1、 Maven仓库下载导入

在pom.xml中配置maven路径，指定依赖，如下：

<dependency>
<groupId>org.apache.poi</groupId>
<artifactId>poi</artifactId>
<version>4.1.1</version>
</dependency>
<dependency>
<groupId>org.apache.poi</groupId>
<artifactId>poi-ooxml</artifactId>
<version>4.1.1</version>
</dependency>

2、写入

2.1 数据格式

要把每个单元格信息（包含：位置、值等）都一一列举清楚，

需要的字段：

位置：firstRow，lastRow，firstCol，lastCol；(从0开始)

值：value；

[{"firstRow":0,"lastRow":6,"lastCol":0,"firstCol":0,"value":"秦时明月汉时关"},{"firstRow":0,"lastRow":0,"lastCol":1,"firstCol":1,"value":"万"},{"firstRow":1,"lastRow":1,"lastCol":1,"firstCol":1,"value":"里"},{"firstRow":2,"lastRow":2,"lastCol":1,"firstCol":1,"value":"长"},{"firstRow":3,"lastRow":3,"lastCol":1,"firstCol":1,"value":"征"},{"firstRow":4,"lastRow":4,"lastCol":1,"firstCol":1,"value":"人"},{"firstRow":5,"lastRow":5,"lastCol":1,"firstCol":1,"value":"未"},{"firstRow":6,"lastRow":6,"lastCol":1,"firstCol":1,"value":"还"},{"firstRow":3,"lastRow":3,"lastCol":2,"firstCol":2,"value":"但使龙城飞将在"},{"firstRow":0,"lastRow":0,"lastCol":3,"firstCol":3,"value":"不"},{"firstRow":1,"lastRow":1,"lastCol":3,"firstCol":3,"value":"教"},{"firstRow":2,"lastRow":2,"lastCol":3,"firstCol":3,"value":"胡"},{"firstRow":3,"lastRow":3,"lastCol":3,"firstCol":3,"value":"马"},{"firstRow":4,"lastRow":4,"lastCol":3,"firstCol":3,"value":"度"},{"firstRow":5,"lastRow":5,"lastCol":3,"firstCol":3,"value":"阴"},{"firstRow":6,"lastRow":6,"lastCol":3,"firstCol":3,"value":"山"}]

