1.项目场景：
简介：报销单导出要根据指定的excel模板去自动替换对应，然后重新生成一份新的excel。在给定的excel模板中，有部分字段进行了单元格合并，如下所示。
2.问题描述
由于一张报销单可能存在多条报销内容，可以看到，当超过模板中预先给定的一条时，则会自动换行，但换行时并不会自动依照模板中的样式进行单元格合并，如下所示。
3.原因分析：
首先可以直观的看到excel进行数据插入并自动换行的时候，换行的数据并没有按照上一行的样式进行自动合并。
于是便想着用代码把这几列手动合并，然后再加上边框样式就可以解决了。
4.解决方案：
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需要注意的是，按照以上的思路，直接进行单元格合并，然后加上边框并不能直接解决问题。
需要将后边空的每一个单元格先创建出来，然后将其一块合并才可以解决，创建单元格代码在下方
CustomCellWriteHandler类中说明。
这也算是耗费一整天时间踩的坑。。。
public static void outExcelBalance(String modelFile, String newFile, Map<String, Object> map, List<FillDataExpense> fillData, HttpServletResponse response, String fileName){
//定义model模板中默认的行数
int firstRow = 7; //excel中表示第八行，即模板中默认的一条
int lastRow = 7;
InputStream is = null;
File file = new File(modelFile);
File file1 = new File(newFile);
//String file1Name = file1.getName();
BufferedInputStream bis = null;
try {
if (!file.exists()) {
copyFileUsingJava7Files(file, file1);
}
//TODO 单元格样式
Set<Integer> rowsBorderSet= new HashSet<>();
CustomCellWriteHandler customCellWriteHandler = null;
//TODO 单元格合并
List<CellRangeAddress> cellRangeAddresss = new ArrayList<>();
if (ListUtils.isNotNull(fillData)){
if (fillData.size() > 1){
//合并每条报销单的第3-10列
for (int i = 1; i < fillData.size(); i++) {
firstRow++;
lastRow++;
cellRangeAddresss.add(new CellRangeAddress(firstRow, lastRow, 2, 9));
cellRangeAddresss.add(new CellRangeAddress(firstRow, lastRow, 10, 11));
rowsBorderSet.add(firstRow);
}
}
}
customCellWriteHandler = new CustomCellWriteHandler(rowsBorderSet);
MyMergeStrategy myMergeStrategy = new MyMergeStrategy(cellRangeAddresss);
ExcelWriter excelWriter = EasyExcel.write(newFile)
//注册单元格式
.registerWriteHandler(customCellWriteHandler)
//注册合并策略
.registerWriteHandler(myMergeStrategy)
.withTemplate(modelFile).build();
WriteSheet writeSheet = EasyExcel.writerSheet().build();
FillConfig fillConfig = FillConfig.builder().forceNewRow(Boolean.TRUE).build();
if (!ListUtil.listIsEmpty(fillData)){
excelWriter.fill(fillData, fillConfig, writeSheet);
//excelWriter.fill(fillData, fillConfig, writeSheet);
}
excelWriter.fill(map, writeSheet);
excelWriter.finish();
response.setHeader("content-type", "text/plain");
response.setHeader("content-type", "application/x-msdownload;");
response.setContentType("text/plain; charset=utf-8");
response.setHeader("Content-Disposition", "attachment; filename=" + new String(fileName.getBytes("utf-8"),"ISO8859-1"));
byte[] buff = new byte[1024];
OutputStream os = null;
os = response.getOutputStream();
bis = new BufferedInputStream(new FileInputStream(file1));
int i = bis.read(buff);
while (i != -1) {
os.write(buff, 0, buff.length);
os.flush();
i = bis.read(buff);
}
}
catch (Exception e){
LOGGER.error(e.getMessage());
}
finally {
if (bis != null) {
try {
bis.close();
} catch (IOException e) {
e.printStackTrace();
}
}
// 删除生成文件
/*if (file1.exists()) {
file1.delete();
}*/
}
}单元格合并MyMergeStrategy类代码：
public class MyMergeStrategy extends AbstractMergeStrategy {
//合并坐标集合
private List<CellRangeAddress> cellRangeAddresss;
//构造
public MyMergeStrategy(List<CellRangeAddress> cellRangeAddresss) {
this.cellRangeAddresss = cellRangeAddresss;
}
@Override
protected void merge(Sheet sheet, Cell cell, Head head, Integer integer) {
if (ListUtils.isNotNull(cellRangeAddresss)) {
if (cell.getRowIndex() == 7 ) {
for (CellRangeAddress item : cellRangeAddresss) {
sheet.addMergedRegionUnsafe(item);
}
}
}
}
}单元格样式CustomCellWriteHandler类代码：
public class CustomCellWriteHandler implements CellWriteHandler {
private static final Logger LOGGER = LoggerFactory.getLogger(CustomCellWriteHandler.class);
