easyExcel单元格动态合并示例

1.先按照mergekey排序，然后相同的key分组，只保留第一个对象，其他对象属性都设置为null.2.

ClassPathResource resource = new ClassPathResource("template/template.xlsx");
ExcelWriter excelWriter = EasyExcel.write(outputStream).withTemplate(resource.getInputStream()).build();
WriteSheet writeSheet = EasyExcel.writerSheet().registerWriteHandler(new PartBoxMergeStrategyNew(16, 27, 11, details.size())).build();FillConfig fillConfig = FillConfig.builder().forceNewRow(Boolean.TRUE).build();
excelWriter.fill(header, writeSheet);
excelWriter.fill(details, fillConfig, writeSheet);
excelWriter.finish();

3.public class PartBoxMergeStrategyNew implements CellWriteHandler {// 需要合并的起始列索引（从0开始）private final int startMergeColumns;// 需要合并的结束列索引（从0开始）private final int endMergeColumns;// rowIndex 从0 开始private final int startMergeRowIndex;// rowIndex 从0 开始sprivate final int lastRowIndex;public PartBoxMergeStrategyNew(int startMergeColumns, int endMergeColumns, int startMergeRowIndex, int rowSize) {this.startMergeColumns = startMergeColumns;this.endMergeColumns = endMergeColumns;this.startMergeRowIndex = startMergeRowIndex;this.lastRowIndex = rowSize-1+startMergeRowIndex;}@Overridepublic void afterCellDispose(WriteSheetHolder writeSheetHolder, WriteTableHolder writeTableHolder, List<WriteCellData<?>> cellDataList, Cell cell, Head head, Integer relativeRowIndex, Boolean isHead) {// 跳过表头和空值单元格if (isHead) return;Sheet sheet = writeSheetHolder.getSheet();int col = cell.getColumnIndex();int rowIndex = cell.getRowIndex();boolean lastFlag = rowIndex == lastRowIndex;if(rowIndex <= startMergeRowIndex) return;if (col >= startMergeColumns && col <= endMergeColumns) {mergeAdjacentCells(sheet, cell, rowIndex, col, lastFlag);}}//row是从0开始的private void mergeAdjacentCells(Sheet sheet, Cell cell, int currentRowIndex, int currentColIndex, boolean lastFlag) {int firstRow = currentRowIndex;int lastRow = currentRowIndex;// 向上查找合并起始行（跳过空值）// 这里是要等到最后一个空值才进行合并Cell curr = cell.getSheet().getRow(currentRowIndex).getCell(startMergeColumns);while (firstRow -1 >= startMergeRowIndex) {Cell prev = cell.getSheet().getRow(firstRow -1).getCell(startMergeColumns);if(lastFlag) {if(getCellValue(curr)==null&&getCellValue(prev)==null) {//最后一行，当前为空，前一个为空，则继续找，说明还没有找到最前面的一行不为空的，需要继续firstRow--;}else if(getCellValue(curr)==null&&getCellValue(prev)!=null){//最后一行，当前为空，前一个不为空，说明已经找到了需要合并的最前面的一行，同时当前也是空的，所以lastRow不用-1firstRow--;break;}else if(getCellValue(curr)!=null&&getCellValue(prev)!=null){//最后一行，当前不为空，前一个也不为空，相邻的两行都不是空的，无需合并lastRow--;                     break;}else{//最后一行，当前不为空，前一个为空，当前不为空，则说明当前行不是一伙的，所以要-1,前一行为空，说明这一行的领头羊在前面firstRow--;}}else{if(getCellValue(curr)==null) {//不是最后一行，当前为空,则需要等到不为空的行再往上面找,不需要触发合并，break;}else{if(getCellValue(prev)==null){//不是最后一行，当前不为空，前一个为空，则继续找firstRow--;}else{//不是最后一行，当前不为空，前一个不为空，则不用找，当前不为空，说明跟前面不是一伙的，// 前一个不为空，则说明已经找到了最前面的领头的firstRow--;lastRow--;break;}}}}// cur=17 16// 执行合并（如果跨越多行）if (lastRow > firstRow) {sheet.addMergedRegionUnsafe(new CellRangeAddress(firstRow , lastRow , currentColIndex, currentColIndex));}}private Object getCellValue(Cell cell) {switch (cell.getCellType()) {case STRING:return cell.getStringCellValue();case NUMERIC:return cell.getNumericCellValue();case BOOLEAN:return cell.getBooleanCellValue();default:return null;}}}