2.2 代码

package com;import com.alibaba.fastjson.JSONObject;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.ss.usermodel.*;
import org.apache.poi.ss.util.CellRangeAddress;
import org.apache.poi.xssf.streaming.SXSSFWorkbook;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;import java.io.FileOutputStream;
import java.io.IOException;
import java.util.List;public class ExcelTest {/*** 写入excel数据** @param path    excel保存路径* @param name    excel名称* @param version excel格式，支持xls、xlsx* @param rows    excel单元格信息（包含位置、值等信息,rows中每个Json必须包含位置和值的信息，*                位置:firstRow，lastRow，firstCol，lastCol，值:value）*/public static void writeMergeExcel(String path, String name, String version,List<JSONObject> rows) {try {Workbook wb = produce(version);createSheet(wb, name, version, rows,null);String filePath = path + name;if (!filePath.endsWith(version)) {filePath = filePath +"."+ version;}FileOutputStream fileOut = new FileOutputStream(filePath);wb.write(fileOut);fileOut.close();} catch (Exception e) {e.printStackTrace();}}/*** 写入excel数据** @param path    excel保存路径* @param name    excel名称* @param version excel格式，支持xls、xlsx* @param rows    excel单元格信息（包含位置、值等信息）* @param rowKeys excel单元格字段信息（rows中每个Json必须包含位置和值的信息，如果存储的字段与工具中的字段不一致，做个映射，工具中的字段：:firstRow，lastRow，firstCol，lastCol，值:value）*/public static void writeMergeExcel(String path, String name, String version,List<JSONObject> rows, JSONObject rowKeys) {try {Workbook wb = produce(version);createSheet(wb, name, version, rows,  rowKeys);String filePath = path + name;if (!filePath.endsWith(version)) {filePath = filePath +"."+ version;}FileOutputStream fileOut = new FileOutputStream(filePath);wb.write(fileOut);fileOut.close();} catch (Exception e) {e.printStackTrace();}}private static void createSheet(Workbook wb, String name, String version,List<JSONObject> rows, JSONObject rowKeys) {Integer max = getMaxRowNumber(version);int sheetNum = 1;Sheet sheet = wb.createSheet(name + sheetNum);CellStyle style = wb.createCellStyle();style.setAlignment(HorizontalAlignment.LEFT);//设置水平对齐方式style.setVerticalAlignment(VerticalAlignment.CENTER); //设置垂直对齐方式String firstRowKey = rowKeys != null ? rowKeys.getString("firstRow"):"firstRow";String lastRowKey  = rowKeys != null ? rowKeys.getString("lastRow"):"lastRow";String firstColKey = rowKeys != null ? rowKeys.getString("firstCol"):"firstCol";String lastColKey  = rowKeys != null ? rowKeys.getString("lastCol"):"lastCol";String valueKey    = rowKeys != null ? rowKeys.getString("value"):"value";for (JSONObject rowJson : rows) {int lastRow  = rowJson.getInteger(lastRowKey);if (lastRow > max){List<JSONObject> subRows = rows.subList(lastRow,rows.size());createSheet(wb, name, version, subRows,  rowKeys);} else{int firstRow = rowJson.getInteger(firstRowKey);int firstCol = rowJson.getInteger(firstColKey);int lastCol  = rowJson.getInteger(lastColKey);System.out.println(firstRow+"_"+lastRow +"_"+ firstCol +"_"+ lastCol);if (lastCol - firstCol > 0 || lastRow - firstRow > 0 ){CellRangeAddress cellRangeAddress = new CellRangeAddress(firstRow, lastRow, firstCol, lastCol);sheet.addMergedRegion(cellRangeAddress);}Row row ;if (sheet.getRow(firstRow)!=null){row = sheet.getRow(firstRow);} else {row = sheet.createRow(firstRow);}Cell cell = row.createCell(firstCol);cell.setCellValue(rowJson.getString(valueKey));cell.setCellStyle(style);}}}public static Workbook produce(String version) {switch (version) {case "xls":return new HSSFWorkbook();case "xlsx":return new XSSFWorkbook();case "sxlsx":return new SXSSFWorkbook();default:return null;}}private static int maxXls = 65024;private static int maxXlsx = 1048576;public static Integer getMaxRowNumber(String version) {switch (version) {case "xls":return maxXls;case "xlsx":return maxXlsx;case "sxlsx":return maxXlsx;default:return null;}}public static void main(String[] args) {try {List<JSONObject> list = (List<JSONObject>) JSONObject.parse("[{\"firstRow\":0,\"lastRow\":6,\"lastCol\":0,\"firstCol\":0,\"value\":\"秦时明月汉时关\"},{\"firstRow\":0,\"lastRow\":0,\"lastCol\":1,\"firstCol\":1,\"value\":\"万\"},{\"firstRow\":1,\"lastRow\":1,\"lastCol\":1,\"firstCol\":1,\"value\":\"里\"},{\"firstRow\":2,\"lastRow\":2,\"lastCol\":1,\"firstCol\":1,\"value\":\"长\"},{\"firstRow\":3,\"lastRow\":3,\"lastCol\":1,\"firstCol\":1,\"value\":\"征\"},{\"firstRow\":4,\"lastRow\":4,\"lastCol\":1,\"firstCol\":1,\"value\":\"人\"},{\"firstRow\":5,\"lastRow\":5,\"lastCol\":1,\"firstCol\":1,\"value\":\"未\"},{\"firstRow\":6,\"lastRow\":6,\"lastCol\":1,\"firstCol\":1,\"value\":\"还\"},{\"firstRow\":3,\"lastRow\":3,\"lastCol\":2,\"firstCol\":2,\"value\":\"但使龙城飞将在\"},{\"firstRow\":0,\"lastRow\":0,\"lastCol\":3,\"firstCol\":3,\"value\":\"不\"},{\"firstRow\":1,\"lastRow\":1,\"lastCol\":3,\"firstCol\":3,\"value\":\"教\"},{\"firstRow\":2,\"lastRow\":2,\"lastCol\":3,\"firstCol\":3,\"value\":\"胡\"},{\"firstRow\":3,\"lastRow\":3,\"lastCol\":3,\"firstCol\":3,\"value\":\"马\"},{\"firstRow\":4,\"lastRow\":4,\"lastCol\":3,\"firstCol\":3,\"value\":\"度\"},{\"firstRow\":5,\"lastRow\":5,\"lastCol\":3,\"firstCol\":3,\"value\":\"阴\"},{\"firstRow\":6,\"lastRow\":6,\"lastCol\":3,\"firstCol\":3,\"value\":\"山\"}]");writeMergeExcel("E:\\","mergeExcel", "xls" ,list);} catch (IOException e) {e.printStackTrace();}}
}

