Spring Boot整合EasyExcel(完整版包含上传解析excel和下载模板)
<dependency> <groupId>com.alibaba</groupId> <artifactId>easyexcel</artifactId> <version>2.2.7</version> </dependency>2. 对读取excel内容(批量添加)
@PostMapping('plUpdate') public R plUpdate(@RequestParam('filename') MultipartFile file) throws IOException { //String Originalfilename = file.getOriginalFilename(); // String fileName = file.getName(); // System.out.println('orname='+Originalfilename+';'+'filename'+file.getName()); // 获取文件全名 String fileName = file.getOriginalFilename(); //设置文件路径 String templatePath = 'G:/excel/'; File dest0 = new File(templatePath); File dest = new File(dest0, fileName); //文件上传-覆盖 try { // 检测是否存在目录 if (!dest0.getParentFile().exists()) {dest0.getParentFile().mkdirs();//检测文件是否存在 } if (!dest.exists()) {dest.mkdirs(); } file.transferTo(dest); } catch (Exception e) { return R.error(); } String finameUrl = templatePath+fileName; ExcelReader excelReader = null; try { //TeacherExcel.class对应的是和模板一样的实体类, //eduTeacherService对应持久层的接口 excelReader = EasyExcel.read(finameUrl, TeacherExcel.class, new DemoDataListener(eduTeacherService)).build(); ReadSheet readSheet = EasyExcel.readSheet(0).build(); excelReader.read(readSheet); } finally { if (excelReader != null) {// 这里千万别忘记关闭,读的时候会创建临时文件,到时磁盘会崩的excelReader.finish(); } } return R.ok(); }
创建一个监听类:
package com.atguigu.excel;import com.alibaba.excel.context.AnalysisContext;import com.alibaba.excel.event.AnalysisEventListener;import com.atguigu.eduservice.entity.EduTeacher;import com.atguigu.eduservice.entity.vo.TeacherExcel;import com.atguigu.eduservice.service.EduTeacherService;import org.slf4j.Logger;import org.slf4j.LoggerFactory;import java.util.ArrayList;import java.util.List;// 有个很重要的点 DemoDataListener 不能被spring管理,要每次读取excel都要new,然后里面用到spring可以构造方法传进去public class DemoDataListener extends AnalysisEventListener<TeacherExcel> { private static final Logger LOGGER = LoggerFactory.getLogger(DemoDataListener.class); //这里写持久层的类 private EduTeacherService eduTeacherService; /** * 如果使用了spring,请使用这个构造方法。每次创建Listener的时候需要把spring管理的类传进来 * * @param eduTeacherService */ public DemoDataListener( EduTeacherService eduTeacherService) {//进行持久层的类 this.eduTeacherService = eduTeacherService; } /** * 每隔5条存储数据库,实际使用中可以3000条,然后清理list ,方便内存回收 */ private static final int BATCH_COUNT = 5; List<TeacherExcel> list = new ArrayList<TeacherExcel>(); /** * 假设这个是一个DAO,当然有业务逻辑这个也可以是一个service。当然如果不用存储这个对象没用。 */ //private DemoDAO demoDAO; public DemoDataListener() { // 这里是demo,所以随便new一个。实际使用如果到了spring,请使用下面的有参构造函数 //demoDAO = new DemoDAO(); } /** * 如果使用了spring,请使用这个构造方法。每次创建Listener的时候需要把spring管理的类传进来 * * @param demoDAO */ /* public DemoDataListener(DemoDAO demoDAO) { this.demoDAO = demoDAO; }*/ /** * 这个每一条数据解析都会来调用 * * @param data * one row value. Is is same as {@link AnalysisContext#readRowHolder()} * @param context */ @Override public void invoke(TeacherExcel data, AnalysisContext context) { LOGGER.info('解析到一条数据:{}',data.toString()); list.add(data); // 达到BATCH_COUNT了,需要去存储一次数据库,防止数据几万条数据在内存,容易OOM } /** * 所有数据解析完成了 都会来调用 * * @param context */ @Override public void doAfterAllAnalysed(AnalysisContext context) { // 这里也要保存数据,确保最后遗留的数据也存储到数据库 saveData(); LOGGER.info('所有数据解析完成!'); } /** * 加上存储数据库 */ private void saveData() { LOGGER.info('{}条数据,开始存储数据库!', list.size()); //因为我excel模板的实体和插入数据库实体的类不一样,所以需要进行转化 for (int i =0;i<list.size();i++ ){ EduTeacher teacher = new EduTeacher(); teacher.setLevel(list.get(i).getLevel()); teacher.setCareer(list.get(i).getCareer()); teacher.setName(list.get(i).getName()); teacher.setSort(list.get(i).getSort()); teacher.setIntro(list.get(i).getIntro()); boolean save = eduTeacherService.save(teacher); if (save){System.out.println('第'+i+'添加成功'); } } } }
