poi+easypoi实现表头多层循环，多级动态表头、树形结构动态表头、纵向合并单元格、多个sheet导出

前言

我前面也写过几篇关于easypoi复杂表格导出的文章，什么一对多纵向合并、多级表头、动态表头、多个sheet等，这些我写那几篇文章之前做项目都遇到过，并且都实现出来了。

感兴趣的可以看看：
easypoi多级表头、多个sheet导出，动态导出列、动态更改表头

easypoi一对多，纵向合并单元格，并且根据内容自适应行高

我就以为大部分表格导出都难不倒我了，没想到我碰到的表格还是不够多。

多级表头中，不知道大家有没有碰到过这种表头，如下图：

三级下面有n个四级，一级二级下面分别只有一个二级和三级。亦或是这种：

我一开始寻思这种表头用easypoi的 excelExportEntity 实现挺简单的呀，后面我用代码写了才发现这结果完全不是我想的样子啊😂上面那两张图是想要的理想效果，实际上的结果是这样的：

和这样的：

我直接：

这种情况就是合并单元格只能作用于上一级，而不能跨级。比如对二级来说，四级是它子级的子级，但是它并不能因为子级（三级）有多个子级，所以子级（三级）合并了，它本身也会合并。 用easypoi来导出的话，关于这个问题，我现在没有找到解决方案。

还有一点就是我明明每列都设置了列宽，但是四级3、四级4的列宽没起作用，四级1、四级2设置的列宽倒是起作用了。

发现用 ExcelExportEntity 行不通后，有想过使用模板，但是我项目中实际用的表头比较复杂，我用模板完全不知道要怎么把表头遍历出来。。。项目里用的大概是这种形式的表头：

我不知道在模板里遍历每一项的时候，怎么再遍历每一项里面的list。就是遍历一级时，怎么再把每个一级下面的二级list给遍历出来。我看了easypoi的官方文档，发现有个 模板支持多层循环 的实现，但是偏偏就这一点，它文档上的图片没了。。。

然后我开始找其他解决办法，看过很多关于easypoi复杂表头的文章，都没有找到我这种形式的表格。直到我看某篇文章的评论区时，终于看到个有遇到和我一样问题的人了，并且贴出了参考方案，我按照这个方法，终于做出来我想要的表头了！！解决方案我就是参考的这篇文章：JAVA POI 实现EXCEL 动态表头、动态添加数据（导入导出）、 Tree结构的遍历

解决

一、表头效果

我按照上面那篇文章，终于得到我想要的表头了，效果如图：


设置的列宽也有作用。

再看看用easypoi ExcelExportEntity 导出来的：

我设置的列宽也不起作用。

二、填充数据

表头可以了，接下来就是填充内容数据了，效果如下：

这里就有个问题了，因为所在单位这一列有连续多行是相同内容，所以我想要合并相同内容。

1、纵向合并

于是我在原先的代码基础上，加了纵向合并功能，需要设置哪几列是遇到相同内容要合并的。

private void writeSheetContent(List<ColEntity> headerCellList, List<T> datas, HSSFSheet sheet, int rowIndex,List<Integer> mergeIndex, boolean rowFlag) throws Exception {    boolean isMerge = false;// 是否纵向合并单元格    if (mergeIndex != null && !mergeIndex.isEmpty()) isMerge = true;    HSSFRow row = null;    List<ColEntity> listCol = new ArrayList<>();    rowFlag = false;    if (rowFlag) {//暂时没有用 后面扩展用        for (int i = 0, index = rowIndex; i < datas.size(); i++, index++) {            row = sheet.createRow(index);//创建行            for (int j = 0; j < headerCellList.size(); j++) {                createColl(row, j, headerCellList.get(j).getFieldName(), datas.get(i));            }        }    } else {        getColEntityList(headerCellList, listCol);        Map<Integer,  Map<Integer, String>> mergeMaps = new HashMap<>();// 需要合并的列：key 列号，value为单元格内容        Map<Integer, String> mergeMap = null;// 需要合并的行：key 行号 value 为单元格内容        for (int i = 0, index = rowIndex; i < datas.size(); i++, index++) {            row = sheet.createRow(index);//创建行            for (int j = 0; j < listCol.size(); j++) {                ColEntity c = listCol.get(j);                //数据列                HSSFCell col = createCol(row, c, datas.get(i));                if (col.toString().length()>0){                    // 需要合并 并且 当前单元格所在的列包含在要合并的列中                    if (isMerge && mergeIndex.contains(c.getCol())){                        if (mergeMaps.get(c.getCol()) != null){ // 如果要合并的列已经有了，则直接去拿该列的数据mergeMap = mergeMaps.get(c.getCol());                        }else {mergeMap = new HashMap<>();                        }                        // 当前行号为key，当前单元格内容为value                        mergeMap.put(index,col.toString()); // 将当前单元格的内容添加到当前行号中                        mergeMaps.put(c.getCol(),mergeMap);                    }                }            }        }        if (isMerge) mergedCells(mergeMaps,sheet);    }}private void mergedCells(Map<Integer,  Map<Integer, String>> mergeMaps,HSSFSheet sheet){    for (Integer colNum : mergeMaps.keySet()) { // 遍历要合并的列，获取每一列的每一行        Map<Integer, String> mergeMap = mergeMaps.get(colNum);// 当前这列每一行的内容：key为行号，value为单元格内容        // 根据mergeMap的value，也就是单元格内容进行分组，每一组都是需要合并在一起的单元格（要合并的区域）        Map<String, List<Map.Entry<Integer,String>>>result = mergeMap.entrySet().stream().collect(Collectors.groupingBy(c -> c.getValue()));        System.out.println("\n合并的列号："+colNum);        System.out.println("合并的区域："+result);        for (String key : result.keySet()) {            // list为这一组要合并的几个单元格            List<Map.Entry<Integer, String>> list = result.get(key);            int start = list.get(0).geTKEy(); // 开始合并的行号            int end = list.get(list.size()-1).getKey(); // 结束合并的行号            System.out.println("第"+colNum+"列开始合并的行号："+start+"\t第"+colNum+"列结束合并的行号："+"\t"+end+"。");            if (start < end){ // 开始合并的行号必须小于结束合并的行号                sheet.addMergedRegion(new CellRangeAddress(start, end, colNum,colNum));            }        }    }}

写好纵向合并的方法后，我们再来看看导出效果：（行号索引从0开始）

2、多个sheet

实现了纵向合并，项目中又根本不止一个sheet，所以我们还得实现导出多个sheet。

我在原先代码调用导出方法的基础上，再对这个方法传入的参数进行重新封装。原先是表头数据和内容数据都用的list，要实现多个sheet的话，我再用map把每个sheet的表头数据list、内容数据list给封装起来，用sheet名称为key。

public HSSFWorkbook exportWorkbook(List<ColEntity> listTpamsColEntity, List<T> datas) throws Exception {    splitDataToSheets(this.title,datas, listTpamsColEntity,null, false);    ExcelStyleUtil.setStyleByType(this.workbook,null,0,null);    return this.workbook;}public HSSFWorkbook exportWorkbook(Map<String,List<ColEntity>> titles, Map<String,List<T>> datas) throws Exception {    for (String sheetName : titles.keySet()) {        List<ColEntity> colEntityList = titles.get(sheetName);        List<T> tList = datas.get(sheetName);        splitDataToSheets(sheetName,tList, colEntityList,null,false);    }    ExcelStyleUtil.setStyleByType(this.workbook,null,0,null);    return this.workbook;}

