Springboot+POI实现excel生成下载进阶版（单元格合并，多Sheet,各种样式处理）

 上周五来了新的需求，基本上我写的还款那一系列流程不要了（我好悲伤，当时写了很久的，逻辑复杂的写的我很骄傲），新的变成如上所示（仅仅一部分），勾选几笔后生成一个excel表格，不同的融资编号所引发的那堆数据生成的表格放在不同的sheet页。模板如下：

 　　哎呦，这个表格不太规则哟~之前写的比较简单，中规中矩，一行字段标题对应几行数据，连表头都没有，但这个是双重表格，而且有16个以上的合并单元格，表格带边框，左对齐，右对齐，居中的数据都有，还有加粗的，大小不一的数据，一看写出代码就少不了。于是最开始的想法是偷个懒，坐等同事的在上一步业务中对每笔单号生成各自的excel，我在这一步拿着所有的融资编号去找到他们在上一步保存的excel，然后写套代码做一个excel的数据合并，将不同的excel合到一个excel中，放入不同sheet页（来夸夸我，我是不是很机智），结果我成功了，但我又失败了。。。我在网上找了套代码进行合并的，然后无脑的修改后还是运行，生成本地成功了，但是放在swagger上测试下载时，一直说文件打不开。。整到下班也一直说格式问题文件打不开，网上各种方式都试了，，果然，别人的代码不要随意套用，还是自己写一套比较实用。

　　周末的日子比较无聊，望着空荡荡的房子，安静的过分，无聊的我决定找点事情做，打开电脑打开IDEA，将周五决定偷懒的工作整一下，于是各种通过代码调整合并单元格，样式诸类。。。基本上把整个思路全写完了，大面积代码，剩下的就是那些数据在哪取我不清楚，只能先造点假数据了。。周一来了后，问了下同事数据取的表在哪，然后把代码补充下，再根据生成的excel样式对比模板表，调了调，大功告成。因为第一次处理生成这种样式的excel，所以纪念一下，有需要的朋友可以当个参考，注释我都写的很明确了，因为我在main方法里面加个测试数据，所以代码粘下来可以直接运行看效果。

代码如下：

package cn.exrick.xboot.common.utils;

import org.apache.poi.hssf.usermodel.*;
import org.apache.poi.ss.util.CellRangeAddress;
import javax.servlet.http.HttpServletResponse;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.io.UnsupportedEncodingException;
import java.text.SimpleDateFormat;
import java.util.*;

/**
 * @author zae
 */
public class DownLoadPayMsgUtil {

    public static void main(String[] args) {
        //示例数据：
        //申请信息数据
        String[] apllyTitlesKey = new String[]{"txn_no","deliver_contact","order_id","order_date","deliver_address","account_period","commodity_name","trade_amount"};
        String[] applyTitle = new String[]{"序号","产融平台融资编号","发货人","订单编号","订单日期","工厂地址","收货地址","商品名称","运费金额"};
        Map<String, Object> randomMapOne = getRandomMap(apllyTitlesKey);
        Map<String, Object> randomMapTwo = getRandomMap(apllyTitlesKey);
        Map<String, Object> randomMapThree = getRandomMap(apllyTitlesKey);
        Map<String, Object> randomMapFour = getRandomMap(apllyTitlesKey);
        List<Map<String,Object>> applyContantList = Arrays.asList(randomMapOne,randomMapTwo,randomMapThree,randomMapFour);//实际工作中在数据库中获取
        String[][] applyContent = DownLoadPayMsgUtil.convertListToArray(apllyTitlesKey, applyContantList);//list转换二维数组

        //支付信息数据
        String[] payTitlesKey = new String[]{"carry_date","carry_no","carry_contact_user","carry_plate","carry_amount","account_bank","account_no"};
        String[] payTitle = new String[]{"承运时间","提单号","承运人","承运车号","运费金额","开户行","账号"};
        Map<String, Object> mapOne = getRandomMap(payTitlesKey);
        Map<String, Object> mapTwo = getRandomMap(payTitlesKey);
        List<Map<String,Object>> payContantList = Arrays.asList(mapOne,mapTwo);//实际工作中在数据库中获取
        String[][] payContent = DownLoadPayMsgUtil.convertListToArray(payTitlesKey, payContantList);//list转换二维数组

