easyexcel导出中自定义合并单元格,通过重写AbstractRowWriteHandler

news2024/9/29 19:16:55

针对阿里的easyexcel 自定义处理任意单元格合并

官方给出的合并单元格只给出固定规律的单元格合并,当然官方也指出可以自定义合并单元格的策略,我们跟进LoopMergeStrategy 这个合并策略的实例类,发现里面继承了AbstractRowWriteHandler,官方示例代码如下

   /**
     * 合并单元格
     * <p>
     * 1. 创建excel对应的实体对象 参照{@link DemoData} {@link DemoMergeData}
     * <p>
     * 2. 创建一个merge策略 并注册
     * <p>
     * 3. 直接写即可
     *
     * @since 2.2.0-beta1
     */
    @Test
    public void mergeWrite() {
        // 方法1 注解
        String fileName = TestFileUtil.getPath() + "mergeWrite" + System.currentTimeMillis() + ".xlsx";
        // 在DemoStyleData里面加上ContentLoopMerge注解
        // 这里 需要指定写用哪个class去写，然后写到第一个sheet，名字为模板 然后文件流会自动关闭
        EasyExcel.write(fileName, DemoMergeData.class).sheet("模板").doWrite(data());

        // 方法2 自定义合并单元格策略
        fileName = TestFileUtil.getPath() + "mergeWrite" + System.currentTimeMillis() + ".xlsx";
        // 每隔2行会合并 把eachColumn 设置成 3 也就是我们数据的长度，所以就第一列会合并。
        //当然其他合并策略也可以自己写
        LoopMergeStrategy loopMergeStrategy = new LoopMergeStrategy(2, 0);
        // 这里 需要指定写用哪个class去写，然后写到第一个sheet，名字为模板 然后文件流会自动关闭
        EasyExcel.write(fileName, DemoData.class).registerWriteHandler(loopMergeStrategy).sheet("模板").doWrite(data());
    }

LoopMergeStrategy 的具体实现

/**
 * The regions of the loop merge
 *
 * @author Jiaju Zhuang
 */
public class LoopMergeStrategy extends AbstractRowWriteHandler {
    /**
     * Each row
     */
    private int eachRow;
    /**
     * Extend column
     */
    private int columnExtend;
    /**
     * The number of the current column
     */
    private int columnIndex;

    public LoopMergeStrategy(int eachRow, int columnIndex) {
        this(eachRow, 1, columnIndex);
    }

    public LoopMergeStrategy(int eachRow, int columnExtend, int columnIndex) {
        if (eachRow < 1) {
            throw new IllegalArgumentException("EachRows must be greater than 1");
        }
        if (columnExtend < 1) {
            throw new IllegalArgumentException("ColumnExtend must be greater than 1");
        }
        if (columnExtend == 1 && eachRow == 1) {
            throw new IllegalArgumentException("ColumnExtend or eachRows must be greater than 1");
        }
        if (columnIndex < 0) {
            throw new IllegalArgumentException("ColumnIndex must be greater than 0");
        }
        this.eachRow = eachRow;
        this.columnExtend = columnExtend;
        this.columnIndex = columnIndex;
    }

    public LoopMergeStrategy(LoopMergeProperty loopMergeProperty, Integer columnIndex) {
        this(loopMergeProperty.getEachRow(), loopMergeProperty.getColumnExtend(), columnIndex);
    }

    @Override
    public void afterRowDispose(WriteSheetHolder writeSheetHolder, WriteTableHolder writeTableHolder, Row row,
        Integer relativeRowIndex, Boolean isHead) {
        if (isHead) {
            return;
        }
        if (relativeRowIndex % eachRow == 0) {
            CellRangeAddress cellRangeAddress = new CellRangeAddress(row.getRowNum(), row.getRowNum() + eachRow - 1,
                columnIndex, columnIndex + columnExtend - 1);
            writeSheetHolder.getSheet().addMergedRegionUnsafe(cellRangeAddress);
        }
    }

}

我们根据官方给出的AbstractRowWriteHandler行处理类重写:

1.引入jar包

<dependency>

<groupId>com.alibaba</groupId>

<artifactId>easyexcel</artifactId>

<version>2.2.3</version>

</dependency>

2.声明需要合并单元格的定位实例

/**
 * easyExcel 单元格范围设定
 */
@Data
@AllArgsConstructor
public class ExcelCellRange{
    /**
     * 起始行
     */
    private int firstRow;
    /**
     * 终止行
     */
    private int lastRow;
    /**
     * 起始列
     */
    private int firstCol;
    /**
     * 终止列
     */
    private int lastCol;

}

3.重写自定义合并策略类

/**
 * @Description:EasyExcel自定义合并单元格策略
 * @Date: 2023/4/14 16:11
 */
public class EasyExcelCustomMergeStrategy extends AbstractRowWriteHandler {
    /**
     * 单元格范围
     */
    private List<ExcelCellRange> cellRanges;

    public EasyExcelCustomMergeStrategy(List<ExcelCellRange> cellRanges) {
        this.cellRanges = cellRanges;
    }

    @Override
    public void afterRowDispose(WriteSheetHolder writeSheetHolder, WriteTableHolder writeTableHolder, Row row, Integer relativeRowIndex, Boolean isHead) {
        if (!isHead) {
            for(ExcelCellRange cellRange :cellRanges)
            {
                if (relativeRowIndex % cellRange.getFirstRow() == 0) {
                    CellRangeAddress cellRangeAddress = new CellRangeAddress(cellRange.getFirstRow(), cellRange.getLastRow(), cellRange.getFirstCol(), cellRange.getLastCol());
                    writeSheetHolder.getSheet().addMergedRegionUnsafe(cellRangeAddress);
                }
            }


        }
    }

}

以上封装的实例 ,仅供参考,大家可以自行完善参数校验等逻辑

4.使用案例

// 定位合并数据
int rowIndex = 1;  // 从第二行开始，因为第一行是表头
//存放合并单元格位置
List<ExcelCellRange> cellRanges = Lists.newArrayListWithCapacity(5);
            cellRanges.add(new ExcelCellRange(0, 1, 0, 0));
            cellRanges.add(new ExcelCellRange(0, 1, 1, 1));
            cellRanges.add(new ExcelCellRange(0, 1, 2, 2));
        
//合并策略
EasyExcelCustomMergeStrategy mergeStrategy = new EasyExcelCustomMergeStrategy(cellRanges);
// 创建工作簿并指定写入的Excel文件
ExcelWriter excelWriter = EasyExcel.write(os)
        .head(TtRoomCheckInStateRes.class)
        .registerWriteHandler(mergeStrategy)
        .build();
// 创建一个只包含一行的Excel表格，用于合并单元格及为表格添加表头
WriteSheet writeSheet = EasyExcel.writerSheet(0, "房间入住情况").build();
//信息写入
excelWriter.write(roomRecordList, writeSheet);
//关闭流
excelWriter.finish();