最后导出如图：

三、完整代码

<dependencies>        <dependency>        <groupId>javax.servletgroupId>        <artifactId>servlet-apiartifactId>        <version>2.5version>    dependency>        <dependency>        <groupId>cn.afterturngroupId>        <artifactId>easypoi-baseartifactId>        <version>4.4.0version>    dependency>dependencies>

1、表头实体类

用于封装表头内容。可以将数据库查出来的动态表头数据用这个实体类封装起来，也可以直接用数据库表映射的实体类

public class TitleEntity {        public  String id;        public  String pid;        public  String content;        public  String fieldName;        public int width;    private TitleEntity(){}    public TitleEntity(String id, String pid, String content, String fieldName, int width) {        this.id = id;        this.pid = pid;        this.content = content;        this.fieldName = fieldName;        this.width = width;    }    // ......省略getter、setter}

2、单元格实体类

import java.util.ArrayList;import java.util.List;public class ColEntity {        private String content;        private String fieldName;        private List<ColEntity> cellList = new ArrayList<ColEntity>();        private int totalRow;        private int totalCol;        private int row;        private int col;        private int rLen;        private int cLen;        private boolean hasChildren;        private int treeStep;        private String id;        private String pid;        private int width;        // ......省略getter、setter}

3、构建树形结构工具类

import com.entity.ColEntity;import java.util.ArrayList;import java.util.Collections;import java.util.Iterator;import java.util.List;public class ExcelTreeUtil {            public static int getTreeStep(List<ColEntity> list, String id, int step) {        if ("".equals(id) || null == id) return step;        for (ColEntity cc : list) {            if (id.equals(cc.getId())) {                int temp = step + 1;                return getTreeStep(list, cc.getPid(), temp);            }        }        return step;    }        public static int getMaxStep(List<ColEntity> list) {        List<Integer> nums = new ArrayList<>();        for (ColEntity cc : list) {            nums.add(getTreeStep(list, cc.getId(), 0));        }        return Collections.max(nums);    }        public static int getDownChildren(List<ColEntity> list, String did) {        int sum = 0;        for (ColEntity cc : list) {            if (did.equals(cc.getPid())) {                sum++;                //判断该节点 是否有子节点                if (hasChild(list, cc)) {                    sum += getDownChildren(list, cc.getId()) - 1;                }            }        }        return sum;    }        public static ColEntity getParentCol(List<ColEntity> list, String did) {        for (ColEntity cc : list) {            if (did != null && did.equals(cc.getId())) {                return cc;            }            if (did == null && did == cc.getId()) {                return cc;            }        }        return new ColEntity() {{            setCol(0);            setRow(0);        }};    }        public static int getBrotherChilNum(List<ColEntity> list, ColEntity ColEntity) {        int sum = 0;        for (ColEntity cc : list) {            if (ColEntity.getId().equals(cc.getId())) {                break;            }            if (!ColEntity.getPid().equals(cc.getPid())) {                continue;            }            int temp = getDownChildren(list, cc.getId());            if (temp == 0 || temp == 1) {                sum++;            } else {                sum += temp;            }        }        return sum;    }        public static String getStepParentId(List<ColEntity> list, String id, int step) {        String f_id = null;        for (ColEntity cc : list) {            if (id.equals(cc.getId())) {                int cstep = getTreeStep(list, cc.getId(), 0);                if (step == cstep) {                    return id;                }                int fstep = getTreeStep(list, cc.getPid(), 0);                if (step == fstep) {                    f_id = cc.getPid();                    break;                } else {                    getStepParentId(list, cc.getPid(), step);                }            }        }        return f_id;    }        public static boolean hasChild(List<ColEntity> list, ColEntity node) {        return getChildList(list, node).size() > 0;    }        public static List<ColEntity> getChildList(List<ColEntity> list, ColEntity node) {        List<ColEntity> nodeList = new ArrayList<>();        Iterator<ColEntity> it = list.iterator();        while (it.hasNext()) {            ColEntity n = (ColEntity) it.next();            if (n.getPid() != null && n.getPid().equals(node.getId())) {                nodeList.add(n);            }        }        return nodeList;    }        public static List<ColEntity> buildByRecursive(List<ColEntity> treeNodes, String rootID) {        List<ColEntity> trees = new ArrayList<>();        boolean flag = false;        boolean sflag = false;        for (ColEntity treeNode : treeNodes) {            if ((rootID == null && rootID == treeNode.getId())) {                flag = true;            }            if (rootID != null && rootID.equals(treeNode.getId())) {                flag = true;            }            if (flag) {                trees.add(findChildren(treeNode, treeNodes));                flag = false;            }        }        if (trees.size() <= 0) {            for (ColEntity treeNode : treeNodes) {                if ((rootID == null && rootID == treeNode.getPid())) {                    sflag = true;                }                if (rootID != null && rootID.equals(treeNode.getPid())) {                    sflag = true;                }                if (sflag) {                    trees.add(findChildren(treeNode, treeNodes));                    sflag = false;                }            }        }        return trees;    }        public static ColEntity findChildren(ColEntity treeNode, List<ColEntity> treeNodes) {        for (ColEntity it : treeNodes) {            if (treeNode.getId().equals(it.getPid())) {                if (treeNode.getCellList() == null) {                    treeNode.setCellList(new ArrayList<>());                }                treeNode.getCellList().add(findChildren(it, treeNodes));            }        }        return treeNode;    }}

