commons-email，TLS加密後報錯

commons-email-1.4.jar
javax.mail-1.5.2.jar

public class mail {
    public static void main(String[] args)  {
        MultiPartEmail  mail = new MultiPartEmail ();
        mail.setHostName("192.168.10.30");
        mail.setAuthentication("test@hongtiantao.com", "fhAS");
        mail.setCharset("UTF-8");
        try {
            mail.setFrom("test@hongtiantao.com", "紅天桃客戶服務");
            mail.addTo("17991@qq.com","Chrome");
            mail.setSubject("待辦事務提醒");
            mail.setMsg("A" + "有一條新記錄" + "Z" + "等待審覈");
            mail.setStartTLSEnabled(true);
            mail.setSmtpPort(587);
            mail.send();
        } catch (EmailException e) {
            e.printStackTrace();
        }

    }

DEBUG SMTP: Found extension "PIPELINING", arg ""
DEBUG SMTP: Found extension "SIZE", arg "15728640"
DEBUG SMTP: Found extension "ETRN", arg ""
DEBUG SMTP: Found extension "STARTTLS", arg ""
DEBUG SMTP: Found extension "ENHANCEDSTATUSCODES", arg ""
DEBUG SMTP: Found extension "8BITMIME", arg ""
DEBUG SMTP: Found extension "DSN", arg ""
STARTTLS
220 2.0.0 Ready to start TLS
javax.mail.MessagingException: Could not convert socket to TLS;
  nested exception is:
    javax.net.ssl.SSLHandshakeException: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
    at com.sun.mail.smtp.SMTPTransport.startTLS(SMTPTransport.java:2155)
    at com.sun.mail.smtp.SMTPTransport.protocolConnect(SMTPTransport.java:752)
    at javax.mail.Service.connect(Service.java:366)
    at javax.mail.Service.connect(Service.java:246)
    at EmailTest.main(EmailTest.java:42)
Caused by: javax.net.ssl.SSLHandshakeException: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
    at sun.security.ssl.Alerts.getSSLException(Alerts.java:192)
    at sun.security.ssl.SSLSocketImpl.fatal(SSLSocketImpl.java:1884)
    at sun.security.ssl.Handshaker.fatalSE(Handshaker.java:276)
    at sun.security.ssl.Handshaker.fatalSE(Handshaker.java:270)
    at sun.security.ssl.ClientHandshaker.serverCertificate(ClientHandshaker.java:1439)
    at sun.security.ssl.ClientHandshaker.processMessage(ClientHandshaker.java:209)
    at sun.security.ssl.Handshaker.processLoop(Handshaker.java:878)
    at sun.security.ssl.Handshaker.process_record(Handshaker.java:814)
    at sun.security.ssl.SSLSocketImpl.readRecord(SSLSocketImpl.java:1016)
    at sun.security.ssl.SSLSocketImpl.performInitialHandshake(SSLSocketImpl.java:1312)
    at sun.security.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:1339)
    at sun.security.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:1323)
    at com.sun.mail.util.SocketFetcher.configureSSLSocket(SocketFetcher.java:626)
    at com.sun.mail.util.SocketFetcher.startTLS(SocketFetcher.java:553)
    at com.sun.mail.smtp.SMTPTransport.startTLS(SMTPTransport.java:2150)
    ... 4 more
Caused by: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
    at sun.security.validator.PKIXValidator.doBuild(PKIXValidator.java:385)
    at sun.security.validator.PKIXValidator.engineValidate(PKIXValidator.java:292)
    at sun.security.validator.Validator.validate(Validator.java:260)
    at sun.security.ssl.X509TrustManagerImpl.validate(X509TrustManagerImpl.java:326)
    at sun.security.ssl.X509TrustManagerImpl.checkTrusted(X509TrustManagerImpl.java:231)
    at sun.security.ssl.X509TrustManagerImpl.checkServerTrusted(X509TrustManagerImpl.java:126)
    at sun.security.ssl.ClientHandshaker.serverCertificate(ClientHandshaker.java:1421)
    ... 14 more
Caused by: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
    at sun.security.provider.certpath.SunCertPathBuilder.engineBuild(SunCertPathBuilder.java:196)
    at java.security.cert.CertPathBuilder.build(CertPathBuilder.java:268)
    at sun.security.validator.PKIXValidator.doBuild(PKIXValidator.java:380)
    ... 20 more

JDK1.7沒法運行，報錯爲PKIX：unable to find valid certification path to requested target，更換1.8後正常運行。

更換後報錯
java.lang.RuntimeException: java.io.IOException: invalid constant type: 15，需單獨指定javassist 包版本，升級爲3.20.0-GA問題解決。

推薦另外一種方法（須要在spring中的相關jar）

import org.springframework.mail.SimpleMailMessage;
import org.springframework.mail.javamail.JavaMailSenderImpl;

JavaMailSenderImpl mailSender = new JavaMailSenderImpl();
    /**
     * 初始化郵件發送數據
     *
     * @param host     服務器
     * @param username 發送人
     * @param passwd   發送人密碼
     */
    public void initData(String host, String username, String passwd)
    {
        //建立郵件發送服務器
        mailSender.setHost(host);
        mailSender.setPort(587);
        mailSender.setUsername(username);
        mailSender.setPassword(passwd);
        //加認證機制
        Properties javaMailProperties = new Properties();
        javaMailProperties.put("mail.smtp.auth", true);
        javaMailProperties.put("mail.smtp.starttls.enable", true);
        javaMailProperties.put("mail.smtp.timeout", 5000);
        javaMailProperties.put("mail.smtp.ssl.trust", "*");
        mailSender.setJavaMailProperties(javaMailProperties);
        System.out.println("初始化郵件發送信息完成");
    }

    /**
     * 發送普通文本
     *
     * @param email   對方郵箱地址
     * @param subject 主題
     * @param text    郵件內容
     */
    public void simpleMailSend(String email, String subject, String text)
    {
        //建立郵件內容
        SimpleMailMessage message = new SimpleMailMessage();
        message.setFrom(mailSender.getUsername());
        message.setTo(email);
        message.setSubject(subject);
        message.setText(text);
        //發送郵件
        mailSender.send(message);
        System.out.println("發送成功");
    }


    @Test
    public void testSpringEmail()
    {
        initData("192.168.10.30","test@hongti.com","fh");

        simpleMailSend("1964483239@qq.com","A","123");
    }