1. 合并单元格概述

合并单元格CellRangeAddress就是将几个相邻的单元格合并为一个单元格，即使没有创建过行和单元格，也 可以创建合并单元格，因为单元格信息是单独存储的

/** * Creates new cell range. base 0 * * @param firstRow Index of first row * @param lastRow Index of last row (inclusive), must be equal to or larger than {@code firstRow} * @param firstCol Index of first column * @param lastCol Index of last column (inclusive), must be equal to or larger than {@code firstCol} */
    public CellRangeAddress(int firstRow, int lastRow, int firstCol, int lastCol)

2. 创建合并单元格

创建合并单元格很简单：

1. 创建一个合并单元格region
 2. 将region添加到工作表Sheet中

CellRangeAddress region  = new CellRangeAddress(firstRow, lastRow, firstCol, lastCol);
CellRangeAddress region  = new CellRangeAddress("A1:E10");
sheet.addMergedRegion(region)

3. 合并单元格内容

合并单元格的内容需要通过设置合并区域左上角单元格的内容确定，设置合并区域内其他单元格是不起效的
上图中需要设置A1单元格内容才是设置合并的那远哥的内容

Cell cell = sheet.createRow(0).createCell(0);
cell.setCellValue("合并单元格");

4. 实例

package hssf.sheet.cell;

import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileOutputStream;

import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.hssf.usermodel.HSSFSheet;
import org.apache.poi.hssf.usermodel.HSSFCell;
import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.HorizontalAlignment;
import org.apache.poi.ss.usermodel.Sheet;
import org.apache.poi.ss.usermodel.VerticalAlignment;
import org.apache.poi.ss.usermodel.BorderStyle;
import org.apache.poi.ss.usermodel.IndexedColors;
import org.apache.poi.ss.usermodel.Workbook;
import org.apache.poi.ss.util.CellRangeAddress;
import org.apache.poi.ss.util.CellUtil;
import org.apache.poi.ss.util.RegionUtil;
import org.apache.poi.ss.util.WorkbookUtil;

/** * 合并单元格 * 1.创建一个合并单元格 * 2.设置合并单元格内容 * 3.设置合并单元格边框样式 * */
public class ExportRegionCell {
    public static void main(String[] args) throws Exception {
        File file = new File("C:\\Users\\Administrator\\Desktop\\test.xls");
        if (file.exists()) {
            file.delete();
        }
        BufferedOutputStream out = null;
        try {
            out = new BufferedOutputStream(new FileOutputStream("C:\\Users\\Administrator\\Desktop\\test.xls"));
            exportExcel(out);
        } finally {
            out.close();
        }
    }

    private static void exportExcel(BufferedOutputStream out) throws Exception {
        Workbook workbook = new HSSFWorkbook();
//      Workbook workbook = new XSSFWorkbook();
        String safeSheetName = WorkbookUtil.createSafeSheetName("合并单元格");
        Sheet sheet = workbook.createSheet(safeSheetName);

        // 1.创建一个合并单元格
//      CellRangeAddress region = new CellRangeAddress(0, 9, 0, 4);
        CellRangeAddress region = CellRangeAddress.valueOf("A1:E10");
        sheet.addMergedRegion(region);

        // 2.设置合并单元格内容
        Cell cell = sheet.createRow(0).createCell(0);
        cell.setCellValue("合并单元格");

        // 设置单元格内容水平垂直居中
        CellUtil.setAlignment(cell, HorizontalAlignment.CENTER);
        CellUtil.setVerticalAlignment(cell, VerticalAlignment.CENTER);

        // 3.设置合并单元格边框
        setBorderStyle(sheet, region);

        workbook.write(out);
    }

    /** * 设置合并单元格边框 - 线条 * */
    private static void setBorderStyle(Sheet sheet, CellRangeAddress region) {
        // 合并单元格左边框样式
        RegionUtil.setBorderLeft(BorderStyle.THICK, region, sheet);
        RegionUtil.setLeftBorderColor(IndexedColors.LIGHT_BLUE.getIndex(), region, sheet);

        // 合并单元格上边框样式
        RegionUtil.setBorderTop(BorderStyle.THICK, region, sheet);
        RegionUtil.setTopBorderColor(IndexedColors.LIGHT_ORANGE.getIndex(), region, sheet);

        // 合并单元格右边框样式
        RegionUtil.setBorderRight(BorderStyle.THICK, region, sheet);
        RegionUtil.setRightBorderColor(IndexedColors.LIGHT_BLUE.getIndex(), region, sheet);

        // 合并单元格下边框样式
        RegionUtil.setBorderBottom(BorderStyle.THICK, region, sheet);
        RegionUtil.setBottomBorderColor(IndexedColors.LIGHT_ORANGE.getIndex(), region, sheet);
    }
}

截图：