExcelFile);
        ExcelWSheet = ExcelWBook.getSheet(SheetName);
    } catch (Exception e) {
        throw (e);
    }

}


      public static String getCellData(int RowNum, int ColNum) throws Exception {

    try {
        Cell = ExcelWSheet.getRow(RowNum).getCell(ColNum);
        String CellData = Cell.getStringCellValue();
        return CellData;
    } catch (Exception e) {

        return "";

    }

}
public static void setCellData(String Result, int RowNum, int ColNum, File Path) throws Exception {

    try {
        Row = ExcelWSheet.createRow(RowNum - 1);
        Cell = Row.createCell(ColNum - 1);
        Cell.setCellValue(Result);
        FileOutputStream fileOut = new FileOutputStream(Path);
        ExcelWBook.write(fileOut);
        fileOut.flush();
        fileOut.close();
    } catch (Exception e) {

        throw (e);

    }

}

}

Hrach Ghapantsyan's user avatar

answered May 6, 2015 at 14:58

satender's user avatar

satendersatender

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using spring apache poi repo

if (fileName.endsWith(".xls")) {



File myFile = new File("file location" + fileName);
                FileInputStream fis = new FileInputStream(myFile);

                org.apache.poi.ss.usermodel.Workbook workbook = null;
                try {
                    workbook = WorkbookFactory.create(fis);
                } catch (InvalidFormatException e) {

                    e.printStackTrace();
                }


                org.apache.poi.ss.usermodel.Sheet sheet = workbook.getSheetAt(0);


                Iterator<Row> rowIterator = sheet.iterator();


                while (rowIterator.hasNext()) {
                    Row row = rowIterator.next();

                    Iterator<Cell> cellIterator = row.cellIterator();
                    while (cellIterator.hasNext()) {

                        Cell cell = cellIterator.next();
                        switch (cell.getCellType()) {
                        case Cell.CELL_TYPE_STRING:
                            System.out.print(cell.getStringCellValue());
                            break;
                        case Cell.CELL_TYPE_BOOLEAN:
                            System.out.print(cell.getBooleanCellValue());
                            break;
                        case Cell.CELL_TYPE_NUMERIC:
                            System.out.print(cell.getNumericCellValue());
                            break;
                        }
                        System.out.print(" - ");
                    }
                    System.out.println();
                }
            }

goto's user avatar

goto

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answered Feb 22, 2017 at 9:53

Rahul.P's user avatar

I edited the most voted one a little cuz it didn’t count blanks columns or rows well not totally, so here is my code i tested it and now can get any cell in any part of an excel file. also now u can have blanks columns between filled column and it will read them

  try {
POIFSFileSystem fs = new POIFSFileSystem(new FileInputStream(Dir));
HSSFWorkbook wb = new HSSFWorkbook(fs);
HSSFSheet sheet = wb.getSheetAt(0);
HSSFRow row;
HSSFCell cell;

int rows; // No of rows
rows = sheet.getPhysicalNumberOfRows();

int cols = 0; // No of columns
int tmp = 0;
int cblacks=0;

// This trick ensures that we get the data properly even if it doesn't start from first few rows
for(int i = 0; i <= 10 || i <= rows; i++) {
    row = sheet.getRow(i);
    if(row != null) {
        tmp = sheet.getRow(i).getPhysicalNumberOfCells();
        if(tmp >= cols) cols = tmp;else{rows++;cblacks++;}
    }

    cols++;
}
cols=cols+cblacks;
for(int r = 0; r < rows; r++) {
    row = sheet.getRow(r);
    if(row != null) {
        for(int c = 0; c < cols; c++) {
            cell = row.getCell(c);
            if(cell != null) {
                System.out.print(cell+"n");//Your Code here
            }
        }
    }
}} catch(Exception ioe) {
ioe.printStackTrace();}

answered Oct 4, 2015 at 20:16

Nahuel Illescas's user avatar

If column number are varing you can use this

package com.org.tests;
import org.apache.poi.xssf.usermodel.*;
import java.io.FileInputStream;
import java.io.IOException;

public class ExcelSimpleTest 
{   
    String path;
    public FileInputStream fis = null;
    private XSSFWorkbook workbook = null;
    private XSSFSheet sheet = null;
    private XSSFRow row   =null;
    private XSSFCell cell = null;

    public ExcelSimpleTest() throws IOException
    {
        path = System.getProperty("user.dir")+"\resources\Book1.xlsx";
        fis = new FileInputStream(path); 
        workbook = new XSSFWorkbook(fis);
        sheet = workbook.getSheetAt(0);
    }
    public void ExelWorks()
    {
        int index = workbook.getSheetIndex("Sheet1");
        sheet = workbook.getSheetAt(index);
        int rownumber=sheet.getLastRowNum()+1;  

        for (int i=1; i<rownumber; i++ )
        {
            row = sheet.getRow(i);
            int colnumber = row.getLastCellNum();
            for (int j=0; j<colnumber; j++ )
            {
                cell = row.getCell(j);
                System.out.println(cell.getStringCellValue());
            }
        }
    }   
    public static void main(String[] args) throws IOException 
    {
        ExcelSimpleTest excelwork = new ExcelSimpleTest();
        excelwork.ExelWorks();
    }
}

