<dependencies>
        <dependency>
            <groupId>org.apache.poi</groupId>
            <artifactId>poi</artifactId>
            <version>3.9</version>
        </dependency>
        <dependency>
            <groupId>org.apache.poi</groupId>
            <artifactId>poi-ooxml</artifactId>
            <version>3.9</version>
        </dependency>
        <dependency>
            <groupId>org.apache.poi</groupId>
            <artifactId>poi-ooxml-schemas</artifactId>
            <version>3.9</version>
        </dependency>
    </dependencies>

public class WriterExcel {
    public static void main(String[] args) {
        // 1. 创建工作簿
        XSSFWorkbook workbook = new XSSFWorkbook();
        // 2. 创建工作表
        XSSFSheet sheet = workbook.createSheet("WriterDataTest");
        // 3. 模拟待写入数据
        Map<String,Object[]> data = new TreeMap<>();
        data.put("1", new Object[] {"ID", "NAME", "LASTNAME"});
        data.put("2", new Object[] {1, "Amit", "Shukla"});
        data.put("3", new Object[] {2, "Lokesh", "Gupta"});
        data.put("4", new Object[] {3, "John", "Adwards"});
        data.put("5", new Object[] {4, "Brian", "Schultz"});
        //4. 遍历数据写入表中
        Set<String> keySet = data.keySet();
        int rowNum = 0;
        for (String key : keySet){
            Row row = sheet.createRow(rowNum++);
            Object [] objArr = data.get(key);
            int cellNum = 0;
            for (Object obj: objArr){
                Cell cell  = row.createCell(cellNum++);
                if (obj instanceof String){
                    cell.setCellValue((String)obj);
                }else if(obj instanceof Integer){
                    cell.setCellValue((Integer)obj);
                }
            }
        }
        try {
            File file = new File("Test.xlsx");
            FileOutputStream out = new FileOutputStream(file);
            workbook.write(out);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

public class ReadExcel {
    public static void main(String[] args) {
        try {
            FileInputStream file = new FileInputStream(new File("Test.xlsx"));
            //使用Test.xlsx文件创建工作簿对象
            XSSFWorkbook workbook = new XSSFWorkbook(file);
            //获取第一个sheet内容
            XSSFSheet sheet = workbook.getSheetAt(0);
            // 逐行遍历
            Iterator<Row> rowIterable = sheet.iterator();
            while (rowIterable.hasNext()){
                Row row = rowIterable.next();
                // 逐列遍历
                Iterator<Cell> cellIterator = row.cellIterator();
                while (cellIterator.hasNext()){
                    Cell cell = cellIterator.next();
                    switch (cell.getCellType()){
                        case Cell.CELL_TYPE_NUMERIC:
                            System.out.println(cell.getNumericCellValue() + "t");
                            break;
                        case Cell.CELL_TYPE_STRING:
                            System.out.println(cell.getStringCellValue() + "t");
                            break;
                    }
                }
                System.out.println("");
            }
            file.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

public class FormulaExcel {
    public static void main(String[] args) {
        XSSFWorkbook workbook = new XSSFWorkbook();
        XSSFSheet sheet = workbook.createSheet("CalcSimple");

        Row header = sheet.createRow(0);
        header.createCell(0).setCellValue("箱数");
        header.createCell(1).setCellValue("单价");
        header.createCell(2).setCellValue("个数");
        header.createCell(3).setCellValue("总价格");


        Row dataRow = sheet.createRow(1);
        dataRow.createCell(0).setCellValue(10);
        dataRow.createCell(1).setCellValue(2.5);
        dataRow.createCell(2).setCellValue(10);
        dataRow.createCell(3).setCellFormula("A2*B2*C2");
        FileOutputStream out = null;
        try {
            out = new FileOutputStream(new File("formulaTest.xlsx"));
            workbook.write(out);
            out.close();
            System.out.println("Excel with formula cells written successfully");
        } catch (Exception e) {
            e.printStackTrace();
        }
       }
}

public class ReadWithFormula {

    public static void main(String[] args) {
        XSSFWorkbook workbook = new XSSFWorkbook();

        try {
            FileInputStream file  = new FileInputStream(new File("formulaTest.xlsx"));
            FormulaEvaluator evaluator = workbook.getCreationHelper().createFormulaEvaluator();

