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Poi模板技术导入导出Excel
在我们的工作中, 也经常会用到Poi模板技术操作Excel文件数据, 而且不同的应用场景对Excel表格的单元格格式和合并操作都需要写大量的代码调试, 比较麻烦. 通过模板技术将自定义格式的Excel文件模板存放在服务器指定位置, 然后读取数据或者填充数据都使用该模板的样式, 不用自己去编写代码设置样式, 使用非常方便. 同样的, 本篇不会写入门案例, 只是记录自己工作或学习中封装的工具方法.
说明: 以下代码基于poi-3.17版本实现, poi-3.17及以上版本相比3.17以下版本样式设置的api改动比较大, 可能存在数据类型获取api过时或报错等, 请参考 Poi版本升级优化
1. 自定义注解
借鉴EasyPoi
和EasyExcel
的使用方式, 都通过注解开发方法来导出指定的字段或读取指定的属性数据. 下面我也自定义了一个简单的注解类.
com.poi.anno.ExcelAttr
package com.poi.anno;import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;/*** 自定义注解, 用于标识需要导出到Excel文件的属性字段*/
@Retention(RetentionPolicy.RUNTIME)
@Target(ElementType.FIELD)
public @interface ExcelAttr {int sort() default 0;
}
2. 定义数据模型
将导入或导出的数据与pojo实体类关联, 因为要写getter
, setter
方法, 我使用lombok
自动生成.
lombok
依赖
<dependency><groupId>org.projectlombok</groupId><artifactId>lombok</artifactId><version>1.18.20</version><optional>true</optional>
</dependency>
com.poi.entity.Employee
package com.poi.entity;import com.poi.anno.ExcelAttr;
import lombok.AllArgsConstructor;
import lombok.Builder;
import lombok.Data;
import lombok.NoArgsConstructor;/*** 类描述:数据模型, 员工信息* @Author wang_qz* @Date 2021/8/14 10:11* @Version 1.0*/
@Data
@NoArgsConstructor
@AllArgsConstructor
@Builder
public class Employee {@ExcelAttr(sort = 0)private int id;@ExcelAttr(sort = 1)private String name;@ExcelAttr(sort = 2)private String empno;@ExcelAttr(sort = 3)private int age;@ExcelAttr(sort = 4)private String sex;@ExcelAttr(sort = 5)private String job;@ExcelAttr(sort = 6)private int departid;
}
3. 大数据模板导入
3.1 导入Excel公共方法
com.poi.util.PoiTemplateUtil#importExcel
public List<T> importExcel(Map<String, Object> params, InputStream inputStream, Class<T> clazz) throws Exception {String fileType = (String) params.get("fileType");fileType = Objects.equals("xls", fileType) ? fileType : "xlsx";Workbook workbook = Objects.equals("xls", fileType) ? new HSSFWorkbook(inputStream) : new XSSFWorkbook(inputStream);Sheet sheet = workbook.getSheetAt(0);int lastRowNum = sheet.getLastRowNum();List<T> dataList = new ArrayList<>();for (int i = 1; i <= lastRowNum; i++) {Row row = sheet.getRow(i);short lastCellNum = row.getLastCellNum();// 获取单元格的值并存入objs中Object[] objs = new Object[lastCellNum];for (int j = 0; j < lastCellNum; j++) {Cell cell = row.getCell(j);Object value = getCellValue(cell);objs[j] = value;}T t = clazz.newInstance();// 反射设置属性值Field[] declaredFields = clazz.getDeclaredFields();for (int k = 0; k < declaredFields.length; k++) {Field field = declaredFields[k];field.setAccessible(true);// 获取被自定义注解ExcelAttr标识的字段ExcelAttr anno = field.getAnnotation(ExcelAttr.class);if (anno != null) {// 获取设置的字段排序int sort = anno.sort();if (sort == k) {String fieldType = field.getType().getName();final Object value = objs[k];if (Objects.equals("int", fieldType) || Objects.equals("Integer", fieldType)) {field.setInt(t, Integer.parseInt(value.toString()));} else if (Objects.equals("double", fieldType) ||Objects.equals("Double", fieldType)) {field.setDouble(t, Double.parseDouble(value.toString()));} else {field.set(t, value);}}}}dataList.add(t);}return dataList;
}
3.2 获取单元格数据类型
com.poi.util.PoiTemplateUtil#getCellValue
/*** 获取单元格的不同数据类型的值* @param cell* @return*/
public static Object getCellValue(Cell cell) {Object cellValue = ""; // 每个单元格的值if (cell != null) {// 数据类型判断, 获取不同类型的数据switch (cell.getCellTypeEnum()) {case NUMERIC: // 数字类型// 日期格式的数字if (HSSFDateUtil.isCellDateFormatted(cell)) {// 日期cellValue = cell.getDateCellValue();} else {// 不是日期格式的数字, 返回字符串格式cellValue = cell.getRichStringCellValue().toString();}break;case STRING: // 字符串cellValue = cell.getStringCellValue();break;case BOOLEAN: // 布尔cellValue = cell.getBooleanCellValue();break;case FORMULA: // 公式cellValue = String.valueOf(cell.getCellFormula());break;case BLANK: // 空cellValue = "";break;case ERROR: // 错误cellValue = "非法字符";break;default:cellValue = "未知类型";break;}}return cellValue;