4、excel导出样式工具类

import cn.afterturn.easypoi.excel.entity.params.ExcelExportEntity;import cn.afterturn.easypoi.excel.entity.params.ExcelForEachParams;import cn.afterturn.easypoi.excel.export.styler.IExcelExportStyler;import org.apache.poi.ss.usermodel.*;import java.util.List;public class ExcelStyleUtil implements IExcelExportStyler {    private ExcelStyleUtil(){}    private static final short STRING_FORMAT = (short) BuiltinFormats.getBuiltinFormat("TEXT");    private static final short FONT_SIZE_TEN = 10;    private static final short FONT_SIZE_ELEVEN = 11;    private static final short FONT_SIZE_TWELVE = 12;    private static final short height = 30;        private CellStyle headerStyle;        private CellStyle titleStyle;        private CellStyle styles;    public ExcelStyleUtil(Workbook workbook) {        this.init(workbook);    }        private void init(Workbook workbook) {        this.headerStyle = initHeaderStyle(workbook);        this.titleStyle = initTitleStyle(workbook,true,FONT_SIZE_ELEVEN);        this.styles = initStyles(workbook);    }    @Override    public CellStyle getHeaderStyle(short i) {        return headerStyle;    }    @Override    public CellStyle getTitleStyle(short i) {        return titleStyle;    }    @Override    public CellStyle getTemplateStyles(boolean b, ExcelForEachParams excelForEachParams) {        return null;    }    @Override    public CellStyle getStyles(boolean b, ExcelExportEntity excelExportEntity) {        return styles;    }    @Override    public CellStyle getStyles(Cell cell, int i, ExcelExportEntity entity, Object o, Object o1) {        return getStyles(true, entity);    }        public static CellStyle getStyles(Workbook workbook,int style) {        CellStyle cellStyle = null;        switch (style){            case 1:                cellStyle = initHeaderStyle(workbook);                break;            case 2:                cellStyle = initTitleStyle(workbook,true,FONT_SIZE_ELEVEN);                break;            case 3:                cellStyle = initStyles(workbook);                break;            default:                cellStyle = initStyles(workbook);                break;        }        cellStyle.setDataFormat(STRING_FORMAT);        return cellStyle;    }        private static CellStyle initHeaderStyle(Workbook workbook) {        CellStyle style = getBaseCellStyle(workbook);        style.setFont(getFont(workbook, FONT_SIZE_TWELVE, true));        return style;    }        private static CellStyle initTitleStyle(Workbook workbook,boolean isBold,short size) {        CellStyle style = getBaseCellStyle(workbook);        style.setFont(getFont(workbook, size, isBold));        //背景色        style.setFillForegroundColor(IndexedColors.TAN.getIndex());        style.setFillPattern(FillPatternType.SOLID_FOREGROUND);        return style;    }        private static CellStyle initStyles(Workbook workbook) {        CellStyle style = getBaseCellStyle(workbook);        style.setFont(getFont(workbook, FONT_SIZE_TEN, false));        style.setDataFormat(STRING_FORMAT);        return style;    }        public static CellStyle getRowBackground(Workbook workbook) {        CellStyle style = getBaseCellStyle(workbook);        style.setFont(getFont(workbook, FONT_SIZE_TEN,false));        //背景色        style.setFillForegroundColor(IndexedColors.LAVENDER.getIndex());        style.setFillPattern(FillPatternType.SOLID_FOREGROUND);        style.setDataFormat(STRING_FORMAT);        return style;    }        private static CellStyle getBaseCellStyle(Workbook workbook) {        CellStyle style = workbook.createCellStyle();        //下边框        style.setBorderBottom(BorderStyle.THIN);        //左边框        style.setBorderLeft(BorderStyle.THIN);        //上边框        style.setBorderTop(BorderStyle.THIN);        //右边框        style.setBorderRight(BorderStyle.THIN);        //水平居中        style.setAlignment(HorizontalAlignment.CENTER);        //上下居中        style.setVerticalAlignment(VerticalAlignment.CENTER);        //设置自动换行        style.setWrapText(true);        return style;    }        private static Font getFont(Workbook workbook, short size, boolean isBold) {        Font font = workbook.createFont();        //字体样式        font.setFontName("宋体");        //是否加粗        font.setBold(isBold);        //字体大小        font.setFontHeightInPoints(size);        return font;    }        public static void setStyleByType(Workbook workbook,String sheetName,int type,List<Integer> autoRowHeight){        if (sheetName != null && sheetName.length()>0){            Sheet sheet = workbook.getSheet(sheetName);            setSheetStyleByType(workbook,sheet,type,autoRowHeight);        }else {            int sheetNum = workbook.getNumberOfSheets();            for (int i = 0; i < sheetNum; i++) {                Sheet sheet = workbook.getSheetAt(i);                setSheetStyleByType(workbook,sheet,type,autoRowHeight);            }        }    }    public static void setSheetStyleByType(Workbook workbook,Sheet sheet,int type,List<Integer> autoRowHeight){        if (type==1 || type == 3){ // 1和3，设置隔行背景            setRowBackground(workbook,sheet);        }        int lastRowNum = sheet.getLastRowNum();        for(int j = 0; j <= lastRowNum; j++) {            Row row = sheet.getRow(j);            row.setHeightInPoints(height); // 默认行高            if (type==2 || type == 3){ // 2和3，设置自适应行高                if (autoRowHeight != null && autoRowHeight.contains(j)){ // 不为空，则只有指定行号的行需要自适应行高                    autoRowHeight(row);                }else { // 为null，则表示全部行都需要自适应行高                    autoRowHeight(row);                }            }        }    }        public static void setRowBackground(Workbook workbook,Sheet sheet){        CellStyle styles = getRowBackground(workbook);        for(int i = 0; i <= sheet.getLastRowNum(); i ++) {            if (i%2==0 && i>0){ // 标题用全局的标题样式，就不单独设置样式了，所以排除标题                Row row = sheet.getRow(i);                for(int j = 0; j < row.getPhysicalNumberOfCells(); j ++) {                    Cell cell = row.getCell(j);                    cell.setCellStyle(styles);                }            }        }    }        public static void autoRowHeight(Row row){        //根据内容长度设置行高        int enterCnt = 0;        for(int j = 0; j < row.getPhysicalNumberOfCells(); j ++) {            Cell cell = row.getCell(j);            if (cell != null){                int rwsTemp = row.getCell(j).toString().length();                //这里取每一行中的每一列字符长度最大的那一列的字符                if (rwsTemp > enterCnt) {                    enterCnt = rwsTemp;                }            }        }        row.setHeightInPoints(height); // 设置默认行高为35        //如果字符长度大于35，根据内容来设置相应的行高        if (enterCnt>height){            long d = Math.round((double) enterCnt / (double) height)+2;            row.setHeightInPoints(enterCnt*d);        }    }}

