[Bug] Cannot add merged region xx to sheet because it overlaps with an existing merged region xx

[habyss]

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• I searched in the issues and found nothing similar.

Fastexcel version

1.3.0

JDK version

1.8

Operating system

win11

Minimal reproduce step

根据文档示例, 无法合并单元格

代码片段

        String fileName = "测试对齐报告_" + Instant.now().toEpochMilli() + ".xlsx";
        response.setCharacterEncoding("utf-8");
        response.setContentType("application/vnd.openxmlformats-officedocument.spreadsheetml.sheet");
        try {
            fileName = URLEncoder.encode(fileName, "UTF-8");
        } catch (UnsupportedEncodingException e) {
            log.error("编码异常", e);
            Assert.justFail("编码异常");
        }
        response.addHeader("Access-Control-Expose-Headers", "content-disposition");
        response.setHeader("content-disposition", "attachment;fileName=" + fileName);
        try {
            FastExcel.write(response.getOutputStream())
                    .registerWriteHandler(new AbstractMergeStrategy() {
                        @Override
                        protected void merge(Sheet sheet, Cell cell, Head head, Integer integer) {
                            // Custom merge rules
                            sheet.addMergedRegion(new CellRangeAddress(3, 4, 3, 4));
                        }
                    })
                    .sheet("测试")
                    .doWrite(Arrays.asList(Arrays.asList(1, 1, 1, 1, 1, 1),
                            Arrays.asList(1, 1, 1, 1, 1, 1),
                            Arrays.asList(1, 1, 1, 1, 1, 1),
                            Arrays.asList(1, 1, 1, 1, 1, 1),
                            Arrays.asList(1, 1, 1, 1, 1, 1)));
        } catch (IOException e) {
            throw new RuntimeException(e);
        }

结果:
Cannot add merged region D4:E5 to sheet because it overlaps with an existing merged region (D4:E5).

                        @Override
                        protected void merge(Sheet sheet, Cell cell, Head head, Integer integer) {
                            // Custom merge rules
                            sheet.addMergedRegion(new CellRangeAddress(3, 4, 3, 4));
                        }

不论这里面写什么单元格, 都会报相应的错误, 总之就是不能合并

如果使用addMergedRegionUnsafe则可以成功合并, 但是打开文件时会出现文件修复选项, 不可取

What did you expect to see?

成功合并单元格

What did you see instead?

如果不能很快解决的话, 有没有什么替代方案实现这个功能

ps: 合并的单元格是不固定的, 自定义的, 需要业务代码来动态生成, 所以需要灵活, 非注解类型

Anything else?

No response

Are you willing to submit a PR?

• I'm willing to submit a PR!

[habyss]

找到原因了, 是因为这块代码每行每列都会被执行一次

 @Override
                        protected void merge(Sheet sheet, Cell cell, Head head, Integer integer) {
                            // Custom merge rules
                            sheet.addMergedRegion(new CellRangeAddress(3, 4, 3, 4));
                        }

导致了重复merge, 加了个标识进行标记, 让它只被执行一次就可以了

public class CustomMergeStrategy extends AbstractMergeStrategy {

    private AtomicBoolean atomicBoolean;

    public CustomMergeStrategy(AtomicBoolean atomicBoolean){
        this.atomicBoolean = atomicBoolean;
    }

    @Override
    protected void merge(Sheet sheet, Cell cell, Head head, Integer integer) {
        // Custom merge rules
        if (atomicBoolean.get()) {
            sheet.addMergedRegion(new CellRangeAddress(3, 4, 3, 4));
            sheet.addMergedRegion(new CellRangeAddress(1, 2, 1, 2));
            atomicBoolean.set(false);
        }
    }
}

public void export(HttpServletResponse response) {

        String fileName = "测试对齐报告_" + Instant.now().toEpochMilli() + ".xlsx";
        response.setCharacterEncoding("utf-8");
        response.setContentType("application/vnd.openxmlformats-officedocument.spreadsheetml.sheet");
        try {
            fileName = URLEncoder.encode(fileName, "UTF-8");
        } catch (UnsupportedEncodingException e) {
            log.error("编码异常", e);
            Assert.justFail("编码异常");
        }
        response.addHeader("Access-Control-Expose-Headers", "content-disposition");
        response.setHeader("content-disposition", "attachment;fileName=" + fileName);
        AtomicBoolean atomicBoolean = new AtomicBoolean(true);
        try {
            FastExcel.write(response.getOutputStream())
                    .registerWriteHandler(new CustomMergeStrategy(atomicBoolean))
                    .sheet("测试")
                    .doWrite(Arrays.asList(Arrays.asList(1, 1, 1, 1, 1, 1),
                            Arrays.asList(1, 1, 1, 1, 1, 1),
                            Arrays.asList(1, 1, 1, 1, 1, 1),
                            Arrays.asList(1, 1, 1, 1, 1, 1),
                            Arrays.asList(1, 1, 1, 1, 1, 1)));
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
    }

但原来的文档还是挺容易被误导的...

[alaahong]

How about raise a PR to update the doc content as your finding?