            XSSFSheet sheet = workbook.getSheetAt(0);
            // 遍历Row
            Iterator<Row> rowIterator = sheet.iterator();
            while (rowIterator.hasNext()){
                Row row = rowIterator.next();
                // 遍历Cell
                Iterator<Cell> cellIterator = row.cellIterator();
                while (cellIterator.hasNext()){
                    Cell cell = cellIterator.next();
                    switch (evaluator.evaluateInCell(cell).getCellType()){
                        case Cell.CELL_TYPE_NUMERIC:
                            System.out.println(cell.getNumericCellValue() + "tt");
                            break;
                        case Cell.CELL_TYPE_STRING:
                            System.out.println(cell.getStringCellValue() + "tt");
                            break;
                        case Cell.CELL_TYPE_FORMULA:
                            break;
                    }
                }
                System.out.println("");
            }
            file.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

public class FomatExcel {
    public static final Integer NUM = 100;
    public static void main(String[] args) throws Exception {
        XSSFWorkbook workbook = new XSSFWorkbook();
        XSSFSheet sheet = workbook.createSheet("单元格样式");
        formatByValue(sheet);
        FileOutputStream out = new FileOutputStream("styleDemo.xlsx");
        workbook.write(out);
        out.close();
    }

    public static  void  formatByValue(Sheet sheet){
        Random random = new Random();
        for (int i = 0; i < NUM; i++) {
            sheet.createRow(i).createCell(0).setCellValue(random.nextInt(100));
        }
        // 获取格式化对象
        SheetConditionalFormatting conditionalFormatting = sheet.getSheetConditionalFormatting();
        //设置格式化条件，条件1
        ConditionalFormattingRule rule1 = conditionalFormatting.createConditionalFormattingRule(ComparisonOperator.GT,"70");
        PatternFormatting patternFormatting1  = rule1.createPatternFormatting();
        patternFormatting1 .setFillBackgroundColor(IndexedColors.BLUE.index);
        patternFormatting1.setFillPattern(PatternFormatting.SOLID_FOREGROUND);

        // 条件2
        ConditionalFormattingRule rule2 = conditionalFormatting.createConditionalFormattingRule(ComparisonOperator.LT,"50");
        PatternFormatting patternFormatting2  = rule2.createPatternFormatting();
        patternFormatting2 .setFillBackgroundColor(IndexedColors.RED.index);
        patternFormatting2.setFillPattern(PatternFormatting.SOLID_FOREGROUND);

        // 列格式范围
        CellRangeAddress[] range = {
                CellRangeAddress.valueOf("A1:A100")
        };
        conditionalFormatting.addConditionalFormatting(range,rule1,rule2);
    }
}

    public static void formatByColor(Sheet sheet) {
        SheetConditionalFormatting sheetCF = sheet.getSheetConditionalFormatting();
        ConditionalFormattingRule rule = sheetCF.createConditionalFormattingRule("MOD(ROW(),2)");
        PatternFormatting fill = rule.createPatternFormatting();
        fill.setFillBackgroundColor(IndexedColors.LIGHT_GREEN.index);
        fill.setFillPattern(PatternFormatting.SOLID_FOREGROUND);