例如我的excel模板是:
实体类:
字段上ExcelProperty的注解可以使用index声明字段在模板中的顺序,使用value声明模板各个字段的名称。例如:
@ExcelProperty(value = “讲师简介”,index = 1)private String intro;
模板的实体类要和excel字段一样对应,不然会出错
效果:
3. 模板下载:创建一个工具类:
package com.atguigu.eduservice.config;import com.alibaba.excel.EasyExcel;import com.alibaba.excel.support.ExcelTypeEnum;import com.alibaba.excel.write.metadata.style.WriteCellStyle;import com.alibaba.excel.write.style.HorizontalCellStyleStrategy;import org.apache.poi.ss.usermodel.HorizontalAlignment;import javax.servlet.http.HttpServletResponse;import java.io.OutputStream;import java.net.URLEncoder;import java.util.List;/** * @author linjiazeng * @version 1.0 * @date 2020/12/28 22:29 **/public class ExcelUtil { /** * 导出 * @param response * @param data * @param fileName * @param sheetName * @param clazz * @throws Exception */ public static void writeExcel(HttpServletResponse response, List<? extends Object> data, String fileName, String sheetName, Class clazz) throws Exception { //表头样式 WriteCellStyle headWriteCellStyle = new WriteCellStyle(); //设置表头居中对齐 headWriteCellStyle.setHorizontalAlignment(HorizontalAlignment.CENTER); //内容样式 WriteCellStyle contentWriteCellStyle = new WriteCellStyle(); //设置内容靠左对齐 contentWriteCellStyle.setHorizontalAlignment(HorizontalAlignment.LEFT); HorizontalCellStyleStrategy horizontalCellStyleStrategy = new HorizontalCellStyleStrategy(headWriteCellStyle, contentWriteCellStyle); EasyExcel.write(getOutputStream(fileName, response), clazz).excelType(ExcelTypeEnum.XLSX).sheet(sheetName).registerWriteHandler(horizontalCellStyleStrategy).doWrite(data); } private static OutputStream getOutputStream(String fileName, HttpServletResponse response) throws Exception { fileName = URLEncoder.encode(fileName, 'UTF-8'); response.setContentType('application/vnd.ms-excel'); response.setCharacterEncoding('utf8'); response.setHeader('Content-Disposition', 'attachment;filename=' + fileName + '.xlsx'); response.addHeader('Access-Control-Expose-Headers', 'Content-disposition'); return response.getOutputStream(); }}
调用工具类下载模板
/*下载模板*/ @GetMapping('/download/template') public void downloadTemplate(HttpServletResponse response){ String fileName = '导入讲师模板'; String sheetName='导入讲师模板'; List<TeacherExcel> teacherExcelList = new ArrayList<>(); TeacherExcel teacherExcel = new TeacherExcel(); teacherExcel.setName('ljz'); teacherExcel.setIntro('清华毕业,高材生'); teacherExcel.setCareer('资深讲师'); teacherExcel.setSort(1); teacherExcel.setLevel(1); teacherExcelList.add(teacherExcel); try { //TeacherExcel.class对应你的模板类 //teacherExcelList模板的例子 //也可以使用这种方式导出你查询出数据excel文件 ExcelUtil.writeExcel(response,teacherExcelList,fileName,sheetName,TeacherExcel.class); } catch (Exception e) { System.out.println(e.getCause()); } }
效果:
有问题可以互相交流,也可以去EasyExcel官网学习
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