Apache POI: How to set styles in Spreadsheets?

In this tutorial, we will discuss how to set styles in an excel document. We are considering that the excel file contains multiple sheets.

Dependencies

First, download the dependency files as mentioned in the Introduction to Apache POI For Manipulation of MS Office Documents with Java tutorial. After downloading the libraries, you have to add them to JAVA_PATH. Alternatively, you can create an Eclipse project and add them to the project as a library. You are being suggested to add the libraries as internal libraries instead of external libraries.

If you are not familiar with library linking, follow these steps.

Create a directory, lib, in your project. Paste the jars in the lib directory. Right-click on the project, select Properties, go to Java Build Path, click on Add Jars and browse the lib directory you have created. It's done!

Explanation of Source Code

•     Create an instance of XSSFWorkbook class for .xlsx file.
•     Create an instance of XSSFSheet. A new sheet can be created by createSheet() method of class XSSFWorkbook, by passing name of the sheet as an argument.
•     Prepare content to be written in sheet using Map
•     Now create Rows using createRow() method and create cells using createCell() methods as per your requirements.
•     Create an instance of FileOutputStream for the Demo.xlsx file.
•     Finally, write the content.

Try the following code.

package com.ba.demo.poi; import java.io.FileOutputStream; import org.apache.poi.hssf.record.CFRuleRecord.ComparisonOperator; import org.apache.poi.ss.usermodel.BuiltinFormats; import org.apache.poi.ss.usermodel.CellStyle; import org.apache.poi.ss.usermodel.ConditionalFormattingRule; import org.apache.poi.ss.usermodel.FontFormatting; import org.apache.poi.ss.usermodel.IndexedColors; import org.apache.poi.ss.usermodel.PatternFormatting; import org.apache.poi.ss.usermodel.Sheet; import org.apache.poi.ss.usermodel.SheetConditionalFormatting; import org.apache.poi.ss.usermodel.Workbook; import org.apache.poi.ss.util.CellRangeAddress; import org.apache.poi.xssf.usermodel.XSSFWorkbook; public class ExcelStylingDemo { public static void main(String[] args) throws Exception { Workbook workbook = new XSSFWorkbook(); styleBasedOnValue(workbook.createSheet("Value Based formatting")); formatDuplicates(workbook.createSheet("Duplicates formatting")); shadeAlt(workbook.createSheet("Alternate rows")); expiryInNext30Days(workbook.createSheet("Soon Expired Payments")); FileOutputStream fileOutputStream = new FileOutputStream("styleDemo.xlsx"); workbook.write(fileOutputStream); fileOutputStream.close(); } static void styleBasedOnValue(Sheet sheet) { 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 sheetConditionalFormatting = sheet.getSheetConditionalFormatting(); ConditionalFormattingRule conditionalFormattingRule1 = sheetConditionalFormatting .createConditionalFormattingRule(ComparisonOperator.GT, "70"); PatternFormatting patternFormatting1 = conditionalFormattingRule1.createPatternFormatting(); patternFormatting1.setFillBackgroundColor(IndexedColors.BLUE.index); patternFormatting1.setFillPattern(PatternFormatting.SOLID_FOREGROUND); ConditionalFormattingRule conditionalFormattingRule2 = sheetConditionalFormatting .createConditionalFormattingRule(ComparisonOperator.LT, "50"); PatternFormatting patternFormatting2 = conditionalFormattingRule2.createPatternFormatting(); patternFormatting2.setFillBackgroundColor(IndexedColors.GREEN.index); patternFormatting2.setFillPattern(PatternFormatting.SOLID_FOREGROUND); CellRangeAddress[] cellRangeAddresses = { CellRangeAddress.valueOf("A1:A6") }; sheetConditionalFormatting.addConditionalFormatting(cellRangeAddresses, conditionalFormattingRule1, conditionalFormattingRule2); } 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 sheetConditionalFormatting = sheet.getSheetConditionalFormatting(); ConditionalFormattingRule conditionalFormattingRule = sheetConditionalFormatting .createConditionalFormattingRule("COUNTIF($A$2:$A$11,A2)>1"); FontFormatting fontFormatting = conditionalFormattingRule.createFontFormatting(); fontFormatting.setFontStyle(false, true); fontFormatting.setFontColorIndex(IndexedColors.BLUE.index); CellRangeAddress[] cellRangeAddresses = { CellRangeAddress.valueOf("A2:A11") }; sheetConditionalFormatting.addConditionalFormatting(cellRangeAddresses, conditionalFormattingRule); } static void shadeAlt(Sheet sheet) { SheetConditionalFormatting sheetConditionalFormatting = sheet.getSheetConditionalFormatting(); ConditionalFormattingRule conditionalFormattingRule = sheetConditionalFormatting .createConditionalFormattingRule("MOD(ROW(),2)"); PatternFormatting patternFormatting = conditionalFormattingRule.createPatternFormatting(); patternFormatting.setFillBackgroundColor(IndexedColors.LIGHT_GREEN.index); patternFormatting.setFillPattern(PatternFormatting.SOLID_FOREGROUND); CellRangeAddress[] cellRangeAddresses = { CellRangeAddress.valueOf("A1:Z100") }; sheetConditionalFormatting.addConditionalFormatting(cellRangeAddresses, conditionalFormattingRule); } static void expiryInNext30Days(Sheet sheet) { CellStyle cellStyle = sheet.getWorkbook().createCellStyle(); cellStyle.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(cellStyle); SheetConditionalFormatting sheetConditionalFormatting = sheet.getSheetConditionalFormatting(); ConditionalFormattingRule conditionalFormattingRule = sheetConditionalFormatting .createConditionalFormattingRule("AND(A2-TODAY()>=0,A2-TODAY()<=30)"); FontFormatting fontFormatting = conditionalFormattingRule.createFontFormatting(); fontFormatting.setFontStyle(false, true); fontFormatting.setFontColorIndex(IndexedColors.BLUE.index); CellRangeAddress[] cellRangeAddresses = { CellRangeAddress.valueOf("A2:A4") }; sheetConditionalFormatting.addConditionalFormatting(cellRangeAddresses, conditionalFormattingRule); sheet.getRow(0).createCell(1).setCellValue("The next 30 days are highlighted"); } }

Happy Exploring!