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 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：
/*
* Copyright 2006 Sun Microsystems, Inc. All Rights Reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* - Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* - Neither the name of Sun Microsystems nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
* IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
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 [: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：
1、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
2、cmd打开命令窗口，编译：javac InstallCert.java文件
立即学习“Java免费学习笔记（深入）”；
3、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
4、然后输入1退出。
5、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
6、若要上线功能，需要运维添加并导入证书。
7、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。