The corresponding mavendependency can be found here

Ohmen's user avatar

Ohmen

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answered Aug 26, 2016 at 6:06

Senthil Kumar Natarajan's user avatar

1

Another way to read/write Excel files is to use Windmill. It provides a fluent API to process Excel and CSV files.

Import data

try (Stream<Row> rowStream = Windmill.parse(FileSource.of(new FileInputStream("myFile.xlsx")))) {
  rowStream
    // skip the header row that contains the column names
    .skip(1)
    .forEach(row -> {
      System.out.println(
        "row n°" + row.rowIndex()
        + " column 'User login' value : " + row.cell("User login").asString()
        + " column n°3 number value : " + row.cell(2).asDouble().value() // index is zero-based
      );
    });
}

Export data

Windmill
  .export(Arrays.asList(bean1, bean2, bean3))
  .withHeaderMapping(
    new ExportHeaderMapping<Bean>()
      .add("Name", Bean::getName)
      .add("User login", bean -> bean.getUser().getLogin())
  )
  .asExcel()
  .writeTo(new FileOutputStream("Export.xlsx"));

answered Sep 30, 2017 at 15:07

amanteaux's user avatar

amanteauxamanteaux

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You need Apache POI library and this code below should help you

    import java.io.File;
    import java.io.FileInputStream;
    import java.io.FileNotFoundException;
    import java.io.FileOutputStream;
    import java.io.IOException;
    import java.util.ArrayList;
    import java.util.List;
    import java.util.Iterator;
    //*************************************************************
    import org.apache.poi.ss.usermodel.Sheet;
    import org.apache.poi.ss.usermodel.Cell;
    import org.apache.poi.ss.usermodel.Row;
    import org.apache.poi.ss.usermodel.Workbook;
    import org.apache.poi.xssf.usermodel.XSSFSheet;
    import org.apache.poi.xssf.usermodel.XSSFWorkbook;

    //*************************************************************
   public class AdvUse {

    private static Workbook wb ; 
    private static Sheet sh ; 
    private static FileInputStream fis ; 
    private static FileOutputStream fos  ; 
    private static Row row  ; 
    private static Cell cell  ;
    private static String ExcelPath ; 

    //*************************************************************
    public static void setEcxelFile(String ExcelPath, String SheetName) throws Exception {
    try {
   File f= new File(ExcelPath); 
   if(!f.exists()){
       f.createNewFile();
       System.out.println("File not Found so created");
   }

    fis = new FileInputStream("./testData.xlsx");
    wb = WorkbookFactory.create(fis); 
    sh = wb.getSheet("SheetName");
    if(sh == null){
        sh = wb.getSheet(SheetName); 
    }
    }catch(Exception e)
    {System.out.println(e.getMessage());
    }
    }

      //*************************************************************
      public static void setCellData(String text , int rowno , int colno){
    try{
        row = sh.getRow(rowno);
        if(row == null){
            row = sh.createRow(rowno);
        }
        cell = row.getCell(colno);
        if(cell!=null){
            cell.setCellValue(text);

        }
        else{
            cell = row.createCell(colno);
            cell.setCellValue(text);

        }
        fos = new FileOutputStream(ExcelPath);
        wb.write(fos);
        fos.flush();
        fos.close();
    }catch(Exception e){
        System.out.println(e.getMessage());
    }
    }

      //*************************************************************
      public static String getCellData(int rowno , int colno){
        try{

            cell = sh.getRow(rowno).getCell(colno); 
            String CellData = null ;
            switch(cell.getCellType()){
            case  STRING :
                CellData = cell.getStringCellValue();
               break ; 
            case NUMERIC : 
                CellData = Double.toString(cell.getNumericCellValue());
                if(CellData.contains(".o")){
                    CellData = CellData.substring(0,CellData.length()-2);

                }
            break ; 
            case BLANK : 
            CellData = ""; break ; 

            }
            return CellData;
        }catch(Exception e){return ""; }
    }

       //*************************************************************
      public static int getLastRow(){
        return sh.getLastRowNum();
    }

answered Mar 30, 2019 at 16:48

Abdo Bmz's user avatar

Abdo BmzAbdo Bmz

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You can not read & write same file in parallel(Read-write lock). But, we can do parallel operations on temporary data(i.e. Input/output stream). Write the data to file only after closing the input stream. Below steps should be followed.

