目录
一：引入pom依赖
二：完整代码如下（真实可用）
本文章主要是讲述如何使用EasyExcel生成excel文件，并将文件写入到邮件附件中进行邮件发送。
一：引入pom依赖
<!-- 邮件 --><dependency><groupId>javax.mail</groupId><artifactId>mail</artifactId><version>1.4.7</version></dependency><!-- excel --><dependency><groupId>com.alibaba</groupId><artifactId>easyexcel</artifactId><version>2.2.7</version></dependency>
二：完整代码如下（真实可用）
有一些地方注意：
1.生成excel和发送邮件本身不属于很必要及时的动作，所以使用了线程池进行异步处理，有消息队列也可。
2.强烈建议类似的功能拆分成独立的模块服务进行部署，因为在后台生成excel写数据很耗费内存，容易导致oom。
3.邮件的附件是有大小限制的，需要注意。
@Datapublic class GenerateExcelSendEmailVo<T> {/*** 生成excel的数据*/private List<T> dataList;/*** excel的表头*/private List<String> tableHeadList;/*** 邮件收件人邮箱，支持多个收件人邮箱*/private List<String> acceptAddressList;/*** 邮件的标题*/private String emailTitle;/*** 邮件内容*/private String emailContent;}
/*** @Author xuhongchang* @Date /3/4 5:38 下午* @Describetion 项目中使用发送邮件*/@Component@Slf4jpublic class EmailUtil <T extends BaseRowModel>{@Autowiredprivate ExcelFactory excelFactory;@Autowiredprivate EmailService emailService;@Resourceprivate ThreadPoolTaskExecutor threadPool;/*** @Authorxuhongchang* @Date /3/5 10:47 上午* @Describetion 发送邮件的入口方法*/public void sendEmail(GenerateExcelSendEmailVo vo) {Long nanoTime = System.nanoTime();log.info("####开始发送邮件#### : {} -- {}", vo, nanoTime);threadPool.execute(() -> {generateExcelSendEmail(vo.getDataList(), vo.getTableHeadList(), vo.getAcceptAddressList(), vo.getEmailTitle(), vo.getEmailContent());log.info("####发送邮件结束#### : {}", nanoTime);});}/*** @Author xuhongchang* @Date /3/4 11:26 上午* @Describetion 生成excel并发送邮件*/public void generateExcelSendEmail(List<T> dataList, List<String> tableHeadList, List<String> acceptAddressList, String emailTitle, String content) {try {ByteArrayOutputStream out = new ByteArrayOutputStream();String fileName = "email_" + new Random().nextInt(10000) + System.currentTimeMillis() + ".xlsx";//生成excelexcelFactory.createExportExcel().createExcel(out, dataList, tableHeadList);// 发送邮件emailService.sendMsgFileDs(acceptAddressList, emailTitle, content, fileName, new ByteArrayInputStream(out.toByteArray()));} catch (Exception e) {log.error("发送邮件时报错：{}", e);}}}
@Componentpublic class ExcelFactory<T extends BaseRowModel> {public ExportExcelUtil<T> createExportExcel() {return new ExportExcelUtil<>();}}
@Component@Slf4jpublic class EmailService {private String USER_NAME = "";private String PASSWORD = "";public void sendMsgFileDs(List<String> acceptAddressList, String title, String text, String affixName, ByteArrayInputStream inputstream) {Session session = assembleSession();Message msg = new MimeMessage(session);try {msg.setFrom(new InternetAddress(USER_NAME));msg.setSubject(title);Address[] addressArr = acceptAddressList(acceptAddressList);msg.setRecipients(Message.RecipientType.TO, addressArr);MimeBodyPart contentPart = (MimeBodyPart) createContent(text, inputstream, affixName);//参数为正文内容和附件流MimeMultipart mime = new MimeMultipart("mixed");mime.addBodyPart(contentPart);msg.setContent(mime);Transport.send(msg);} catch (Exception e) {e.printStackTrace();}}public Address[] acceptAddressList(List<String> acceptAddressList) {// 创建邮件的接收者地址，并设置到邮件消息中Address[] tos = new InternetAddress[acceptAddressList.size()];try {for (int i = 0; i < acceptAddressList.size(); i++) {tos[i] = new InternetAddress(acceptAddressList.get(i));}} catch (AddressException e) {e.printStackTrace();}return tos;}public Session assembleSession() {String host = "host"; String mailStoreType = "smtp";String popPort = "587";final Properties props = new