5、excel poi导出处理工具类

import com.entity.ColEntity;import org.apache.poi.hssf.usermodel.*;import org.apache.poi.ss.usermodel.*;import org.apache.poi.ss.util.CellRangeAddress;import org.apache.poi.ss.util.RegionUtil;import java.io.File;import java.io.FileOutputStream;import java.lang.reflect.Field;import java.text.SimpleDateFormat;import java.util.*;import java.util.stream.Collectors;public class ExcelPoiUtil<T> {        private HSSFWorkbook workbook;        private String title;        private CellStyle styleHead;        private CellStyle styleBody;        private SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");    public HSSFWorkbook getWorkbook() {        return workbook;    }    public void setWorkbook(HSSFWorkbook workbook) {        this.workbook = workbook;    }    public String getTitle() {        return title;    }    public void setTitle(String title) {        this.title = title;    }    public CellStyle getStyleHead() {        return styleHead;    }    public void setStyleHead(CellStyle styleHead) {        this.styleHead = styleHead;    }    public CellStyle getStyleBody() {        return styleBody;    }    public void setStyleBody(CellStyle styleBody) {        this.styleBody = styleBody;    }    public SimpleDateFormat getSdf() {        return sdf;    }    public void setSdf(SimpleDateFormat sdf) {        this.sdf = sdf;    }        public ExcelPoiUtil() {        this.title = "sheet1";        this.workbook = new HSSFWorkbook();        init();    }    public ExcelPoiUtil(String title) {        this.title = title;        this.workbook = new HSSFWorkbook();        init();    }        private void init() {        this.styleHead = ExcelStyleUtil.getStyles(workbook,2);        this.styleBody = ExcelStyleUtil.getStyles(workbook,3);    }        public HSSFWorkbook exportWorkbook(List<ColEntity> listTpamsColEntity, List<T> datas) throws Exception {        splitDataToSheets(this.title,datas, listTpamsColEntity,null, false);        ExcelStyleUtil.setStyleByType(this.workbook,null,0,null);        return this.workbook;    }        public HSSFWorkbook exportWorkbook(List<ColEntity> listTpamsColEntity, List<T> datas,List<Integer> mergeIndex) throws Exception {        splitDataToSheets(this.title,datas, listTpamsColEntity, mergeIndex,false);        ExcelStyleUtil.setStyleByType(this.workbook,null,0,null);        return this.workbook;    }        public HSSFWorkbook exportWorkbook(List<ColEntity> listTpamsColEntity, List<T> datas,int type,List<Integer> autoRowHeight) throws Exception {        splitDataToSheets(this.title,datas, listTpamsColEntity,null, false);        ExcelStyleUtil.setStyleByType(this.workbook,null,type,autoRowHeight);        return this.workbook;    }        public HSSFWorkbook exportWorkbook(List<ColEntity> listTpamsColEntity, List<T> datas,int type,List<Integer> autoRowHeight,List<Integer> mergeIndex) throws Exception {        splitDataToSheets(this.title,datas, listTpamsColEntity,mergeIndex, false);        ExcelStyleUtil.setStyleByType(this.workbook,null,type,autoRowHeight);        return this.workbook;    }        public HSSFWorkbook exportWorkbook(Map<String,List<ColEntity>> titles, Map<String,List<T>> datas,int type,List<Integer> autoRowHeight,List<Integer> mergeIndex) throws Exception {        for (String sheetName : titles.keySet()) {            List<ColEntity> colEntityList = titles.get(sheetName);            List<T> tList = datas.get(sheetName);            splitDataToSheets(sheetName,tList, colEntityList,mergeIndex,false);        }        ExcelStyleUtil.setStyleByType(this.workbook,null,type,autoRowHeight);        return this.workbook;    }        public HSSFWorkbook exportWorkbook(Map<String,List<ColEntity>> titles, Map<String,List<T>> datas,Map<String,Integer> types,           Map<String,List<Integer>> autoRowHeights,Map<String,List<Integer>> mergeIndexs) throws Exception {        for (String sheetName : titles.keySet()) {            List<ColEntity> colEntityList = titles.get(sheetName);            List<T> tList = datas.get(sheetName);            int type = types == null ? 0 : types.get(sheetName) == null ? 0 : types.get(sheetName);            List<Integer> autoRowHeight = autoRowHeights == null ? null : autoRowHeights.get(sheetName);            List<Integer> mergeIndex = mergeIndexs == null ? null : mergeIndexs.get(sheetName);            splitDataToSheets(sheetName,tList, colEntityList,mergeIndex,false);            ExcelStyleUtil.setStyleByType(this.workbook,sheetName,type,autoRowHeight);        }        return this.workbook;    }        public void save(HSSFWorkbook workbook, String filePath) {        File file = new File(filePath);        if (!file.getParentFile().exists()) {            file.getParentFile().mkdirs();        }        FileOutputStream fOut = null;        try {            fOut = new FileOutputStream(file);            workbook.write(fOut);            fOut.flush();        } catch (Exception e) {            e.printStackTrace();        }        try {            if (null != fOut) {                fOut.close();            }        } catch (Exception e1) {        }    }        private void writeSheet(HSSFSheet sheet, List<T> data, List<ColEntity> headerCellList,List<Integer> mergeIndex,boolean rowFlag) throws Exception {        sheet = createHead(sheet, headerCellList.get(0).getTotalRow(), headerCellList.get(0).getTotalCol());        createHead(headerCellList, sheet, 0);        writeSheetContent(headerCellList, data, sheet, headerCellList.get(0).getTotalRow(),mergeIndex, rowFlag);    }        private void splitDataToSheets(String sheetName,List<T> data, List<ColEntity> headerCellList,List<Integer> mergeIndex,boolean rowFlag) throws Exception {        int dataCount = data.size();        int maxColEntity = 65535;        int pieces = dataCount / maxColEntity;        for (int i = 1; i <= pieces; i++) {            HSSFSheet sheet = this.workbook.createSheet(sheetName + i);            List<T> subList = data.subList((i - 1) * maxColEntity, i * maxColEntity);            writeSheet(sheet, subList, headerCellList,mergeIndex,rowFlag);        }        HSSFSheet sheet = this.workbook.createSheet(sheetName);        writeSheet(sheet, data.subList(pieces * maxColEntity, dataCount), headerCellList,mergeIndex,rowFlag);    }        private void writeSheetContent(List<ColEntity> headerCellList, List<T> datas, HSSFSheet sheet, int rowIndex,List<Integer> mergeIndex, boolean rowFlag) throws Exception {        boolean isMerge = false;// 是否纵向合并单元格        if (mergeIndex != null && !mergeIndex.isEmpty()) isMerge = true;        HSSFRow row = null;        List<ColEntity> listCol = new ArrayList<>();        rowFlag = false;        if (rowFlag) {//暂时没有用 后面扩展用            for (int i = 0, index = rowIndex; i < datas.size(); i++, index++) {                row = sheet.createRow(index);//创建行                for (int j = 0; j < headerCellList.size(); j++) {                    createColl(row, j, headerCellList.get(j).getFieldName(), datas.get(i));                }            }        } else {            getColEntityList(headerCellList, listCol);            Map<Integer,  Map<Integer, String>> mergeMaps = new HashMap<>();// 需要合并的列：key 列号，value为单元格内容            Map<Integer, String> mergeMap = null;// 需要合并的行：key 行号 value 为单元格内容            for (int i = 0, index = rowIndex; i < datas.size(); i++, index++) {                row = sheet.createRow(index);//创建行                for (int j = 0; j < listCol.size(); j++) {                    ColEntity c = listCol.get(j);                    //数据列                    HSSFCell col = createCol(row, c, datas.get(i));                    if (col.toString().length()>0){                        // 需要合并 并且 当前单元格所在的列包含在要合并的列中                        if (isMerge && mergeIndex.contains(c.getCol())){if (mergeMaps.get(c.getCol()) != null){ // 如果要合并的列已经有了，则直接去拿该列的数据    mergeMap = mergeMaps.get(c.getCol());}else {    mergeMap = new HashMap<>();}// 当前行号为key，当前单元格内容为valuemergeMap.put(index,col.toString()); // 将当前单元格的内容添加到当前行号中mergeMaps.put(c.getCol(),mergeMap);                        }                    }                }            }            if (isMerge) mergedCells(mergeMaps,sheet);        }    }        private void mergedCells(Map<Integer,  Map<Integer, String>> mergeMaps,HSSFSheet sheet){        for (Integer colNum : mergeMaps.keySet()) { // 遍历要合并的列，获取每一列的每一行            Map<Integer, String> mergeMap = mergeMaps.get(colNum);// 当前这列每一行的内容：key为行号，value为单元格内容            // 根据mergeMap的value，也就是单元格内容进行分组，每一组都是需要合并在一起的单元格（要合并的区域）            Map<String, List<Map.Entry<Integer,String>>>result = mergeMap.entrySet().stream().collect(Collectors.groupingBy(c -> c.getValue()));            System.out.println("\n合并的列号："+colNum);            System.out.println("合并的区域："+result);            for (String key : result.keySet()) {                // list为这一组要合并的几个单元格                List<Map.Entry<Integer, String>> list = result.get(key);                int start = list.get(0).getKey(); // 开始合并的行号                int end = list.get(list.size()-1).getKey(); // 结束合并的行号                System.out.println("第"+colNum+"列开始合并的行号："+start+"\t第"+colNum+"列结束合并的行号："+"\t"+end+"。");                if (start < end){ // 开始合并的行号必须小于结束合并的行号                    sheet.addMergedRegion(new CellRangeAddress(start, end, colNum,colNum));                }            }        }    }        private void createColl(HSSFRow row, int j, String finame, T t) {        HSSFCell cell = row.createCell(j);  //创建单元格        cell.setCellStyle(this.styleBody); //设置单元格样式        String text = "";        if (t instanceof List) {            List<Map> temp = (List<Map>) t;            if (j >= temp.size()) {                return;            }            text = String.valueOf(temp.get(j).get(finame) == null ? "" : temp.get(j).get(finame));        }        HSSFRichTextString richString = new HSSFRichTextString(text);        cell.setCellValue(richString);    }        private void getColEntityList(List<ColEntity> list, List<ColEntity> listCol) {        for (ColEntity ColEntity : list) {            if (ColEntity.getFieldName() != null) {                listCol.add(ColEntity);            }            List<ColEntity> listChildren = ColEntity.getCellList();            if (listChildren.size() > 0) {                getColEntityList(listChildren, listCol);            }        }    }        public int createRowVal(HSSFRow row, ColEntity tpamsColEntity, T v, int j) throws Exception {        //遍历标题        if (tpamsColEntity.getCellList() != null && tpamsColEntity.getCellList().size() > 0) {            for (int i = 0; i < tpamsColEntity.getCellList().size(); i++) {                createRowVal(row, tpamsColEntity.getCellList().get(i), v, j);            }        } else {            createCol(row, tpamsColEntity, v);        }        return j;    }        public HSSFCell createCol(HSSFRow row, ColEntity colEntity, T v) throws Exception {        HSSFCell cell = row.createCell(colEntity.getCol());  //创建单元格        cell.setCellStyle(this.styleBody); //设置单元格样式        final Object[] value = {null};        if (v instanceof Map) {            Map m = (Map) v;            m.forEach((k, val) -> {                if (k.equals(colEntity.getFieldName()) && !colEntity.isHasChildren()) {                    value[0] = val;                }            });        } else {            Class<?> cls = v.getClass();// 拿到该类            Field[] fields = cls.getDeclaredFields();// 获取实体类的所有属性，返回Field数组            for (int i = 0; i < fields.length; i++) {                Field f = fields[i];                f.setAccessible(true); // 设置些属性是可以访问的                if (colEntity.getFieldName().equals(f.getName()) && !colEntity.isHasChildren()){                    value[0] = f.get(v);                }                if (value[0] instanceof Date) {                    value[0] = parseDate((Date) value[0]);                }            }        }        if (value[0] != null) {            HSSFRichTextString richString = new HSSFRichTextString(value[0].toString());            cell.setCellValue(richString);        }        return cell;    }        private String parseDate(Date date) {        String dateStr = "";        try {            dateStr = this.sdf.format(date);        } catch (Exception e) {            e.printStackTrace();        }        return dateStr;    }        public HSSFSheet createHead(HSSFSheet sheetCo, int r, int c) {        for (int i = 0; i < r; i++) {            HSSFRow row = sheetCo.createRow(i);            for (int j = 0; j < c; j++) {                HSSFCell cell = row.createCell(j);            }        }        return sheetCo;    }        public void createHead(List<ColEntity> cellList, HSSFSheet sheetCo, int rowIndex) {        HSSFRow row = sheetCo.getRow(rowIndex);        int len = cellList.size();//当前行 有多少列        for (int i = 0; i < len; i++) {//i是headers的索引，n是Excel的索引 多级表头            ColEntity colEntity = cellList.get(i);            //创建这一行的第几列单元格            int r = colEntity.getRow();            int rLen = colEntity.getRLen();            int c = colEntity.getCol();            int cLen = colEntity.getCLen();            int endR = r + rLen;            //解决表头导出时多一行问题            if(endR > r){                endR--;            }            int endC = c + cLen;            if (endC > c) {                endC--;            }            HSSFCell cell = row.getCell(c);            HSSFRichTextString text = new HSSFRichTextString(colEntity.getContent());            cell.setCellStyle(this.styleHead); //设置表头样式            