EasyExcel合并单元格（一）

前言

导出excel，介绍如何使用LoopMergeStrategy实现简单的合并

效果

每隔2行，合并一次

横向合并

横向和纵向合并

实现

导入依赖

 <!-- https://mvnrepository.com/artifact/com.alibaba/easyexcel -->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>easyexcel</artifactId>
            <version>2.2.7</version>
        </dependency>

        <!-- https://mvnrepository.com/artifact/com.google.guava/guava -->
        <dependency>
            <groupId>com.google.guava</groupId>
            <artifactId>guava</artifactId>
            <version>30.1-jre</version>
        </dependency>

        <!-- springboot test启动器 -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
        </dependency>

单元测试

/**
 * 合并单元格
 * @date 01/31/2021 03:11
 */
public class Demo {
    
    

    /**
     * 合并单元格
     */
    @Test
    public void testMyMergeWrite() {
    
    

        String fileName = "/Users/quanlinglong/Downloads/mergeDemo/" + "mymergeWrite" + System.currentTimeMillis() + ".xlsx";
        System.out.println("fileName = " + fileName);

        // 每隔2行合并一次，横向合并1列，从第0列开始
//        LoopMergeStrategy loopMergeStrategy = new LoopMergeStrategy(2, 1, 0);
        // 上面的等价于
//        LoopMergeStrategy loopMergeStrategy = new LoopMergeStrategy(2, 0);

        // 从第columnIndex列开始，向右合并（columnExtend-1）列
//        LoopMergeStrategy loopMergeStrategy = new LoopMergeStrategy(1, 2, 0);

        // 合并2行2列
        LoopMergeStrategy loopMergeStrategy = new LoopMergeStrategy(2, 2, 0);

        EasyExcel.write(fileName, WriteDemo.DemoData.class)
                .registerWriteHandler(loopMergeStrategy)
                .sheet("aaa")
                .doWrite(data());
    }

    private List<List<Object>> data() {
    
    
        List<List<Object>> result = new ArrayList<>();
        for (int i = 0; i < 3; i++) {
    
    
            result.add(Lists.newArrayList("标题" + i, new Date(), i * 0.1));
        }
        return result;
    }
}

分析LoopMergeStrategy类，它继承AbstractRowWriteHandler，在afterRowDispose方法里对每行做了处理，LoopMergeStrategy的构造函数传参是用来设置合并范围CellRangeAddress，再添加到当前sheet。

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

        }
    }

CellRangeAddress构造函数有4个参数
参数
0：合并起始行
1：合并终止行
2：合并起始列
3：合并终止列

 CellRangeAddress cellRangeAddress = new CellRangeAddress(row.getRowNum(), row.getRowNum() + this.eachRow - 1, this.columnIndex, this.columnIndex + this.columnExtend - 1);
 writeSheetHolder.getSheet().addMergedRegionUnsafe(cellRangeAddress);

构造函数传进来的eachRow, columnExtend, columnIndex，都用在这里了

相关链接
easyexcel 动态合并单元格