        //前置内容数据
        List<String> beforeTitle = Arrays.asList("申请人:","开户行:","名称:","账号:");
        List<String> beforeContent = Arrays.asList("zae","工商银行","zae的账户","274630575");//实际工作在数据库中取得

        Map<String,Object> dataMap = new HashMap<>();
        dataMap.put("applyTitle",applyTitle);//申请单表字段组
        dataMap.put("applyContent",applyContent);//申请单表内容数据
        dataMap.put("payTitle",payTitle);//支付信息表字段组
        dataMap.put("payContent",payContent);//支付信息表内容数据
        dataMap.put("beforeTitle",beforeTitle);//前置内容字段组
        dataMap.put("beforeContent",beforeContent);//前置内容数据
        dataMap.put("applyAmount","2000");//申请金额总和
        dataMap.put("payAmount","3000");//运费金额总和

        List<Map<String,Object>> dataList = new ArrayList<>();
        Map<String,Object> dataMap2 = new HashMap<>(dataMap);
        dataList.add(dataMap);//多个map情况下会生成多个sheet页
        dataList.add(dataMap2);

        //根据传入的数据，生成一个excel对象
        HSSFWorkbook wb = DownLoadPayMsgUtil.getHSSFWorkbook(dataList);
        //导出下载
        //DownLoadPayMsgUtil.exportExcel(wb,"提款申请.xls",null);
        //保存在本地
        exportExcelToLocally(wb,"D:\提款申请.xls");

    }


    /**
     * 用传入的sheet名称，标题，内容生成HSSFWorkbook对象。
     * @param dataList
     * @return HSSFWorkbook
     */
    public static HSSFWorkbook getHSSFWorkbook(List<Map<String,Object>> dataList){
        // 第一步，创建一个HSSFWorkbook，对应一个Excel文件
        HSSFWorkbook wb = new HSSFWorkbook();
        //第二步，创建确定位置的的合并单元格对象
        CellRangeAddress callRangeAddress1 = new CellRangeAddress(2,2,0,8);//起始行,结束行,起始列,结束列
        CellRangeAddress callRangeAddress2 = new CellRangeAddress(3,3,0,1);//起始行,结束行,起始列,结束列
        CellRangeAddress callRangeAddress3 = new CellRangeAddress(3,3,2,5);//起始行,结束行,起始列,结束列
        CellRangeAddress callRangeAddress4 = new CellRangeAddress(3,3,7,8);//起始行,结束行,起始列,结束列
        CellRangeAddress callRangeAddress5 = new CellRangeAddress(4,4,0,1);//起始行,结束行,起始列,结束列
        CellRangeAddress callRangeAddress6 = new CellRangeAddress(4,4,2,7);//起始行,结束行,起始列,结束列
        CellRangeAddress callRangeAddress7 = new CellRangeAddress(5,5,0,1);//起始行,结束行,起始列,结束列
        CellRangeAddress callRangeAddress8 = new CellRangeAddress(5,5,2,7);//起始行,结束行,起始列,结束列
        CellRangeAddress callRangeAddress9 = new CellRangeAddress(6,6,0,1);//起始行,结束行,起始列,结束列
        CellRangeAddress callRangeAddress10 = new CellRangeAddress(6,6,2,7);//起始行,结束行,起始列,结束列
        CellRangeAddress callRangeAddress11 = new CellRangeAddress(8,8,0,8);//起始行,结束行,起始列,结束列