cell.setCellValue(text);            // 合并单元格            CellRangeAddress cra = new CellRangeAddress(r, endR, c, endC);            //todo debug            if (cra.getNumberOfCells() > 1) {                sheetCo.addMergedRegion(cra);            }            sheetCo.setColumnWidth(c,colEntity.getWidth()*256);// 设置列宽            // 使用RegionUtil类为合并后的单元格添加边框            RegionUtil.setBorderBottom(BorderStyle.THIN, cra, sheetCo); // 下边框            RegionUtil.setBorderLeft(BorderStyle.THIN, cra, sheetCo); // 左边框            RegionUtil.setBorderRight(BorderStyle.THIN, cra, sheetCo); // 有边框            if (colEntity.isHasChildren()) {                rowIndex = r + 1;                createHead(colEntity.getCellList(), sheetCo, rowIndex);            }        }    }        public List<ColEntity> colEntityTransformer(List<T> list) {        List<ColEntity> lc = new ArrayList<>();        if (list.get(0) instanceof Map) {            final int[] i = {1};            for (Map<String, String> m : (List<Map<String, String>>) list) {                m.forEach((k, val) -> {                    ColEntity tpamsColEntity = new ColEntity();                    tpamsColEntity.setId(String.valueOf(i[0]));                    tpamsColEntity.setPid("0");                    tpamsColEntity.setContent(k);                    tpamsColEntity.setFieldName(val);                    tpamsColEntity.setWidth(20);                    lc.add(tpamsColEntity);                    i[0]++;                });            }        } else {            int i = 1;            for (String s : (List<String>) list) {                ColEntity tpamsColEntity = new ColEntity();                tpamsColEntity.setId(String.valueOf(i));                tpamsColEntity.setPid("0");                tpamsColEntity.setContent(s);                tpamsColEntity.setFieldName(null);                tpamsColEntity.setWidth(20);                lc.add(tpamsColEntity);                i++;            }        }        setParm(lc, "0");//处理一下        List<ColEntity> s = ExcelTreeUtil.buildByRecursive(lc, "0");        setColNum(lc, s);        return s;    }        public List<ColEntity> colEntityTransformer(List<T> list, Map<String,String> parm,String rootid) throws Exception {        List<ColEntity> lc = new ArrayList<>();        if (list.get(0) instanceof Map) {            for (Map m : (List<Map>) list) {                ColEntity colEntity = new ColEntity();                m.forEach((k, val) -> {                    if (parm.get("id").equals(k)) {                        colEntity.setId(String.valueOf(val));                    }                    if (parm.get("pid").equals(k)) {                        colEntity.setPid((String) val);                    }                    if (parm.get("content").equals(k)) {                        colEntity.setContent((String) val);                    }                    if (parm.get("fieldName") != null && parm.get("fieldName").equals(k)) {                        colEntity.setFieldName((String) val);                    }                    if (parm.get("width") != null && parm.get("width").equals(k)) {                        colEntity.setWidth(Integer.parseInt(val.toString()));                    }                });                lc.add(colEntity);            }        } else {            for (T t : list) { // 反射                ColEntity colEntity = new ColEntity();                Class cls = t.getClass();                Field[] fs = cls.getDeclaredFields();                for (int i = 0; i < fs.length; i++) {                    Field f = fs[i];                    f.setAccessible(true); // 设置些属性是可以访问的                    if (parm.get("id").equals(f.getName()) && f.get(t) != null) {                        colEntity.setId(f.get(t).toString());                    }                    if (parm.get("pid").equals(f.getName()) && f.get(t) != null) {                        colEntity.setPid(f.get(t).toString());                    }                    if (parm.get("content").equals(f.getName()) && f.get(t) != null) {                        colEntity.setContent(f.get(t).toString());                    }                    if (f.get(t) != null && parm.get("fieldName") != null && parm.get("fieldName").equals(f.getName())) {                        colEntity.setFieldName(f.get(t).toString());                    }                    if (parm.get("width").equals(f.getName()) && f.get(t) != null) {                        colEntity.setWidth(Integer.parseInt(f.get(t).toString()));                    }                }                lc.add(colEntity);            }        }        setParm(lc, rootid); // 处理基础参数        List<ColEntity> s = ExcelTreeUtil.buildByRecursive(lc, rootid); // 构建树结构        setColNum(lc, s);        return s;    }        public static void setParm(List<ColEntity> list, String rootid) {        int row = 0; //excel第几行        int rLen = 0; //excel 跨多少行        int totalRow = ExcelTreeUtil.getMaxStep(list);        int totalCol = ExcelTreeUtil.getDownChildren(list, rootid);        for (int i = 0; i < list.size(); i++) {            ColEntity poit = list.get(i);            int tree_step = ExcelTreeUtil.getTreeStep(list, poit.getPid(), 0);//往上遍历tree            poit.setTreeStep(tree_step);            poit.setRow(tree_step);//设置第几行            //判断是否有节点            boolean hasCh = ExcelTreeUtil.hasChild(list, poit);            poit.setHasChildren(hasCh);            if (hasCh) {                poit.setRLen(0);//设置跨多少行            } else {                if (tree_step < totalRow) {                    rLen = totalRow - tree_step;                }                poit.setRLen(rLen);            }            poit.setTotalRow(totalRow);            poit.setTotalCol(totalCol);        }    }        public static void setColNum(List<ColEntity> list, List<ColEntity> treeList) {        //int col = pcIndex;//excel第几列        //int cLen ;//xcel跨多少列        List<ColEntity> new_list = new ArrayList<>();//新的遍历list        for (int i = 0; i < treeList.size(); i++) {            ColEntity poit = treeList.get(i);            //String temp_id = ExcelTreeUtil.getStepParentId(list,poit.getId() ,1);            int col = ExcelTreeUtil.getParentCol(list, poit.getPid()).getCol();            int brotherCol = ExcelTreeUtil.getBrotherChilNum(list, poit);            poit.setCol(col + brotherCol);            int cLen = ExcelTreeUtil.getDownChildren(list, poit.getId());            if (cLen <= 1) {                cLen = 0;            }            //else  cLen--;            poit.setCLen(cLen);//设置跨多少列            if (poit.getCellList().size() > 0) {                new_list.addAll(poit.getCellList());            }        }        if (new_list.size() > 0) {            setColNum(list, new_list);        }    }}