Properties();props.put("mail.smtp.auth", "true");props.put("mail.smtp.host", host);props.put("mail.store.protocol", mailStoreType);props.put("mail.smtp.port", popPort);//开启SSLprops.put("mail.smtp.starttls.enable", "true");props.put("mail.smtp.socketFactory.port", popPort);props.put("mail.smtp.socketFactory.fallback", "false");Session session = Session.getDefaultInstance(props, new MyAuthenricator(USER_NAME, PASSWORD));return session;}static Part createContent(String content, ByteArrayInputStream inputstream, String affixName) {MimeBodyPart contentPart = null;try {contentPart = new MimeBodyPart();MimeMultipart contentMultipart = new MimeMultipart("related");MimeBodyPart htmlPart = new MimeBodyPart();htmlPart.setContent(content, "text/html;charset=gbk");contentMultipart.addBodyPart(htmlPart);//附件部分MimeBodyPart excelBodyPart = new MimeBodyPart();DataSource dataSource = new ByteArrayDataSource(inputstream, "application/excel");DataHandler dataHandler = new DataHandler(dataSource);excelBodyPart.setDataHandler(dataHandler);excelBodyPart.setFileName(MimeUtility.encodeText(affixName));contentMultipart.addBodyPart(excelBodyPart);contentPart.setContent(contentMultipart);} catch (Exception e) {e.printStackTrace();}return contentPart;}//用户名密码验证，需要实现抽象类Authenticator的抽象方法PasswordAuthenticationstatic class MyAuthenricator extends Authenticator {String u = null;String p = null;public MyAuthenricator(String u, String p) {this.u = u;this.p = p;}@Overrideprotected PasswordAuthentication getPasswordAuthentication() {return new PasswordAuthentication(u, p);}}}
@Slf4j@Configurationpublic class ThreadPoolConfiguration {/*** 发送邮件的线程池* @return*/@Bean("threadPool")public ThreadPoolTaskExecutor taskExecutor() {ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor();// 设置核心线程数executor.setCorePoolSize(20);// 设置最大线程数executor.setMaxPoolSize(128);// 设置队列容量executor.setQueueCapacity(1000);// 设置线程活跃时间（秒）executor.setKeepAliveSeconds(60);// 设置默认线程名称executor.setThreadNamePrefix("发送邮件线程-");// 设置拒绝策略executor.setRejectedExecutionHandler(new ThreadPoolExecutor.CallerRunsPolicy());// 等待所有任务结束后再关闭线程池executor.setWaitForTasksToCompleteOnShutdown(true);return executor;}}
测试类代码如下：
// 测试对象@Datapublic class Student {private String userName;private String address;}
----------测试----------------------GenerateExcelSendEmailVo vo = new GenerateExcelSendEmailVo<>();// 1.构建导出数据内容List<Student> dataList = new ArrayList<>();Student student = new Student();student.setUserName("小许");student.setAddress("上海市 浦东新区");dataList.add(student);vo.setDataList(dataList);// 2.设置表头List<String> headList = new ArrayList<>();headList.add("姓名");headList.add("地址");vo.setTableHeadList(headList);// 3.设置email的titlevo.setEmailTitle("测试");//4.设置email的内容vo.setEmailContent("哈喽");// 5.设置收件人List<String> acceptAddressList = new ArrayList<>();acceptAddressList.add("xxx@");vo.setAcceptAddressList(acceptAddressList);// 6.发送邮件emailUtil.sendEmail(vo);
// 补流程缺少的类@Component@Slf4jpublic class ExportExcelUtil<T extends BaseRowModel> {public ExportExcelUtil() {}public void createExcel(ByteArrayOutputStream out, List<T> data, List<String> tableHeadList) throws IOException {try {List<List<String>> head = getExcelHead(tableHeadList);ExcelWriter writer = new ExcelWriter(null, out, ExcelTypeEnum.XLSX, true);Table table = new Table(0);table.setHead(head);Sheet sheet1 = new Sheet(1, 0);sheet1.setAutoWidth(true);sheet1.setSheetName("sheet1");writer.write(data, sheet1, table);writer.finish();out.flush();} finally {if (out != null) {out.close();}}}private List<List<String>> getExcelHead(List<String> tableHeadList){List<List<String>> head = new ArrayList<List<String>>();for (String s : tableHeadList) {List<String> column = new ArrayList<String>();column.add(s);head.add(column);}return head;}}
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