//标黄行宽集合
private Set<Integer> rowIndexs;
//构造
public CustomCellWriteHandler(Set<Integer> rowIndexs) {
this.rowIndexs = rowIndexs;
}
public CustomCellWriteHandler() {
}
@Override
public void beforeCellCreate(WriteSheetHolder writeSheetHolder, WriteTableHolder writeTableHolder, Row row, Head head, Integer columnIndex, Integer relativeRowIndex, Boolean isHead) {
LOGGER.info("beforeCellCreate~~~~");
}
@Override
public void afterCellCreate(WriteSheetHolder writeSheetHolder, WriteTableHolder writeTableHolder, Cell cell, Head head, Integer relativeRowIndex, Boolean isHead) {
LOGGER.info("afterCellCreate~~~~");
}
@Override
public void afterCellDataConverted(WriteSheetHolder writeSheetHolder, WriteTableHolder writeTableHolder, CellData cellData, Cell cell, Head head, Integer integer, Boolean aBoolean) {
}
@Override
public void afterCellDispose(WriteSheetHolder writeSheetHolder, WriteTableHolder writeTableHolder, List<CellData> cellDataList, Cell cell, Head head, Integer relativeRowIndex, Boolean isHead) {
//获取工作簿
// HSSFWorkbook wb = new HSSFWorkbook();
// //获取sheet
// HSSFSheet sheet = wb.createSheet();
// HSSFRow row = sheet.createRow();
// HSSFCellStyle style = wb.createCellStyle();
// 这里可以对cell进行任何操作
if (CollectionUtils.isNotEmpty(rowIndexs)) {
Workbook workbook = writeSheetHolder.getSheet().getWorkbook();
CellStyle cellStyle = workbook.createCellStyle();
Sheet sheet = writeSheetHolder.getSheet();
cellStyle.setAlignment(new HSSFWorkbook().createCellStyle().getAlignment());
cellStyle.setBorderBottom(BorderStyle.THIN); //下边框
cellStyle.setBottomBorderColor(IndexedColors.BLACK.getIndex());
cellStyle.setBorderLeft(BorderStyle.THIN);//左边框
cellStyle.setBorderTop(BorderStyle.THIN);//上边框
cellStyle.setBorderRight(BorderStyle.THIN);//右边框
cellStyle.setWrapText(true);//自动换行
//字体
// Font cellFont = workbook.createFont();
// cellFont.setBold(true);
// cellStyle.setFont(cellFont);
// //标黄,要一起设置
// cellStyle.setFillPattern(FillPatternType.SOLID_FOREGROUND); //设置前景填充样式
// cellStyle.setFillForegroundColor(IndexedColors.YELLOW.getIndex());//前景填充色
if (rowIndexs.contains(cell.getRowIndex())) {
Row row = null;
//循环创建空白单元格
for (int i = 0; i < rowIndexs.size(); i++) {
for (Integer rowIndex : rowIndexs){
//创建4-10列的空白格
row = sheet.getRow(rowIndex.intValue());
if (row == null){
row = sheet.createRow(rowIndex.intValue());
}
for (int j = 3; j <= 9; j++) {
//获取8行的cell列
cell = row.createCell(j);
cell.setCellStyle(cellStyle);
cell.setCellValue(" ");
LOGGER.info("第{}行，第{}列创建空白格。", cell.getRowIndex(), j);
}
//创建12列的红白格
cell = row.createCell(11);
cell.setCellStyle(cellStyle);
cell.setCellValue(" ");
LOGGER.info("第{}行，第11列创建空白格。", cell.getRowIndex());
//创建21列的空白格
cell = row.createCell(21);
cell.setCellStyle(cellStyle);
cell.setCellValue(" ");
LOGGER.info("第{}行，第21列创建空白格。", cell.getRowIndex());
}
}
}
}
}
}5.总结
核心步骤：
1.
//创建单元格样式
CustomCellWriteHandler customCellWriteHandler = new CustomCellWriteHandler(参数按需给定);
2.
//单元格进行合并
List<CellRangeAddress> cellRangeAddresss = new ArrayList<>();
//例如：从firstRow行到lastRow行的2列到9列合并
cellRangeAddresss.add(new CellRangeAddress(firstRow, lastRow, 2, 9));
cellRangeAddresss.add(new CellRangeAddress(firstRow, lastRow, 10, 11));
MyMergeStrategy myMergeStrategy = new MyMergeStrategy(cellRangeAddresss);
3.
//注册以上两种策略
ExcelWriter excelWriter = EasyExcel.write(newFile)
//注册单元格式
.registerWriteHandler(customCellWriteHandler)
//注册合并策略
.registerWriteHandler(myMergeStrategy)
.withTemplate(modelFile).build();说明：刚开始修复的时候，并没有想过后边每个空的单元格需要先创建出来，才可以进行合并。一直以为是工具类的问题，后来不断的翻阅解决方案，看到有说需要先进行创建空白单元格，然后再进行合并，最终完美解决了。
关于代码部分，由于是业务代码，中间夹杂了许多不需要的。
