使用ssl发送Java电子邮件

Question

我正在尝试使用带有java的SSL发送电子邮件。但是出现了关于它的错误。我使用keystore将SSL证书添加到java中的cacert。但问题仍然存在。 我使用keytool导入命令添加了SSL证书，添加证书后我查看了列表。他们还出现了证书

我的代码：

   import javax.mail.*;
   import javax.mail.internet.InternetAddress;
   import javax.mail.internet.MimeMessage;
   import java.util.Properties;

class Mailer{
    public static void send( final String from, final String password,String to,String sub,String msg){
        //Get properties object
        Properties props = new Properties();
        props.put("mail.smtp.host", "the host im using");
        props.put("mail.smtp.socketFactory.port", "465");
        props.put("mail.smtp.socketFactory.class",
                "javax.net.ssl.SSLSocketFactory");
        props.put("mail.smtp.auth", "true");
        props.put("mail.smtp.port", "465");
        props.put("mail.smtp.starttls.enable","true");
        props.put("mail.smtp.socketFactory.fallback", "false");

        Session session = Session.getDefaultInstance(props,
                new javax.mail.Authenticator() {
                    protected PasswordAuthentication getPasswordAuthentication() {
                        return new PasswordAuthentication(from,password);
                    }
                });

        try {
            MimeMessage message = new MimeMessage(session);
            message.addRecipient(Message.RecipientType.TO,new InternetAddress(to));
            message.setSubject(sub);
            message.setText(msg);
            Transport.send(message);
            System.out.println("message sent successfully");
        } catch (MessagingException e)
        {throw new RuntimeException(e);}

    }
}

public class SendEmail {

    public static void main(String[] args) {

        Mailer m =new Mailer();
        m.send("username", "password", "abc@gmail.com", "hello", "Second Sending ?");

    }
}


my pom.xml file:

  <?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>email</groupId>
    <artifactId>email-first</artifactId>
    <version>1.0-SNAPSHOT</version>

    <dependencies>
        <!-- https://mvnrepository.com/artifact/javax.mail/mail -->
        <dependency>
            <groupId>javax.mail</groupId>
            <artifactId>mail</artifactId>
            <version>1.4</version>
        </dependency>

        <!-- https://mvnrepository.com/artifact/javax.activation/activation -->
        <dependency>
            <groupId>javax.activation</groupId>
            <artifactId>activation</artifactId>
            <version>1.1.1</version>
        </dependency>
     </dependencies>

</project>

我得到的错误：

Exception in thread "main" java.lang.RuntimeException: javax.mail.MessagingException: Exception reading response;
  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 Mailer.send(SendEmail.java:43)
    at SendEmail.main(SendEmail.java:54)
Caused by: javax.mail.MessagingException: Exception reading response;
  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.readServerResponse(SMTPTransport.java:1462)
    at com.sun.mail.smtp.SMTPTransport.openServer(SMTPTransport.java:1260)
    at com.sun.mail.smtp.SMTPTransport.protocolConnect(SMTPTransport.java:370)
    at javax.mail.Service.connect(Service.java:297)
    at javax.mail.Service.connect(Service.java:156)
    at javax.mail.Service.connect(Service.java:105)
    at javax.mail.Transport.send0(Transport.java:168)
    at javax.mail.Transport.send(Transport.java:98)
    at Mailer.send(SendEmail.java:40)
    ... 1 more
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 com.sun.net.ssl.internal.ssl.Alerts.getSSLException(Alerts.java:174)
    at com.sun.net.ssl.internal.ssl.SSLSocketImpl.fatal(SSLSocketImpl.java:1747)
    at com.sun.net.ssl.internal.ssl.Handshaker.fatalSE(Handshaker.java:241)
    at com.sun.net.ssl.internal.ssl.Handshaker.fatalSE(Handshaker.java:235)
    at com.sun.net.ssl.internal.ssl.ClientHandshaker.serverCertificate(ClientHandshaker.java:1209)
    at com.sun.net.ssl.internal.ssl.ClientHandshaker.processMessage(ClientHandshaker.java:135)
    at com.sun.net.ssl.internal.ssl.Handshaker.processLoop(Handshaker.java:593)
    at com.sun.net.ssl.internal.ssl.Handshaker.process_record(Handshaker.java:529)
    at com.sun.net.ssl.internal.ssl.SSLSocketImpl.readRecord(SSLSocketImpl.java:943)
    at com.sun.net.ssl.internal.ssl.SSLSocketImpl.performInitialHandshake(SSLSocketImpl.java:1188)
    at com.sun.net.ssl.internal.ssl.SSLSocketImpl.readDataRecord(SSLSocketImpl.java:818)
    at com.sun.net.ssl.internal.ssl.AppInputStream.read(AppInputStream.java:75)
    at com.sun.mail.util.TraceInputStream.read(TraceInputStream.java:97)
    at java.io.BufferedInputStream.fill(BufferedInputStream.java:218)
    at java.io.BufferedInputStream.read(BufferedInputStream.java:237)
    at com.sun.mail.util.LineInputStream.readLine(LineInputStream.java:75)
    at com.sun.mail.smtp.SMTPTransport.readServerResponse(SMTPTransport.java:1440)
    ... 9 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:323)
    at sun.security.validator.PKIXValidator.engineValidate(PKIXValidator.java:217)
    at sun.security.validator.Validator.validate(Validator.java:218)
    at com.sun.net.ssl.internal.ssl.X509TrustManagerImpl.validate(X509TrustManagerImpl.java:126)
    at com.sun.net.ssl.internal.ssl.X509TrustManagerImpl.checkServerTrusted(X509TrustManagerImpl.java:209)
    at com.sun.net.ssl.internal.ssl.X509TrustManagerImpl.checkServerTrusted(X509TrustManagerImpl.java:249)
    at com.sun.net.ssl.internal.ssl.ClientHandshaker.serverCertificate(ClientHandshaker.java:1188)
    ... 21 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:174)
    at java.security.cert.CertPathBuilder.build(CertPathBuilder.java:238)
    at sun.security.validator.PKIXValidator.doBuild(PKIXValidator.java:318)
    ... 27 more

Process finished with exit code 1

I would be much grateful if anyone could give a solution for this.