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Headers

This chapter introduces how to write header data in spreadsheet.

Complex Header Writing​

Overview​

Supports setting multi-level headers by specifying main titles and subtitles through the @ExcelProperty annotation.

POJO Class​


@Getter
@Setter
@EqualsAndHashCode
public class ComplexHeadData {
    @ExcelProperty({"主标题", "字符串标题"})
    private String string;
    @ExcelProperty({"主标题", "日期标题"})
    private Date date;
    @ExcelProperty({"主标题", "数字标题"})
    private Double doubleData;
}

Code Example​


@Test
public void complexHeadWrite() {
    String fileName = "complexHeadWrite" + System.currentTimeMillis() + ".xlsx";
    FesodSheet.write(fileName, ComplexHeadData.class)
            .sheet()
            .doWrite(data());
}

Result​

img

Dynamic Header Writing​

Overview​

Generate dynamic headers in real-time, suitable for scenarios where header content changes dynamically.

Code Example​


@Test
public void dynamicHeadWrite() {
    String fileName = "dynamicHeadWrite" + System.currentTimeMillis() + ".xlsx";

    List<List<String>> head = Arrays.asList(
            Collections.singletonList("动态字符串标题"),
            Collections.singletonList("动态数字标题"),
            Collections.singletonList("动态日期标题"));

    FesodSheet.write(fileName)
            .head(head)
            .sheet()
            .doWrite(data());
}

Result​

img

Header Merge Strategy​

Overview​

By default, FastExcel automatically merges header cells with the same name. However, you can control the merge behavior using the headerMergeStrategy parameter.

Merge Strategies​

  • NONE: No automatic merging is performed.
  • HORIZONTAL_ONLY: Only merges cells horizontally (same row).
  • VERTICAL_ONLY: Only merges cells vertically (same column).
  • FULL_RECTANGLE: Only merges complete rectangular regions where all cells have the same name.
  • AUTO: Automatic merging (default).

Code Example​

@Test
public void dynamicHeadWriteWithStrategy() {
    String fileName = "dynamicHeadWrite" + System.currentTimeMillis() + ".xlsx";

    List<List<String>> head = Arrays.asList(
        Collections.singletonList("动态字符串标题"),
        Collections.singletonList("动态数字标题"),
        Collections.singletonList("动态日期标题"));

    FastExcel.write(fileName)
        .head(head)
        .headerMergeStrategy(HeaderMergeStrategy.FULL_RECTANGLE)
        .sheet()
        .doWrite(data());
}

Common Use Cases​

Disable merging: Use NONE to completely disable automatic merging:

FastExcel.write(fileName)
    .head(head)
    .headerMergeStrategy(HeaderMergeStrategy.NONE)
    .sheet()
    .doWrite(data());

Note: The old automaticMergeHead parameter is still supported for backward compatibility. When headerMergeStrategy is not set, the behavior is determined by automaticMergeHead.