        // 第三步，创建单元格样式（字体大小，是否加粗，是否加边框,对齐方式）
        HSSFCellStyle styleTitle = createCellStyle(wb,(short)11,true,false,"C");//标题头
        HSSFCellStyle styleBeforeTitle = createCellStyle(wb,(short)9,false,false,"R");//前置内容字段
        HSSFCellStyle styleBeforeData = createCellStyle(wb,(short)9,false,false,"F");//前置内容数据
        HSSFCellStyle styleTableTitle = createCellStyle(wb,(short)9,true,true,"C");//表头
        HSSFCellStyle styleTableContent = createCellStyle(wb,(short)9,false,true,"C");//表内容


        for(int k=1;k<=dataList.size();k++){
            Map<String,Object> dataMap = dataList.get(k-1);
            String []applyTitle = (String[]) dataMap.get("applyTitle");//申请信息表的字段组
            String [][]applyContent = (String[][]) dataMap.get("applyContent");//申请信息表的内容组
            String []payTitle = (String[]) dataMap.get("payTitle");//支付信息表的字段组
            String [][]payContent = (String[][]) dataMap.get("payContent");//支付信息表的内容组
            //第四步：创建未确定位置的合并单元格对象
            CellRangeAddress callRangeAddress12 = new CellRangeAddress(10+applyContent.length,10+applyContent.length,0,4);//起始行,结束行,起始列,结束列
            CellRangeAddress callRangeAddress13 = new CellRangeAddress(10+applyContent.length,10+applyContent.length,6,7);//起始行,结束行,起始列,结束列
            CellRangeAddress callRangeAddress14 = new CellRangeAddress(11+applyContent.length,11+applyContent.length,0,8);//起始行,结束行,起始列,结束列
            CellRangeAddress callRangeAddress15 = new CellRangeAddress(12+applyContent.length,12+applyContent.length,6,8);//起始行,结束行,起始列,结束列
            // 第五步，在workbook中添加一个sheet,对应Excel文件中的sheet
            HSSFSheet sheet = wb.createSheet("Sheet"+k);
            //设置列宽
            sheet.setColumnWidth(0, 256*15);
            sheet.setColumnWidth(1, 256*20);
            sheet.setColumnWidth(2, 256*25);
            sheet.setColumnWidth(5, 256*30);
            //第六步，加载合并单元格对象
            sheet.addMergedRegion(callRangeAddress1);
            sheet.addMergedRegion(callRangeAddress2);
            sheet.addMergedRegion(callRangeAddress3);
            sheet.addMergedRegion(callRangeAddress4);
            sheet.addMergedRegion(callRangeAddress5);
            sheet.addMergedRegion(callRangeAddress6);
            sheet.addMergedRegion(callRangeAddress7);
            sheet.addMergedRegion(callRangeAddress8);
            sheet.addMergedRegion(callRangeAddress9);
            sheet.addMergedRegion(callRangeAddress10);
            sheet.addMergedRegion(callRangeAddress11);
            sheet.addMergedRegion(callRangeAddress12);
            sheet.addMergedRegion(callRangeAddress13);
            sheet.addMergedRegion(callRangeAddress14);
            sheet.addMergedRegion(callRangeAddress15);
            for(int i = 1;i<=payContent.length+1;i++){//支付信息账号部分单元格合并的创建以及加载
                CellRangeAddress callRangeAddress16 = new CellRangeAddress(12+applyContent.length+i,12+applyContent.length+i,6,8);//起始行,结束行,起始列,结束列
                sheet.addMergedRegion(callRangeAddress16);
            }

            // 第七步，根据模板往sheet中添加数据
            //7.1 设置标题头和前置内容
            List<String> beforeTitle = (List<String>) dataMap.get("beforeTitle");
            List<String> beforeContent = (List<String>) dataMap.get("beforeContent");
            //设置总标题
            HSSFRow rowTitle = sheet.createRow(2);
            HSSFCell cellTitle = rowTitle.createCell(0);
            cellTitle.setCellStyle(styleTitle);
            cellTitle.setCellValue("提款信息表");
            //设置前置内容数据
            for(int i = 3;i<=6;i++){
                HSSFRow rowBefore = sheet.createRow(i);
                for(int j = 0;j<=2;j++){//循环赋值前置信息数据（排除申请日期）
                    if(j == 1){
                        continue;
                    }
                    HSSFCell cellBefore = rowBefore.createCell(j);
                    if(j == 0){
                        cellBefore.setCellStyle(styleBeforeTitle);
                        cellBefore.setCellValue(beforeTitle.get(i-3));
                    }else{
                        cellBefore.setCellStyle(styleBeforeData);
                        cellBefore.setCellValue(beforeContent.get(i-3));
                    }
                }
                if(i == 3){//申请日期
                    HSSFCell cellBeforeDate = rowBefore.createCell(7);
                    cellBeforeDate.setCellStyle(styleBeforeData);
                    cellBeforeDate.setCellValue("申请日期:"+new SimpleDateFormat("yyyy-MM-dd").format(new Date()));
                }