        CellRangeAddress[] regions = {
                CellRangeAddress.valueOf("A1:Z100")
        };
        sheetCF.addConditionalFormatting(regions, rule);
        sheet.createRow(0).createCell(1).setCellValue("交替行变色，绿色填充");
        sheet.createRow(1).createCell(1).setCellValue("条件：MOD(ROW(),2)");
    }
}

    public static void expiryInNext30Days(Sheet sheet)
    {
        CellStyle style = sheet.getWorkbook().createCellStyle();
        style.setDataFormat((short)BuiltinFormats.getBuiltinFormat("d-mmm"));

        sheet.createRow(0).createCell(0).setCellValue("日期");
        sheet.createRow(1).createCell(0).setCellFormula("TODAY()+29");
        sheet.createRow(2).createCell(0).setCellFormula("A2+1");
        sheet.createRow(3).createCell(0).setCellFormula("A3+1");

        for(int rownum = 1; rownum <= 3; rownum++) sheet.getRow(rownum).getCell(0).setCellStyle(style);

        SheetConditionalFormatting sheetCF = sheet.getSheetConditionalFormatting();

        ConditionalFormattingRule rule1 = sheetCF.createConditionalFormattingRule("AND(A2-TODAY()>=0,A2-TODAY()<=30)");
        FontFormatting font = rule1.createFontFormatting();
        font.setFontStyle(false, true);
        font.setFontColorIndex(IndexedColors.BLUE.index);

        CellRangeAddress[] regions = {
                CellRangeAddress.valueOf("A2:A4")
        };

        sheetCF.addConditionalFormatting(regions, rule1);

        sheet.getRow(0).createCell(1).setCellValue("样式将在30后到期");
    }
}

 @PostMapping("user/export")
    @ResponseBody
    @ApiOperation(value="导出用户", httpMethod = "POST",produces="application/json",notes = "导出用户")
    public ResultBean  exportUser(HttpServletResponse response) throws IOException{
        List<SysUser> userList =  sysUserService.getUserList(); // 获取用户数据
        Map<String, String> fieldMap = new LinkedHashMap<String, String>(); // 数据列信息
    	fieldMap.put("id", "编号");
     	fieldMap.put("name", "姓名");
     	fieldMap.put("pwd", "密码");
     	fieldMap.put("tel", "电话");
     	fieldMap.put("code", "编码");
     	fieldMap.put("comment", "备注");
        XSSFWorkbook workbook = new XSSFWorkbook(); // 新建工作簿对象
        XSSFSheet sheet = workbook.createSheet("UserList");// 创建sheet
        int rowNum = 0;
        Row row =  sheet.createRow(rowNum);// 创建第一行对象,设置表标题
        Cell cell;
        int cellNum = 0;
        for (String name:fieldMap.values()){
            cell = row.createCell(cellNum);
            cell.setCellValue(name);
            cellNum++;
        }
        int rows = 1;
         for (SysUser user: userList){//遍历数据插入excel中
            row = sheet.createRow(rows);
            int col = 0;
            row.createCell(col).setCellValue(user.getId()); // 编号id
            row.createCell(col+1).setCellValue(user.getName()); // 姓名Name
            row.createCell(col+2).setCellValue(user.getPwd()); // 密码pwd
            row.createCell(col+3).setCellValue(user.getTel()); // 电话tel
            row.createCell(col+4).setCellValue(user.getCode()); // 编码
            row.createCell(col+5).setCellValue(user.getComment()); // 备注comment
            rows++;
        }
        String fileName = "userInfo";
        OutputStream out =null;
        try {
            out = response.getOutputStream();
            response.reset();
            response.addHeader("Content-Disposition", "attachment; filename=" + fileName + ".xlsx");
            response.setContentType("application/vnd.ms-excel;charset=utf-8");
            workbook.write(out);
        } catch (Exception e) {
            e.printStackTrace();
        }finally {
            out.flush();
            out.close();
        }
        return ResultBean.success();
    }

  		<dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-freemarker</artifactId>
        </dependency>

  #    设置freemarker
  freemarker:
    allow-request-override: false
    #    开发过程建议关闭缓存
    cache: true
    check-template-location: false
    charset: UTF-8
    content-type: text/html; charset=utf-8
    expose-request-attributes: false
    expose-session-attributes: false
    expose-spring-macro-helpers: false
    request-context-attribute:
    # 默认后缀就是.ftl
    suffix: .ftl
    template-loader-path: classPath:/templates/code/    