  • Open the file to Input stream
  • Open the same file to an Output Stream
  • Read and do the processing
  • Write contents to output stream.
  • Close the read/input stream, close file
  • Close output stream, close file.

Apache POI — read/write same excel example

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.sql.Date;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;

import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.Row;
import org.apache.poi.xssf.usermodel.XSSFSheet;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;


public class XLSXReaderWriter {

    public static void main(String[] args) {

        try {
            File excel = new File("D://raju.xlsx");
            FileInputStream fis = new FileInputStream(excel);
            XSSFWorkbook book = new XSSFWorkbook(fis);
            XSSFSheet sheet = book.getSheetAt(0);

            Iterator<Row> itr = sheet.iterator();

            // Iterating over Excel file in Java
            while (itr.hasNext()) {
                Row row = itr.next();

                // Iterating over each column of Excel file
                Iterator<Cell> cellIterator = row.cellIterator();
                while (cellIterator.hasNext()) {

                    Cell cell = cellIterator.next();

                    switch (cell.getCellType()) {
                    case Cell.CELL_TYPE_STRING:
                        System.out.print(cell.getStringCellValue() + "t");
                        break;
                    case Cell.CELL_TYPE_NUMERIC:
                        System.out.print(cell.getNumericCellValue() + "t");
                        break;
                    case Cell.CELL_TYPE_BOOLEAN:
                        System.out.print(cell.getBooleanCellValue() + "t");
                        break;
                    default:

                    }
                }
                System.out.println("");
            }

            // writing data into XLSX file
            Map<String, Object[]> newData = new HashMap<String, Object[]>();
            newData.put("1", new Object[] { 1d, "Raju", "75K", "dev",
                    "SGD" });
            newData.put("2", new Object[] { 2d, "Ramesh", "58K", "test",
                    "USD" });
            newData.put("3", new Object[] { 3d, "Ravi", "90K", "PMO",
                    "INR" });

            Set<String> newRows = newData.keySet();
            int rownum = sheet.getLastRowNum();

            for (String key : newRows) {
                Row row = sheet.createRow(rownum++);
                Object[] objArr = newData.get(key);
                int cellnum = 0;
                for (Object obj : objArr) {
                    Cell cell = row.createCell(cellnum++);
                    if (obj instanceof String) {
                        cell.setCellValue((String) obj);
                    } else if (obj instanceof Boolean) {
                        cell.setCellValue((Boolean) obj);
                    } else if (obj instanceof Date) {
                        cell.setCellValue((Date) obj);
                    } else if (obj instanceof Double) {
                        cell.setCellValue((Double) obj);
                    }
                }
            }

            // open an OutputStream to save written data into Excel file
            FileOutputStream os = new FileOutputStream(excel);
            book.write(os);
            System.out.println("Writing on Excel file Finished ...");

            // Close workbook, OutputStream and Excel file to prevent leak
            os.close();
            book.close();
            fis.close();

        } catch (FileNotFoundException fe) {
            fe.printStackTrace();
        } catch (IOException ie) {
            ie.printStackTrace();
        }
    }
}

Community's user avatar

answered Jul 20, 2018 at 21:46

Raju's user avatar

RajuRaju

2,8628 gold badges38 silver badges57 bronze badges

Please use Apache POI libs and try this.

    try
    {
        FileInputStream x = new FileInputStream(new File("/Users/rajesh/Documents/rajesh.xls"));

        //Create Workbook instance holding reference to .xlsx file
        Workbook workbook = new HSSFWorkbook(x);

        //Get first/desired sheet from the workbook
        Sheet sheet = workbook.getSheetAt(0);

        //Iterate through each rows one by one
        for (Iterator<Row> iterator = sheet.iterator(); iterator.hasNext();) {
            Row row = (Row) iterator.next();
            for (Iterator<Cell> iterator2 = row.iterator(); iterator2
                    .hasNext();) {
                Cell cell = (Cell) iterator2.next();
                System.out.println(cell.getStringCellValue());              
            }               
        }         
        x.close();
    }
    catch (Exception e)
    {
        e.printStackTrace();
    }
   }
}

Majid Laissi's user avatar

Majid Laissi

19k19 gold badges65 silver badges105 bronze badges

answered Nov 28, 2014 at 11:41

Rajesh Chaudhary's user avatar

When using the apache poi 4.1.2. The celltype changes a bit. Below is an example

    try {
        File excel = new File("/home/name/Downloads/bb.xlsx");
        FileInputStream fis = new FileInputStream(excel);
        XSSFWorkbook book = new XSSFWorkbook(fis);
        XSSFSheet sheet = book.getSheetAt(0);

        Iterator<Row> itr = sheet.iterator();

        // Iterating over Excel file in Java
        while (itr.hasNext()) {
            Row row = itr.next();