            }

            //7.2申请信息
            //设置申请信息表的表头
            HSSFRow rowApplyTitle = sheet.createRow(8);
            for(int i = 0;i<applyTitle.length;i++){
                HSSFCell cellApplyTitle = rowApplyTitle.createCell(i);
                cellApplyTitle.setCellStyle(styleTableTitle);
                cellApplyTitle.setCellValue("申请信息");
            }

            //设置申请信息表的内容
            for(int row = 9;row <= 9+applyContent.length;row++){
                HSSFRow rowApplyContent = sheet.createRow(row);
                for(int cell = 0;cell<applyTitle.length;cell++){
                    HSSFCell cellApplyContent = rowApplyContent.createCell(cell);
                    cellApplyContent.setCellStyle(styleTableContent);
                    if(row == 9){//表的字段名
                        cellApplyContent.setCellValue(applyTitle[cell]);
                    }else if(row != 9 && cell == 0){//表的序号列
                        cellApplyContent.setCellValue(row-9);
                    }else{//表的内容
                        cellApplyContent.setCellValue(applyContent[row-10][cell-1]);
                    }
                }
            }
            //设置申请信息表的底部
            HSSFRow rowApplyBottom = sheet.createRow(9+applyContent.length+1);
            for(int i = 0;i<=8;i++){
                if(i==0 || i==5 || i==6 || i==8){
                    HSSFCell cellApplyBottom = rowApplyBottom.createCell(i);
                    cellApplyBottom.setCellStyle(styleTableContent);
                    if(i == 8){
                        cellApplyBottom.setCellValue(dataMap.get("applyAmount").toString());
                    }
                }
            }

            //7.3支付信息
            //设置支付信息表的表头
            HSSFRow rowPayTitle = sheet.createRow(11+applyContent.length);
            for(int i = 0;i<applyTitle.length;i++){
                HSSFCell cellPayTitle = rowPayTitle.createCell(i);
                cellPayTitle.setCellStyle(styleTableTitle);
                cellPayTitle.setCellValue("支付信息");
            }
            //设置支付信息表的内容
            for(int row = 12+applyContent.length;row<=12+applyContent.length+payContent.length+1;row++){
                HSSFRow rowPayContent = sheet.createRow(row);
                for(int cell = 0;cell<payTitle.length-1;cell++){
                    HSSFCell cellPayContent = rowPayContent.createCell(cell);
                    cellPayContent.setCellStyle(styleTableContent);
                    if(row == 12+applyContent.length){//支付信息表的字段名
                        cellPayContent.setCellValue(payTitle[cell]);
                    }else if(row == 12+applyContent.length+payContent.length+1){//支付信息表的最后一行
                        if(cell == 4){//运费金额总和
                            cellPayContent.setCellValue(dataMap.get("payAmount").toString());
                        }else{//空白
                            cellPayContent.setCellValue("");
                        }
                    }else{//支付信息表的内容
                        cellPayContent.setCellValue(payContent[row-13-applyContent.length][cell]);
                    }
                }
                for(int cell = payTitle.length-1;cell<9;cell++){//关于该表中账号字段的特殊处理
                    HSSFCell cellPayContent = rowPayContent.createCell(cell);
                    cellPayContent.setCellStyle(styleTableContent);
                    if(row == 12+applyContent.length){
                        cellPayContent.setCellValue(payTitle[payTitle.length-1]);
                    }else if(row == 12+applyContent.length+payContent.length+1){
                        cellPayContent.setCellValue("");
                    }else{
                        cellPayContent.setCellValue(payContent[row-13-applyContent.length][payTitle.length-1]);
                    }
                }
            }
        }
        return wb;
    }