}
4. 大数据模板导出
com.poi.util.PoiTemplateUtil#exportExcel
/*** 根据模板填充数据生成excel文件* @param params* @param outputStream* @throws Exception*/
public void exportExcel(@NonNull Map<String, Object> params, OutputStream outputStream) throws Exception {List<T> datas = (List<T>) params.get("datas");// "template/excel/template.xls"String template = (String) params.get("template"); int templateDataRowIndex = (int) params.get("templateDataRowIndex");String fileType = template.substring(template.lastIndexOf(".") + 1);fileType = Objects.equals("xls", fileType) ? fileType : "xlsx";InputStream templateStream = PoiTemplateUtil.class.getClassLoader().getResourceAsStream(template);Workbook workbook = Objects.equals("xls", fileType) ? new HSSFWorkbook(templateStream) : new XSSFWorkbook(templateStream);// 获取模板sheetSheet sheet = workbook.getSheetAt(0);// 获取模板数据行Row templateDataRow = sheet.getRow(templateDataRowIndex);// 将模板数据行样式用CellStyle数组存起来,后面填充数据用到该模板数据样式CellStyle[] cellStyles = new CellStyle[templateDataRow.getLastCellNum()];for (int i = 0; i < cellStyles.length; i++) {cellStyles[i] = templateDataRow.getCell(i).getCellStyle();}// 填充数据for (int i = 0; i < datas.size(); i++) {// 创建数据行-跟随模板Row row = sheet.createRow(i + templateDataRowIndex);T t = datas.get(i);Field[] declaredFields = t.getClass().getDeclaredFields();for (int j = 0; j < cellStyles.length; j++) {// 创建单元格Cell cell = row.createCell(j);// 设置单元格样式cell.setCellStyle(cellStyles[j]);for (Field field : declaredFields) {// 获取被@ExcelAttr注解标注且注解的sort=j的的属性field.setAccessible(true);ExcelAttr anno = field.getAnnotation(ExcelAttr.class);if (anno != null) {int sort = anno.sort();if (sort == j) {// 设置单元格的值cell.setCellValue(field.get(t).toString());}}}}}// 生成excel文件到指定位置workbook.write(outputStream);
}
5. 导入导出工具类全部代码
com.poi.util.PoiTemplateUtil
package com.poi.util;import com.poi.anno.ExcelAttr;
import com.poi.entity.Employee;
import lombok.NonNull;
import org.apache.poi.hssf.usermodel.HSSFDateUtil;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.ss.usermodel.*;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;import java.io.InputStream;
import java.io.OutputStream;
import java.lang.reflect.Field;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import java.util.Objects;/*** 类描述:模板导出excel工具类* @Author wang_qz* @Date 2021/8/14 10:30* @Version 1.0*/
public class PoiTemplateUtil<T> {/*** 根据模板填充数据生成excel文件* @param params* @param outputStream* @throws Exception*/public void exportExcel(@NonNull Map<String, Object> params, OutputStream outputStream) throws Exception {List<T> datas = (List<T>) params.get("datas");// "template/excel/template.xls"String template = (String) params.get("template"); int templateDataRowIndex = (int) params.get("templateDataRowIndex");String fileType = template.substring(template.lastIndexOf(".") + 1);fileType = Objects.equals("xls", fileType) ? fileType : "xlsx";InputStream templateStream = PoiTemplateUtil.class.getClassLoader().getResourceAsStream(template);Workbook workbook = Objects.equals("xls", fileType) ? new HSSFWorkbook(templateStream) : new XSSFWorkbook(templateStream);// 获取模板sheetSheet sheet = workbook.getSheetAt(0);// 获取模板数据行Row templateDataRow = sheet.getRow(templateDataRowIndex);// 将模板数据行样式用CellStyle数组存起来,后面填充数据用到该模板数据样式CellStyle[] cellStyles = new CellStyle[templateDataRow.getLastCellNum()];for (int i = 0; i < cellStyles.length; i++) {cellStyles[i] = templateDataRow.getCell(i).getCellStyle();}// 填充数据for (int i = 0; i < datas.size(); i++) {// 创建数据行-跟随模板Row row = sheet.createRow(i + templateDataRowIndex);T