    @PostMapping("user/doc")
    @ResponseBody
    @ApiOperation(value="导出用户doc", httpMethod = "POST",produces="application/json",notes = "导出用户doc")
    public ResultBean exportDoc() throws  IOException{
        Configuration configuration = new Configuration();
        configuration.setDefaultEncoding("utf-8");
        configuration.setClassForTemplateLoading(this.getClass(), "/templates/code");
        Template template = configuration.getTemplate("UserInfo.ftl");
        Map<String, Object> dataMap = new HashMap<>();
        dataMap.put("name","gaolei");
        dataMap.put("id","02201");
        dataMap.put("code","251525v");
        dataMap.put("pwd","root");
        dataMap.put("tel","08583552");
        File outFile = new File("UserInfoTest.doc");
        Writer out = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(outFile),"UTF-8"));
        try {
            template.process(dataMap,out);
            out.flush();
            out.close();
        } catch (TemplateException e) {
            e.printStackTrace();
        }
        return ResultBean.success();
    }

	@PostMapping("user/requireInfo")
    @ResponseBody
    @ApiOperation(value="导出用户确认信息表doc", httpMethod = "POST",produces="application/json",notes = "导出用户确认信息表doc")
    public ResultBean  userRequireInfo() throws  IOException{
        Configuration configuration = new Configuration();
        configuration.setDefaultEncoding("utf-8");
        configuration.setClassForTemplateLoading(this.getClass(), "/templates/code");
        Template template = configuration.getTemplate("need.ftl");
        Map<String , Object> resultMap = new HashMap<>();
        List<UserInfo> userInfoList = new ArrayList<>();
        userInfoList.add(new UserInfo("2019","安全环保处质量安全科2608室","风险研判","9:30","10:30","风险研判","风险研判原型设计","参照甘肃分公司提交的分析研判表，各个二级单位维护自己的风险研判信息，需要一个简单的风险上报流程，各个二级单位可以看到所有的分析研判信息作为一个知识成果共享。","张三","李四"));
        resultMap.put("userInfoList",userInfoList);
        File outFile = new File("userRequireInfo.doc");
        Writer out = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(outFile),"UTF-8"));
        try {
            template.process(resultMap,out);
            out.flush();
            out.close();
            return null;
        } catch (TemplateException e) {
            e.printStackTrace();
        }
        return ResultBean.success();
    }

	<#list userInfoList as user>
			获取值：${user.name} 
        	...
    </#list>

 @PostMapping("user/exportPic")
    @ResponseBody
    @ApiOperation(value="导出带图片的Word", httpMethod = "POST",produces="application/json",notes = "导出带图片的Word")
    public ResultBean exportPic() throws IOException {
        Configuration configuration = new Configuration();
        configuration.setDefaultEncoding("utf-8");
        configuration.setClassForTemplateLoading(this.getClass(), "/templates/code");
        Template template = configuration.getTemplate("userPic.ftl");
        Map<String,Object> map = new HashMap<>();
        map.put("name","gaolei");
        map.put("date","2015-10-12");
        map.put("imgCode",imageToString());
        File outFile = new File("userWithPicture.doc");
        Writer out = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(outFile),"UTF-8"));
        try {
            template.process(map,out);
            out.flush();
            out.close();
            return null;
        } catch (TemplateException e) {
            e.printStackTrace();
        }
        return  ResultBean.success();
    }

    public static String imageToString() {
        String imgFile = "E:\\gitee\\excel-poi\\src\\main\\resources\\static\\img\\a.png";
        InputStream in = null;
        byte[] data = null;
        try {
            in = new FileInputStream(imgFile);
            data = new byte[in.available()];
            in.read(data);
            in.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
        String imageCodeBase64 =  Base64Utils.encodeToString(data);

        return imageCodeBase64;
    }