    //把list转换为String[][]
    public static String[][] convertListToArray(String[] titles , List<Map<String,Object>> list){
        //excel的主体内容
        String[][] content = new String[list.size()][];

        for (int i = 0; i < list.size(); i++) {
            Map<String,Object> map = list.get(i);
            content[i] = new String[titles.length];
            for (int j = 0; j < titles.length; j++) {
                Object obj = map.get(titles[j]);
                if(obj == null){
                    obj = "";
                }
                content[i][j] =  obj.toString();
            }
        }
        return content;
    }

    /**
     *字体大小，是否加粗，是否水平居中，是否加边框,左对齐"L",右对齐"R"
     * @param workbook
     * @param fontsize
     * @return 单元格样式
     */
    private static HSSFCellStyle createCellStyle(HSSFWorkbook workbook, short fontsize,boolean flag,boolean flag2,String alignType) {
        HSSFCellStyle style = workbook.createCellStyle();
        //左右对齐
        if(alignType!=null){
            if("L".equalsIgnoreCase(alignType)){
                style.setAlignment(HSSFCellStyle.ALIGN_LEFT);//左对齐
            }else if("R".equalsIgnoreCase(alignType)){
                style.setAlignment(HSSFCellStyle.ALIGN_RIGHT);//右对齐
            }else if("C".equalsIgnoreCase(alignType)){
                style.setAlignment(HSSFCellStyle.ALIGN_CENTER);//水平居中
            }
        }
        //是否加边框
        if(flag2){
            style.setBorderBottom(HSSFCellStyle.BORDER_THIN); //下边框
            style.setBorderLeft(HSSFCellStyle.BORDER_THIN);//左边框
            style.setBorderTop(HSSFCellStyle.BORDER_THIN);//上边框
            style.setBorderRight(HSSFCellStyle.BORDER_THIN);//右边框
        }

        style.setVerticalAlignment(HSSFCellStyle.VERTICAL_CENTER);//垂直居中
        //创建字体
        HSSFFont font = workbook.createFont();
        //是否加粗字体
        if(flag){
            font.setBoldweight(HSSFFont.BOLDWEIGHT_BOLD);
        }
        font.setFontHeightInPoints(fontsize);
        //加载字体
        style.setFont(font);
        return style;
    }

    /*
       把HSSFWorkbook对象写入到浏览器输出流，完成下载功能
    */
    public static void exportExcel(HSSFWorkbook hssfWorkbook, String fileName, HttpServletResponse response){

        try {
            //设置响应头
            DownLoadPayMsgUtil.setResponseHeader(response, fileName);
            //获取输出流
            OutputStream os = response.getOutputStream();
            //写入
            hssfWorkbook.write(os);
            os.flush();
            os.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    /*
    设置浏览器下载响应头
     */
    private static void setResponseHeader(HttpServletResponse response, String fileName) {
        try {
            try {
                fileName = new String(fileName.getBytes(),"ISO8859-1");
            } catch (UnsupportedEncodingException e) {
                e.printStackTrace();
            }
            response.setContentType("application/octet-stream;charset=UTF-8");
            response.setHeader("Content-Disposition", "attachment;filename="+ fileName);
            response.addHeader("Pargam", "no-cache");
            response.addHeader("Cache-Control", "no-cache");
        } catch (Exception ex) {
            ex.printStackTrace();
        }
    }

    /**
     * 将生成的excel生成在本地
     * @param hssfWorkbook
     * @param path
     */
    private static void exportExcelToLocally(HSSFWorkbook hssfWorkbook,String path){
        try {
            FileOutputStream fileOut = new FileOutputStream(path);
            hssfWorkbook.write(fileOut);
            fileOut.flush();
            fileOut.close();
            System.out.println("生成成功");
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    /**
     * 随机生成map数据，测试专用
     * @param titleArr
     * @return
     */
    private static Map<String,Object> getRandomMap(String [] titleArr){
        Map<String,Object> rtnMap = new HashMap<>();
        for(int i = 0;i<titleArr.length;i++){
            rtnMap.put(titleArr[i],"测试数据"+i);
        }
        return rtnMap;
    }
}

生成的效果如下：

 生成了两个sheet页，当然如果勾选更多笔融资编号，就会生成更多的sheet页。

注释很清楚，不多解释了，嘻嘻。