6、测试

import com.entity.ColEntity;import com.entity.TitleEntity;import com.Google.common.collect.ImmutableMap;import com.util.ExcelPoiUtil;import org.apache.poi.hssf.usermodel.HSSFWorkbook;import java.util.*;public class TestMain {    static Map<String,List<ColEntity>> heads = new HashMap<>();// 最终导出的多个sheet的表头    static Map<String,List<Map<String, String>>> datas = new HashMap<>();// 最终导出的多个sheet的内容    static Map<String,Integer> types = new HashMap<>();// 最终导出的每个sheet的样式类型    static Map<String,List<Integer>> autoRowHeights = new HashMap<>();// 最终导出的每个sheet的需要自适应行高的行号    static Map<String,List<Integer>> mergeIndexs = new HashMap<>();// 最终导出的每个sheet的需要纵向合并的单元格列号    public static void main(String[] args) throws Exception {        单级表头();        多级表头Map();        多级表头Obj();        多级表头Obj1();        多级表头Obj2();        纵向合并单元格();        // 多个sheet导出        ExcelPoiUtil excelTool = new ExcelPoiUtil();        //HSSFWorkbook workbook = excelTool.exportWorkbook(heads, datas, 0, null, null); // 这里多个sheet都用的同一个样式        HSSFWorkbook workbook = excelTool.exportWorkbook(heads, datas, types, null, mergeIndexs);        excelTool.save(workbook,"C:\\Users\\Administrator\\Desktop\\多个sheet.xlsx");    }    public static void 单级表头() throws Exception {        //单级的表头==============================================================        Map<String, String> map = new HashMap<String, String>();        map.put("登录名", "u_login_id");        Map<String, String> map1 = new HashMap<String, String>();        map1.put("用户名", "u_name");        Map<String, String> map2 = new HashMap<String, String>();        map2.put("角色", "u_role");        Map<String, String> map3 = new HashMap<String, String>();        map3.put("部门", "u_dep");        Map<String, String> map4 = new HashMap<String, String>();        map4.put("用户类型", "u_type");        List<Map<String, String>> titleList = new ArrayList<>();        titleList.add(map);        titleList.add(map1);        titleList.add(map2);        titleList.add(map3);        titleList.add(map4);        //单级的 行内数据        List<Map<String, String>> rowList = new ArrayList<>();        for (int i = 0; i < 7; i++) {            Map<String, String> m = new HashMap<String, String>();            m.put("u_login_id", "登录名" + i);            m.put("u_name", "张三" + i);            m.put("u_role", "角色" + i);            m.put("u_dep", "部门" + i);            m.put("u_type", "用户类型" + i);            rowList.add(m);        }        ExcelPoiUtil excelTool = new ExcelPoiUtil("单级表头的表格");        List<ColEntity> titleData = excelTool.colEntityTransformer(titleList);        HSSFWorkbook workbook = excelTool.exportWorkbook(titleData, rowList,1,null);        excelTool.save(workbook,"C:\\Users\\Administrator\\Desktop\\单级表头.xlsx");    }    public static void 多级表头Map() throws Exception {        List<Map<String,String>> titleList=new ArrayList<>();        Map<String,String> titleMap=new HashMap<String,String>();        titleMap.put("id","11");titleMap.put("pid","0");titleMap.put("content","登录名");titleMap.put("fieldName","u_login_id");titleMap.put("width","20");        Map<String,String> titleMap1=new HashMap<String,String>();        titleMap1.put("id","1");titleMap1.put("pid","0");titleMap1.put("content","姓名");titleMap1.put("fieldName","u_name");titleMap1.put("width","20");        Map<String,String> titleMap2=new HashMap<String,String>();        titleMap2.put("id","2");titleMap2.put("pid","0");titleMap2.put("content","角色加部门");titleMap2.put("fieldName",null);titleMap2.put("width","20");        Map<String,String> titleMap3=new HashMap<String,String>();        titleMap3.put("id","3");titleMap3.put("pid","2");titleMap3.put("content","角色");titleMap3.put("fieldName","u_role");titleMap3.put("width","15");        Map<String,String> titleMap4=new HashMap<String,String>();        titleMap4.put("id","4");titleMap4.put("pid","2");titleMap4.put("content","部门");titleMap4.put("fieldName","u_dep");titleMap4.put("width","15");        Map<String,String> titleMap5=new HashMap<String,String>();        titleMap5.put("id","22");titleMap5.put("pid","0");titleMap5.put("content","角色加部门1");titleMap5.put("fieldName",null);titleMap5.put("width","20");        Map<String,String> titleMap6=new HashMap<String,String>();        titleMap6.put("id","22_1");titleMap6.put("pid","22");titleMap6.put("content","角色1");titleMap6.put("fieldName","u_role");titleMap6.put("width","10");        Map<String,String> titleMap7=new HashMap<String,String>();        titleMap7.put("id","22_2");titleMap7.put("pid","22");titleMap7.put("content","部门1");titleMap7.put("fieldName","u_dep");titleMap7.put("width","10");        titleList.add(titleMap); titleList.add(titleMap1); titleList.add(titleMap2); titleList.add(titleMap3); titleList.add(titleMap4);        titleList.add(titleMap5); titleList.add(titleMap6); titleList.add(titleMap7);        // 单级的 行内数据        List<Map<String, String>> rowList = new ArrayList<>();        for (int i = 0; i < 7; i++) {            Map<String, String> m = new HashMap<String, String>();            m.put("u_login_id", "登录名zx" + i);            m.put("u_name", "张三" + i);            m.put("u_role", "角色" + i);            m.put("u_dep", "部门" + i);            m.put("u_type", "用户类型" + i);            rowList.add(m);        }        ExcelPoiUtil excelTool = new ExcelPoiUtil("List);        Map<String,String> param = ImmutableMap.<String, String>builder().put("id", "id").put("pid", "pid")                .put("content", "content").put("fieldName", "fieldName").put("width", "width").build();        List<ColEntity> titleData = excelTool.colEntityTransformer(titleList,param, "0");        //HSSFWorkbook workbook = excelTool.exportWorkbook(titleData, rowList);        //excelTool.save(workbook,"C:\\Users\\Administrator\\Desktop\\多级表头Map.xlsx");        heads.put("List,titleData);// 每个sheet的表头，sheet名称为key        datas.put("List,rowList);// 每个sheet的内容，sheet名称为key        types.put("List,0);// 每个sheet的样式类型，sheet名称为key    }    public static void 多级表头Obj() throws Exception {        List<TitleEntity> titleList = new ArrayList<>();        titleList.add(new TitleEntity("0", null, "总表", null,20));        titleList.add(new TitleEntity("11", "0", "登录名2", "u_login_id",15));        titleList.add(new TitleEntity("1", "0", "姓名", "u_name",15));        titleList.add(new TitleEntity("2", "0", "角色加部门", null,20));        titleList.add(new TitleEntity("3", "2", "角色", "u_role",20));        titleList.add(new TitleEntity("4", "2", "部门", "u_dep",20));        titleList.add(new TitleEntity("33", "0", "角色加部门1", null,15));        titleList.add(new TitleEntity("33_1", "33", "角色33", "u_role",15));        titleList.add(new TitleEntity("33_2", "33_1", "部门33", "u_dep",15));        titleList.add(new TitleEntity("44", "0", "角色加部门2", null,10));        titleList.add(new TitleEntity("44_1", "44", "角色44", "u_role",10));        titleList.add(new TitleEntity("44_2", "44", "部门44", "u_dep",10));        titleList.add(new TitleEntity("1_1", "1", "姓名1", "u_name",15));        titleList.add(new TitleEntity("44_3", "44_2", "44_2", "u_dep",10));        //单级的 行内数据        List<Map<String, String>> rowList = new ArrayList<>();        for (int i = 0; i < 7; i++) {            Map<String, String> m = new HashMap<String, String>();            m.put("u_login_id", "登录名" + i);            m.put("u_name", "张三" + i);            m.put("u_role", "角色" + i);            m.put("u_dep", "部门" + i);            m.put("u_type", "用户类型" + i);            rowList.add(m);        }        ExcelPoiUtil excelTool = new ExcelPoiUtil("实体类（entity）多级表头表格");        Map<String,String> param = ImmutableMap.