t = datas.get(i);Field[] declaredFields = t.getClass().getDeclaredFields();for (int j = 0; j < cellStyles.length; j++) {// 创建单元格Cell cell = row.createCell(j);// 设置单元格样式cell.setCellStyle(cellStyles[j]);for (Field field : declaredFields) {// 获取被@ExcelAttr注解标注且注解的sort=j的的属性field.setAccessible(true);ExcelAttr anno = field.getAnnotation(ExcelAttr.class);if (anno != null) {int sort = anno.sort();if (sort == j) {// 设置单元格的值cell.setCellValue(field.get(t).toString());}}}}}// 生成excel文件到指定位置workbook.write(outputStream);}/*** 大数据模板导入* @param params* @param inputStream* @param clazz* @return* @throws Exception*/public List<T> importExcel(Map<String, Object> params, InputStream inputStream,Class<T> clazz) throws Exception {String fileType = (String) params.get("fileType");fileType = Objects.equals("xls", fileType) ? fileType : "xlsx";Workbook workbook = Objects.equals("xls", fileType) ? new HSSFWorkbook(inputStream) : new XSSFWorkbook(inputStream);Sheet sheet = workbook.getSheetAt(0);int lastRowNum = sheet.getLastRowNum();List<T> dataList = new ArrayList<>();for (int i = 1; i <= lastRowNum; i++) {Row row = sheet.getRow(i);short lastCellNum = row.getLastCellNum();// 获取单元格的值并存入objs中Object[] objs = new Object[lastCellNum];for (int j = 0; j < lastCellNum; j++) {Cell cell = row.getCell(j);Object value = getCellValue(cell);objs[j] = value;}T t = clazz.newInstance();// 反射设置属性值Field[] declaredFields = clazz.getDeclaredFields();for (int k = 0; k < declaredFields.length; k++) {Field field = declaredFields[k];field.setAccessible(true);// 获取被自定义注解ExcelAttr标识的字段ExcelAttr anno = field.getAnnotation(ExcelAttr.class);if (anno != null) {// 获取设置的字段排序int sort = anno.sort();if (sort == k) {String fieldType = field.getType().getName();final Object value = objs[k];if (Objects.equals("int", fieldType) || Objects.equals("Integer", fieldType)) {field.setInt(t, Integer.parseInt(value.toString()));} else if (Objects.equals("double", fieldType) || Objects.equals("Double", fieldType)) {field.setDouble(t, Double.parseDouble(value.toString()));} else {field.set(t, value);}}}}dataList.add(t);}return dataList;}/*** 获取单元格的不同数据类型的值* @param cell* @return*/public static Object getCellValue(Cell cell) {Object cellValue = ""; // 每个单元格的值if (cell != null) {// 数据类型判断, 获取不同类型的数据switch (cell.getCellTypeEnum()) {case NUMERIC: // 数字类型// 日期格式的数字if (HSSFDateUtil.isCellDateFormatted(cell)) {// 日期cellValue = cell.getDateCellValue();} else {// 不是日期格式的数字, 返回字符串格式cellValue = cell.getRichStringCellValue().toString();}break;case STRING: // 字符串cellValue = cell.getStringCellValue();break;case BOOLEAN: // 布尔cellValue = cell.getBooleanCellValue();break;case FORMULA: // 公式cellValue = String.valueOf(cell.getCellFormula());break;case BLANK: // 空cellValue = "";break;case ERROR: // 错误cellValue = "非法字符";break;default:cellValue = "未知类型";break;}}return cellValue;}/*** 造测试数据* @return*/public static List<Employee> getDatas() {List<Employee> datas = new ArrayList<>();for (int i = 1; i <= 10; i++) {Employee employee = Employee.builder().id(Integer.valueOf(i)).departid(i * 100).empno("10000" + i).age(20 + i).sex(i % 2 == 0 ? "男" : "女").job(i % 2 == 0 ? "快递员" : "工程师").name("admin" + i).build();datas.add(employee);}return datas;}
}
6. 数据模板
数据模板就是自己设置好样式的excel文件, 放在项目类路径下, 如下所示:
template/excel/template.xls
7. 单元测试
7.1 测试大数据导入
com.test.poi.PoiTemplateTest#testImportExcel
@Test
public void testImportExcel() throws Exception {String filename = "D:\\study\\excel\\employees.xls";String fileType = filename.substring(filename.lastIndexOf(".") + 1);Map<String, Object> params = new HashMap<>();params.put("fileType", fileType);PoiTemplateUtil util = new PoiTemplateUtil();List<Employee> dataList = util.importExcel(params, new FileInputStream(filename), Employee.class);dataList.forEach(System.out::println);
