import org.apache.poi.ss.usermodel.Sheet;
import org.apache.poi.ss.usermodel.Workbook;
import org.apache.poi.ss.util.CellRangeAddress;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;import java.io.*;
import java.util.*;public class MyExcelUtils {private static final String seperator = UUID.randomUUID().toString().replaceAll( "-","" );public static void main(String[] args) throws IOException {List<Integer> colIndexs = new ArrayList<>();colIndexs.add( 0 );colIndexs.add( 1 );colIndexs.add( 2 );String inputPath = "D:\\xxx\\test.xlsx";String outputPath = "D:\\xxx\\output.xlsx";doRowMerge( colIndexs,inputPath,outputPath );}/** ps： Workbook 中 excel 的第一行的 rowIndex = 0，第一列的 colIndex = 0* 对指定 excel 的指定列进行行合并( 按照从做到右的树形行合并 )* @param colIndexList_needRowMerge* @param inputExcelPath* @param outputExcelPath*/public static void doRowMerge( List<Integer> colIndexList_needRowMerge,String inputExcelPath,String outputExcelPath ) throws IOException {// 校验：colIndexList_needRowMerge 中不能出现重复 的 colIndexif( new HashSet<Integer>( colIndexList_needRowMerge ).size() < colIndexList_needRowMerge.size() ){throw new RuntimeException( "操作失败，There are duplicate elements in the list colIndexList_needRowMerge" );}// 对 colIndexList_needRowMerge 中的 colIndex 排序(从小到大)Collections.sort( colIndexList_needRowMerge );if( colIndexList_needRowMerge == null || colIndexList_needRowMerge.size() == 0 ){return;}inputExcelPath = MyStringUtils.null2EmptyWithTrim( inputExcelPath );outputExcelPath = MyStringUtils.null2EmptyWithTrim( outputExcelPath );if( inputExcelPath.length() == 0 || outputExcelPath.length() == 0 ){return;}// 对临时 excel 进行行合并Workbook workbook = null;try {workbook = new XSSFWorkbook( new FileInputStream( new File( inputExcelPath ) ) );Sheet sheet = workbook.getSheetAt(0);int lastRowIndex = sheet.getLastRowNum();for( Integer colIndex:colIndexList_needRowMerge ){int startRowIndex = 0;int endRowIndex = startRowIndex;String cellContent_prevRow = getCellContent_withPrevCols( sheet,0,colIndex,colIndexList_needRowMerge );System.out.println( cellContent_prevRow );for (int rowIndex = 1; rowIndex <= lastRowIndex; rowIndex++) {String cellContent_currRow = getCellContent_withPrevCols( sheet,rowIndex,colIndex,colIndexList_needRowMerge );if( cellContent_currRow.equals( cellContent_prevRow ) ){endRowIndex++;}else {if( ( endRowIndex - startRowIndex ) >= 1 ){sheet.addMergedRegion( new CellRangeAddress( startRowIndex, endRowIndex, colIndex, colIndex ) );System.out.println( "合并第" + colIndex + "列的 " + startRowIndex + "行~" + endRowIndex + "行" );}startRowIndex = endRowIndex + 1;endRowIndex = startRowIndex;cellContent_prevRow = cellContent_currRow;}}System.out.println( "startRowIndex = " + startRowIndex );System.out.println( "endRowIndex = " + endRowIndex );if( ( endRowIndex - startRowIndex ) >= 1 ){sheet.addMergedRegion( new CellRangeAddress( startRowIndex, endRowIndex, colIndex, colIndex ) );System.out.println( "合并第" + colIndex + "列的 " + startRowIndex + "行~" + endRowIndex + "行" );}}workbook.write( new FileOutputStream( new File( outputExcelPath )) );System.out.println("Cells merged successfully!");} catch (IOException e) {e.printStackTrace();}finally {if( workbook != null ){workbook.close();}}}private static String getCellContent_withPrevCols(Sheet sheet, int rowIndex,int colIndex,List<Integer> colIndexList_needRowMerge ) {String cellContent = "";for( Integer colIndex_:colIndexList_needRowMerge ){if( colIndex_ <= colIndex ){cellContent += sheet.getRow( rowIndex ).getCell( colIndex_ ).getStringCellValue();cellContent += seperator;}else {break;}}return cellContent;}
}
示例：
1. 原始 excel：
2. 对前三列进行合并后的 excel： 