<String, String>builder().put("id", "id").put("pid", "pid")                .put("content", "content").put("fieldName", "fieldName").put("width", "width").build();        List<ColEntity> titleData = excelTool.colEntityTransformer(titleList, param, "0");        //HSSFWorkbook workbook = excelTool.exportWorkbook(titleData, rowList);        //excelTool.save(workbook,"C:\\Users\\Administrator\\Desktop\\多级表头Obj.xlsx");        heads.put("实体类（entity）多级表头表格",titleData);// 每个sheet的表头，sheet名称为key        datas.put("实体类（entity）多级表头表格",rowList);// 每个sheet的内容，sheet名称为key        types.put("实体类（entity）多级表头表格",0);// 每个sheet的样式类型，sheet名称为key    }    public static void 多级表头Obj1() throws Exception {        List<TitleEntity> titleList = new ArrayList<>();        titleList.add(new TitleEntity("title", null, "这里是title", null,20));        titleList.add(new TitleEntity("一级1", "title", "一级1", null,20));        titleList.add(new TitleEntity("一级2", "title", "一级2", null,20));        titleList.add(new TitleEntity("二级1", "一级1", "二级1", null,20));        titleList.add(new TitleEntity("二级2", "一级2", "二级2", null,20));        titleList.add(new TitleEntity("三级1", "二级1", "三级1", null,20));        titleList.add(new TitleEntity("三级2", "二级2", "三级2", null,20));        titleList.add(new TitleEntity("四级1", "三级1", "四级1", "fieldName1",20));        titleList.add(new TitleEntity("四级2", "三级1", "四级2", "fieldName2",20));        titleList.add(new TitleEntity("四级3", "三级2", "四级3", "fieldName3",20));        titleList.add(new TitleEntity("四级4", "三级2", "四级4", "fieldName4",20));        //单级的 行内数据        List<Map<String, String>> rowList = new ArrayList<>();        for (int i = 0; i < 5; i++) {            Map<String, String> m = new HashMap<String, String>();            m.put("fieldName1", "四级1_" + i);            m.put("fieldName2", "四级2_" + i);            m.put("fieldName3", "四级3_" + i);            m.put("fieldName4", "四级4_" + i);            rowList.add(m);        }        ExcelPoiUtil excelTool = new ExcelPoiUtil("实体类（entity）多级表头表格");        Map<String,String> param = ImmutableMap.<String, String>builder().put("id", "id").put("pid", "pid")                .put("content", "content").put("fieldName", "fieldName").put("width", "width").build();        List<ColEntity> titleData = excelTool.colEntityTransformer(titleList, param, "title");        //HSSFWorkbook workbook = excelTool.exportWorkbook(titleData, rowList);        //excelTool.save(workbook,"C:\\Users\\Administrator\\Desktop\\多级表头Obj1.xlsx");        heads.put("实体类（entity）多级表头表格1",titleData);// 每个sheet的表头，sheet名称为key        datas.put("实体类（entity）多级表头表格1",rowList);// 每个sheet的内容，sheet名称为key        types.put("实体类（entity）多级表头表格1",0);// 每个sheet的样式类型，sheet名称为key    }    public static void 多级表头Obj2() throws Exception {        List<TitleEntity> titleList = new ArrayList<>();        titleList.add(new TitleEntity("title", null, "这里是title", null,20));        // 固定的五项表头        titleList.add(new TitleEntity("项目", "title", "项目", null,20));        titleList.add(new TitleEntity("评分规则", "项目", "评分规则", null,20));        titleList.add(new TitleEntity("评分标准", "评分规则", "评分标准", null,20));        titleList.add(new TitleEntity("所在单位", "评分标准", "所在单位", "unit",15));        titleList.add(new TitleEntity("所在部门", "评分标准", "所在部门", "dept",15));        // 动态表头（实际项目需要根据数据库数据添加）        int count = 0;        for (int i = 0; i < 2; i++) {            String xmId = "项目"+(i+1);            TitleEntity xm = new TitleEntity(xmId, "title", xmId, null, 20);            titleList.add(xm);            for (int j = 0; j < 2; j++) {                String gzId = "项目"+(i+1)+"-"+"规则"+(j+1);                String bzId = "项目"+(i+1)+"-"+"标准"+(j+1);                TitleEntity gz = new TitleEntity(gzId, xmId, gzId, null, 20);                TitleEntity bz = new TitleEntity(bzId, gzId, String.valueOf(j), null, 20);                TitleEntity sl = new TitleEntity(bzId+"_sl"+j, bzId, "数量", "sl"+count, 10);                TitleEntity df = new TitleEntity(bzId+"_df"+j, bzId, "得分", "df"+count, 10);                titleList.add(gz);                titleList.add(bz);                titleList.add(sl);                titleList.add(df);                count++;            }        }        // 填充数据        List<Map<String, String>> rowList = new ArrayList<>();        for (int i = 0; i < 6; i++) {            Map<String, String> m = new HashMap<String, String>();            if (i<4){                m.put("unit", "A单位");                m.put("dept", "部门" + i);            }else {                m.put("unit", "B单位");                m.put("dept", "部门" + i);            }            for (int j = 0; j < count; j++) {                m.put("sl"+j, String.valueOf(j));                m.put("df"+j, String.valueOf(j+i));            }            rowList.add(m);        }        ExcelPoiUtil excelTool = new ExcelPoiUtil("实体类（entity）多级表头表格");        Map<String,String> param = ImmutableMap.<String, String>builder().put("id", "id").put("pid", "pid")                .put("content", "content").put("fieldName", "fieldName").put("width", "width").build();        List<ColEntity> titleData = excelTool.colEntityTransformer(titleList, param, "title");        //HSSFWorkbook workbook = excelTool.exportWorkbook(titleData, rowList,Arrays.asList(0));        //excelTool.save(workbook,"C:\\Users\\Administrator\\Desktop\\多级表头Obj2.xlsx");        heads.put("实体类（entity）多级表头表格2",titleData);// 每个sheet的表头，sheet名称为key        datas.put("实体类（entity）多级表头表格2",rowList);// 每个sheet的内容，sheet名称为key        types.put("实体类（entity）多级表头表格2",0);// 每个sheet的样式类型，sheet名称为key        mergeIndexs.put("实体类（entity）多级表头表格2",Arrays.asList(0));// 每个sheet的默认行高，sheet名称为key    }    public static void 纵向合并单元格() throws Exception {        List<Map<String,String>> titleList=new ArrayList<>();        Map<String,String> titleMap=new HashMap<String,String>();        titleMap.put("id","11");titleMap.put("pid","0");titleMap.put("content","登录名");titleMap.put("fieldName","u_login_id");titleMap.put("width","20");        Map<String,String> titleMap1=new HashMap<String,String>();        titleMap1.put("id","1");titleMap1.put("pid","0");titleMap1.put("content","姓名");titleMap1.put("fieldName","u_name");titleMap1.put("width","20");        Map<String,String> titleMap2=new HashMap<String,String>();        titleMap2.put("id","2");titleMap2.put("pid","0");titleMap2.put("content","角色加部门");titleMap2.put("fieldName",null);titleMap2.put("width","20");        Map<String,String> titleMap3=new HashMap<String,String>();        titleMap3.put("id","3");titleMap3.put("pid","2");titleMap3.put("content","角色");titleMap3.put("fieldName","u_role");titleMap3.put("width","15");        Map<String,String> titleMap4=new HashMap<String,String>();        titleMap4.put("id","4");titleMap4.put("pid","2");titleMap4.put("content","部门");titleMap4.put("fieldName","u_dep");titleMap4.put("width","15");        Map<String,String> titleMap5=new HashMap<String,String>();        titleMap5.put("id","22");titleMap5.put("pid","0");titleMap5.put("content","角色加部门1");titleMap5.put("fieldName",null);titleMap5.put("width","20");        Map<String,String> titleMap6=new HashMap<String,String>();        titleMap6.put("id","22_1");titleMap6.put("pid","22");titleMap6.put("content","角色1");titleMap6.put("fieldName","u_role");titleMap6.put("width","10");        Map<String,String> titleMap7=new HashMap<String,String>();        titleMap7.put("id","22_2");titleMap7.put("pid","22");titleMap7.put("content","部门1");titleMap7.put("fieldName","u_dep");titleMap7.put("width","10");        titleList.add(titleMap); titleList.add(titleMap1); titleList.add(titleMap2); titleList.add(titleMap3); titleList.add(titleMap4);        titleList.add(titleMap5); titleList.add(titleMap6); titleList.add(titleMap7);        // 单级的 行内数据        List<Map<String, String>> rowList = new ArrayList<>();        for (int i = 0; i < 10; i++) {            Map<String, String> m = new HashMap<String, String>();            m.put("u_login_id", "登录名zx" + i);            if (i<6){                m.put("u_login_id", "登录名zx1");                m.put("u_name", i<3?"张三":"李四");            }else {                m.put("u_login_id", "登录名zx2");                m.put("u_name", i<9?"王五":"赵六");            }            m.put("u_role", "角色" + i);            m.put("u_dep", "部门" + i);            m.put("u_type", "用户类型" + i);            rowList.add(m);        }        ExcelPoiUtil excelTool = new ExcelPoiUtil("纵向合并单元格");        Map<String,String> param = ImmutableMap.<String, String>builder().put("id", "id").put("pid", "pid")                .put("content", "content").put("fieldName", "fieldName").put("width", "width").build();        List<ColEntity> titleData = excelTool.colEntityTransformer(titleList,param, "0");        //HSSFWorkbook workbook = excelTool.exportWorkbook(titleData, rowList,Arrays.asList(0,1));        //excelTool.save(workbook,"C:\\Users\\Administrator\\Desktop\\纵向合并单元格.xlsx");        heads.put("纵向合并单元格",titleData);// 每个sheet的表头，sheet名称为key        datas.put("纵向合并单元格",rowList);// 每个sheet的内容，sheet名称为key        types.put("纵向合并单元格",0);// 每个sheet的样式类型，sheet名称为key        mergeIndexs.put("纵向合并单元格",Arrays.asList(0,1));// 每个sheet的默认行高，sheet名称为key    }}

最后

以上，终于是把项目里要的表格给导出来了！😎

实现代码的结构如图：

源码在这

最后感谢 这篇文章 的作者，也感谢这文章评论区提出bug的用户🥰

来源地址：https://blog.csdn.net/weixin_43165220/article/details/129521524