本篇内容主要讲解“怎么使用Java自带的mail API实现邮件发送功能”，感兴趣的朋友不妨来看看。本文介绍的方法操作简单快捷，实用性强。下面就让小编来带大家学习“怎么使用Java自带的mail API实现邮件发送功能”吧!
需求：
邮件发送 使用jdk源生API——java.mail实现发邮件功能
以下代码即可发送邮件，以qq邮箱为例
package com.example.demo.emailInfo;import javax.mail.Message;import javax.mail.MessagingException;import javax.mail.Session;import javax.mail.Transport;import javax.mail.internet.InternetAddress;import javax.mail.internet.MimeMessage;import java.io.UnsupportedEncodingException;import java.util.*;public class SendEmailInfo { public static void main(String[] args) throws MessagingException, UnsupportedEncodingException { String smtpServer = "smtp.qq.com"; String username = "939089358@qq.com"; //这里是你开通smtp协议的授权码，若是公司自定义服务器，可无需授权码，但需要配置证书，文章后面有详解 String password = "***********"; String receiver = "939089358@qq.com"; String receiver2 = "低调AI实验室@126.com"; //这里的配置可以自己抽取成工具 Properties properties = new Properties(); Map<String, Object> map = new HashMap<>(); //常用smtp使用配置，可以在其他文章中获取：这里针对使用qq发送邮件 map.put("mail.transport.protocol","smtp"); map.put("mail.smtp.host",smtpServer); map.put("mail.smtp.auth","true"); map.put("mail.smtp.port","465"); map.put("mail.smtp.socketFactory.class","javax.net.ssl.SSLSocketFactory"); map.put("mail.smtp.socketFactory.fallback",false); map.put("mail.smtp.socketFactory.port","465"); map.put("mail.smtp.starttls.enable","true"); properties.putAll(map); //创建会话对象，用户邮件和服务器的交互 Session session = Session.getDefaultInstance(properties);// session.setDebug(true); //查看发送邮件的log //创建一邮件 MimeMessage message = new MimeMessage(session); InternetAddress senderAddress = new InternetAddress(username,"设置自定义发件人名称","UTF-8"); message.setFrom(senderAddress); message.setRecipient(Message.RecipientType.TO,new InternetAddress(receiver,"收件人自定义名称","UTF-8")); message.setSubject("设置发送的主题：比如：邀请函","UTF-8"); message.setContent("内容：邀请你和我一起约会，在屋顶吹晚风，看星星，吃水果","text/html;charset=UTF-8"); message.setSentDate(new Date()); message.saveChanges(); //用session 获取传输对象,然后连接发件人 Transport transport = session.getTransport(); transport.connect(username,password); transport.sendMessage(message,message.getAllRecipients()); transport.close(); System.out.println("发送成功"); }}若要使用企业内部自搭服务器，则需要在jdk文件中配置一个授权证书，操作如下：
import java.io.*;import java.net.URL; import java.security.*;import java.security.cert.*; import javax.net.ssl.*; public class InstallCert { public static void main(String[] args) throws Exception { String host; int port; char[] passphrase; if ((args.length == 1) || (args.length == 2)) { String[] c = args[0].split(":"); host = c[0]; port = (c.length == 1) ? 443 : Integer.parseInt(c[1]); String p = (args.length == 1) ? "changeit" : args[1]; passphrase = p.toCharArray(); } else { System.out.println("Usage: java InstallCert <host>[:port] [passphrase]"); return; } File file = new File("jssecacerts"); if (file.isFile() == false) { char SEP = File.separatorChar; File dir = new File(System.getProperty("java.home") + SEP + "lib" + SEP + "security"); file = new File(dir, "jssecacerts"); if (file.isFile() == false) { file = new File(dir, "cacerts"); } } System.out.println("Loading KeyStore " + file + "..."); InputStream in = new FileInputStream(file); KeyStore ks = KeyStore.getInstance(KeyStore.getDefaultType()); ks.load(in, passphrase); in.close(); SSLContext context = SSLContext.getInstance("TLS"); TrustManagerFactory tmf = TrustManagerFactory.getInstance(TrustManagerFactory.getDefaultAlgorithm()); tmf.init(ks); X509TrustManager defaultTrustManager = (X509TrustManager)tmf.getTrustManagers()[0]; SavingTrustManager tm = new SavingTrustManager(defaultTrustManager); context.init(null, new TrustManager[] {tm}, null); SSLSocketFactory factory = context.getSocketFactory(); System.out.println("Opening connection to " + host + ":" + port + "..."); SSLSocket socket = (SSLSocket)factory.createSocket(host, port); socket.setSoTimeout(10000); try { System.out.println("Starting SSL handshake..."); socket.startHandshake(); socket.close(); System.out.println(); System.out.println("No errors, certificate is already trusted"); } catch (SSLException e) { System.out.println(); e.printStackTrace(System.out); } X509Certificate[] chain = tm.chain; if (chain == null) { System.out.println("Could not obtain server certificate chain"); return; } BufferedReader reader = new BufferedReader(new InputStreamReader(System.in)); System.out.println(); System.out.println("Server sent " + chain.length + " certificate(s):"); System.out.println(); MessageDigest sha1 = MessageDigest.getInstance("SHA1"); MessageDigest md5 = MessageDigest.getInstance("MD5"); for (int i = 0; i < chain.length; i++) { X509Certificate cert = chain[i]; System.out.println (" " + (i + 1) + " Subject " + cert.getSubjectDN()); System.out.println(" Issuer " + cert.getIssuerDN()); sha1.update(cert.getEncoded()); System.out.println(" sha1 " + toHexString(sha1.digest())); md5.update(cert.getEncoded()); System.out.println(" md5 " + toHexString(md5.digest())); System.out.println(); } System.out.println("Enter certificate to add to trusted keystore or 'q' to quit: [1]"); String line = reader.readLine().trim(); int k; try { k = (line.length() == 0) ? 0 : Integer.parseInt(line) - 1; } catch (NumberFormatException e) { System.out.println("KeyStore not changed"); return; } X509Certificate cert = chain[k]; String alias = host + "-" + (k + 1); ks.setCertificateEntry(alias, cert); OutputStream out = new FileOutputStream("jssecacerts"); ks.store(out, passphrase); out.close(); System.out.println(); System.out.println(cert); System.out.println(); System.out.println ("Added certificate to keystore 'jssecacerts' using alias '" + alias + "'"); } private static final char[] HEXDIGITS = "0123456789abcdef".toCharArray(); private static String toHexString(byte[] bytes) { StringBuilder sb = new StringBuilder(bytes.length * 3); for (int b : bytes) { b &= 0xff; sb.append(HEXDIGITS[b >> 4]); sb.append(HEXDIGITS[b & 15]); sb.append(' '); } return sb.toString(); } private static class SavingTrustManager implements X509TrustManager { private final X509TrustManager tm; private X509Certificate[] chain; SavingTrustManager(X509TrustManager tm) { this.tm = tm; } public X509Certificate[] getAcceptedIssuers() { throw new UnsupportedOperationException(); } public void checkClientTrusted(X509Certificate[] chain, String authType) throws CertificateException { throw new UnsupportedOperationException(); } public void checkServerTrusted(X509Certificate[] chain, String authType) throws CertificateException { this.chain = chain; tm.checkServerTrusted(chain, authType); } } }证书生成步骤：
完整复制以上Java代码，放到桌面上新建了一个跟类名相同的.java文件，并放入新建文件夹中
cmd打开命令窗口，编译：javac InstallCert.java文件
运行：java InstallCert Java请求出错的站点URL
即自行搭建的服务器域名：例如：smtp.AIRow.com
然后输入1退出。
检查桌面，会生成一个jssecacerts的文件，把该文件设置到你的JDK下的/jre/lib/security目录下即可
若要上线功能，需要运维添加并导入证书。
若不使用企业或个人自搭服务器发送邮件，则无需配置证书。
到此，相信大家对“怎么使用Java自带的mail API实现邮件发送功能”有了更深的了解，不妨来实际操作一番吧！这里是编程网网站，更多相关内容可以进入相关频道进行查询，关注我们，继续学习！