2.2 输出的Excel结果：

秦时明月汉时关	万		不
	里		教
	长		胡
	征	但使龙城飞将在	马
	人		度
	未		阴
	还		山

附录：

合并单元格的读取见另一篇文章：

Java读取Excel中的合并单元格https://blog.csdn.net/u012998680/article/details/124557925

Java：Excel写入“合并单元格“相关推荐

JAVA EXCEL导出合并单元格自定义封装方法
转载在C站上面看到一个大神写的自定义封装方法转载地址:springboot 使用Poi 自定义封装方法合并excel中的单元格_Tongyao-CSDN博客_springboot合并单元格之前都 ...
Java 利用hutool工具实现导出excel并合并单元格
Java 利用hutool工具实现导出excel并合并单元格 controller层调用service,就一个核心方法,没错就下面这个代码就能实现了.前提是项目里面要引用hutool包.把我这个复制到 ...
Springboot导出excel，合并单元格示例
原文链接:Springboot导出excel,合并单元格示例更多文章,欢迎访问:Java知音,一个专注于技术分享的网站以下用一个示例来说明springboot如何导出数据到excel. 首先引入M ...
玩电脑的岂能不知道excel怎么合并单元格？
excel怎么合并单元格?单元格太小导致输入的内容只能看见一部分,这种情况下需要将两列合并起来,空出更多输入内容的空间,以此达到美观又详细的视觉效果,下面来看看如何操作吧! 方法一第1步:打开一个e ...
POI进行Excel的合并单元格数据处理
POI进行Excel的合并单元格数据处理近日接到一个要处理合并Excel单元格的上料表的需求,就到网上找了一些模板,发现有的技术大牛还是挺厉害的,对他们致以敬意. 合并单元格工具类在这个类中将传入 ...
html表格里面怎么合并单元格的快捷键,合并单元格快捷键：Excel怎么合并单元格...
今天来聊聊一篇关于合并单元格快捷键:Excel怎么合并单元格的文章,现在就为大家来简单介绍下合并单元格快捷键:Excel怎么合并单元格,希望对各位小伙伴们有所帮助. 方法如下: 1.首先我们需要将&q ...
【excel】合并单元格拆分后每一格都填充为与原来相同内容
用的比较频繁的一个操作,单元格合并拆分出的单元格自动填充为合并前内容比较烦合并单元格,记得以前看过一本excel书里把合并单元格列为一大恶习,因为这严重影响数据分析,但那本书没说怎么处理,导致我才学 ...
【VB6.0 数据库连接EXCEL查询合并单元格成功解决办法】
[VB6.0 数据库连接EXCEL查询合并单元格成功解决办法] Private Sub Command1_Click() On Error Resume Next Dim i As Integer, ...
Excel 中合并单元格的快捷键（ALT+H+M+M）
要在 excel 中合并单元格,首先选择要合并到一个单元格中的单元格,然后可以使用从ALT开始的快捷键,然后同时按H+M+M. 一旦我们使用快捷键执行该函数,它将弹出一条警告消息"合并单元格 ...

Java：Excel写入“合并单元格“