}
通过控制台日志查看导入数据效果
7.2 测试大数据导出
com.test.poi.PoiTemplateTest#testExportExcel
@Test
public void testExportExcel() throws Exception {Map<String, Object> params = new HashMap<>();params.put("template", "template/excel/template.xls");params.put("templateDataRowIndex", 1); // 模板中第二行是带格式的数据行params.put("datas", getDatas());PoiTemplateUtil util = new PoiTemplateUtil();util.exportExcel(params, new FileOutputStream("D:\\study\\excel\\employees.xls"));
}
com.test.poi.PoiTemplateTest#getDatas
// 测试数据
public static List<Employee> getDatas() {List<Employee> datas = new ArrayList<>();for (int i = 1; i <= 10; i++) {Employee employee = Employee.builder().id(Integer.valueOf(i)).departid(i * 100).empno("10000" + i).age(20 + i).sex(i % 2 == 0 ? "男" : "女").job(i % 2 == 0 ? "快递员" : "工程师").name("admin" + i).build();datas.add(employee);}return datas;
}
导出数据效果
7.3 web端测试
7.3.1 编写controller
com.poi.controller.ExcelController
package com.poi.controller;import com.constant.CSISCONSTANT;
import com.exception.MyException;
import com.poi.entity.Employee;
import com.poi.service.ExcelReaderImpl;
import com.poi.util.PoiTemplateUtil;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.multipart.MultipartFile;import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.Part;
import java.io.*;
import java.net.URLEncoder;
import java.util.*;/*** 类描述:文件上传下载* @Author wang_qz* @Date 2021/8/14 21:07* @Version 1.0*/
@Controller
@RequestMapping("/excel")
public class ExcelController {@RequestMapping("/toExcelPage")public String todownloadPage() {return "excelPage";}@RequestMapping("/downloadExcel")public void downloadExcel(HttpServletResponse response) throws Exception {// 模板文件String template = "template/excel/template.xls";// 文件类型 xls xlsxString fileType = template.substring(template.lastIndexOf("."));// 设置响应头response.setContentType("application/vnd.ms-excel");response.setCharacterEncoding("utf-8");// 设置防止中文名乱码String filename = URLEncoder.encode("employees信息表", "utf-8");// 文件下载方式(附件下载还是在当前浏览器打开)response.setHeader("Content-disposition", "attachment;filename=" + filename +fileType);// 构建写入到excel文件的数据PoiTemplateUtil util = new PoiTemplateUtil();Map<String, Object> params = new HashMap<>();params.put("template", template);params.put("templateDataRowIndex", 1); // 模板中第二行是带格式的数据行params.put("datas", util.getDatas());util.exportExcel(params, response.getOutputStream());}@PostMapping("/uploadExcel")@ResponseBodypublic String uploadExcel(@RequestParam("file") Part part) throws Exception {// 获取上传的文件流InputStream inputStream = part.getInputStream();// 上传文件名称String filename = part.getSubmittedFileName();// 读取ExcelString fileType = filename.substring(filename.lastIndexOf(".") + 1);Map<String, Object> params = new HashMap<>();params.put("fileType", fileType);PoiTemplateUtil util = new PoiTemplateUtil();List<Employee> dataList = util.importExcel(params, inputStream,Employee.class);dataList.forEach(System.out::println);return "upload successful!";}@RequestMapping("/toExcelPage2")public String todownloadPage2() {return "excelPage2";}
}
7.3.1 编写jsp页面
webapp/WEB-INF/jsp/excelPage.jsp
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<html>
<head><title>测试excel文件下载</title>
</head>
<body>
<h3>点击下面链接, 进行excel文件下载</h3>
<a href="<c:url value='/excel/downloadExcel'/>">Excel文件下载</a>
<hr/>
<hr/>
<h3>点击下面按钮, 进行excel文件上传</h3>
<form action="<c:url value='/excel/uploadExcel'/>" method="post" enctype="multipart/form-data"><input type="file" name="file"/><br/><input type="submit" value="上传Excel"/>
</form>
</body>
</html>
启动tomcat
, 访问http://localhost:8080/excel/toExcelPage
, 进入测试页面:
7.3.4 测试效果
下载结果
上传效果
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