            Iterator<Cell> cellIterator = row.cellIterator();
            while (cellIterator.hasNext()) {



                Cell cell = cellIterator.next();



                switch (cell.getCellType()) {
                case STRING:
                    System.out.print(cell.getStringCellValue() + "t");
                    break;
                case NUMERIC:
                    System.out.print(cell.getNumericCellValue() + "t");
                    break;
                case BOOLEAN:
                    System.out.print(cell.getBooleanCellValue() + "t");
                    break;
                default:


                }
            }
            System.out.println("");}
        }catch (Exception e) {
            // TODO: handle exception
            e.printStackTrace();
        }

answered May 22, 2020 at 8:44

mumbasa's user avatar

mumbasamumbasa

5526 silver badges11 bronze badges

If you go for third party library option, try using Aspose.Cells API that enables Java Applications to create (read/write) and manage Excel spreadsheets efficiently without requiring Microsoft Excel.

e.g

Sample code:

1.

//Load sample workbook
Workbook wb = new Workbook(dirPath + "sample.xlsx");

//Access first worksheet
Worksheet ws = wb.getWorksheets().get(0);

//Access cells iterator
Iterator itrat = ws.getCells().iterator();

//Print cells name in iterator
while(itrat.hasNext())
{
    Cell cell = (Cell)itrat.next();

    System.out.println(cell.getName() + ": " + cell.getStringValue().trim());
}
Workbook book = new Workbook("sample.xlsx");
Worksheet sheet = book.getWorksheets().get(0);
Range range = sheet.getCells().getMaxDisplayRange();//You may also create your desired range (in the worksheet) using, e.g sheet.getCells().createRange("A1", "J11");
Iterator rangeIterator = range.iterator();
while(rangeIterator.hasNext())
{
Cell cell = (Cell)rangeIterator.next();
//your code goes here.
}

Hope, this helps a bit.

PS. I am working as Support developer/ Evangelist at Aspose.

answered Sep 2, 2020 at 19:29

Amjad Sahi's user avatar

Amjad SahiAmjad Sahi

1,7531 gold badge9 silver badges15 bronze badges

If you need to do anything more with office documents in Java, go for POI as mentioned.

For simple reading/writing an excel document like you requested, you can use the CSV format (also as mentioned):

import java.io.BufferedReader;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.Scanner;

public class CsvWriter {
 public static void main(String args[]) throws IOException {

  String fileName = "test.xls";

  PrintWriter out = new PrintWriter(new FileWriter(fileName));
  out.println("a,b,c,d");
  out.println("e,f,g,h");
  out.println("i,j,k,l");
  out.close();

  BufferedReader in = new BufferedReader(new FileReader(fileName));
  String line = null;
  while ((line = in.readLine()) != null) {

   Scanner scanner = new Scanner(line);
   String sep = "";
   while (scanner.hasNext()) {
    System.out.println(sep + scanner.next());
    sep = ",";
   }
  }
  in.close();
 }
}

answered Oct 4, 2009 at 12:02

Adriaan Koster's user avatar

Adriaan KosterAdriaan Koster

15.8k5 gold badges45 silver badges60 bronze badges

This will write a JTable to a tab separated file that can be easily imported into Excel. This works.

If you save an Excel worksheet as an XML document you could also build the XML file for EXCEL with code. I have done this with word so you do not have to use third-party packages.

This could code have the JTable taken out and then just write a tab separated to any text file and then import into Excel. I hope this helps.

Code:

import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import javax.swing.JTable;
import javax.swing.table.TableModel;

public class excel {
    String columnNames[] = { "Column 1", "Column 2", "Column 3" };

    // Create some data
    String dataValues[][] =
    {
        { "12", "234", "67" },
        { "-123", "43", "853" },
        { "93", "89.2", "109" },
        { "279", "9033", "3092" }
    };

    JTable table;

    excel() {
        table = new JTable( dataValues, columnNames );
    }


    public void toExcel(JTable table, File file){
        try{
            TableModel model = table.getModel();
            FileWriter excel = new FileWriter(file);

            for(int i = 0; i < model.getColumnCount(); i++){
                excel.write(model.getColumnName(i) + "t");
            }

            excel.write("n");

            for(int i=0; i< model.getRowCount(); i++) {
                for(int j=0; j < model.getColumnCount(); j++) {
                    excel.write(model.getValueAt(i,j).toString()+"t");
                }
                excel.write("n");
            }

            excel.close();

        }catch(IOException e){ System.out.println(e); }
    }

    public static void main(String[] o) {
        excel cv = new excel();
        cv.toExcel(cv.table,new File("C:\Users\itpr13266\Desktop\cs.tbv"));
    }
}

answered Feb 26, 2014 at 22:58

Doug Hauf's user avatar

Doug HaufDoug Hauf

3,0158 gold badges45 silver badges69 bronze badges

1

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