Question

这个问题是关于如何在用Java编程时处理Netbeans中的库。

我正在开发一个Java项目，我们称之为ABC。其中一项活动是发送电子邮件。我的一些其他Java项目也发送电子邮件消息，因此我决定创建一个单独的Java项目来发送消息。这个项目叫做SendEmail。 SendEmail使用外部jar文件（javax.mail。*）。这些包括在SendEmail的项目属性 - ＆gt;中。图书馆 - ＆gt;添加JAR。测试SendEmail工作正常：当调用其方法sendMail（标题，内容）时，我是否收到发送的电子邮件。

项目ABC使用SendEmail，所以我已将其添加到ABC的库中：项目属性 - ＆gt;图书馆 - ＆gt;添加项目。 ABC编译并运行正常，直到它达到想要发送电子邮件的程度：它崩溃。

private void informUser(){
//create message title
//create message contents
SendEmail email = new SendEmail();
email.sendMail(title, contents); // <- it crashes here
}

错误信息表明它无法找到Authenticator类。此类位于外部jar文件中，该文件包含在SendEmail的库中。我只能通过将外部jar文件包含在ABC的库中来避免这种崩溃。这是我没想到的必要。 ABC不使用这些外部jar文件，只使用SendEmail。

我的问题：我做错了吗？我认为ABC没有使用这些外部jar，所以他们不需要在ABC的图书馆。

Answer 1

在你的代码中没有验证器部分。此代码只能使用gmail电子邮件，可以更改smtp服务器选项。我的代码：

import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.security.Security;
import java.util.Properties;

import javax.activation.DataHandler;
import javax.activation.DataSource;
import javax.mail.Message;
import javax.mail.PasswordAuthentication;
import javax.mail.Session;
import javax.mail.Transport;
import javax.mail.internet.InternetAddress;
import javax.mail.internet.MimeMessage;


public class GmailSender extends javax.mail.Authenticator {

    private String user;
    private String password;
    private Session session;

    static {
        Security.addProvider(new JSSEProvider());
    }

    public GmailSender(String user, String password) {
        this.user = user;
        this.password = password;

        Properties props = new Properties();
        props.setProperty("mail.transport.protocol", "smtp");
        props.setProperty("mail.smtp.host", "smtp.gmail.com");
        props.put("mail.smtp.starttls.enable", "true");
        props.put("mail.smtp.auth", "true");
        props.put("mail.smtp.port", "465");
        props.put("mail.smtp.socketFactory.port", "465");
        props.put("mail.smtp.socketFactory.class",
                "javax.net.ssl.SSLSocketFactory");
        props.put("mail.smtp.socketFactory.fallback", "false");
        props.setProperty("mail.smtp.quitwait", "false");

        session = Session.getDefaultInstance(props, this);
    }

    protected PasswordAuthentication getPasswordAuthentication() {
        return new PasswordAuthentication(user, password);
    }

    public synchronized void sendMail(String subject, String body, String sender, String recipients) throws Exception {
        try {
            MimeMessage message = new MimeMessage(session);
            DataHandler handler = new DataHandler(new ByteArrayDataSource(body.getBytes(), "text/plain"));
            message.setSender(new InternetAddress(sender));
            message.setSubject(subject);
            message.setDataHandler(handler);
            if (recipients.indexOf(',') > 0)
                message.setRecipients(Message.RecipientType.TO, InternetAddress.parse(recipients));
            else
                message.setRecipient(Message.RecipientType.TO, new InternetAddress(recipients));
            Transport.send(message);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    public class ByteArrayDataSource implements DataSource {
        private byte[] data;
        private String type;

        public ByteArrayDataSource(byte[] data, String type) {
            super();
            this.data = data;
            this.type = type;
        }

        public ByteArrayDataSource(byte[] data) {
            super();
            this.data = data;
        }

        public void setType(String type) {
            this.type = type;
        }

        public String getContentType() {
            if (type == null)
                return "application/octet-stream";
            else
                return type;
        }

        public InputStream getInputStream() throws IOException {
            return new ByteArrayInputStream(data);
        }

        public String getName() {
            return "ByteArrayDataSource";
        }

        public OutputStream getOutputStream() throws IOException {
            throw new IOException("Not Supported");
        }
    }


}

你需要这门课吗？

import java.security.AccessController;
import java.security.Provider;

public class JSSEProvider extends Provider {
    public JSSEProvider() {
        super("HarmonyJSSE", 1.0, "Harmony JSSE Provider");
        AccessController.doPrivileged(new java.security.PrivilegedAction<Void>() {
            public Void run() {
                put("SSLContext.TLS",
                        "org.apache.harmony.xnet.provider.jsse.SSLContextImpl");
                put("Alg.Alias.SSLContext.TLSv1", "TLS");
                put("KeyManagerFactory.X509",
                        "org.apache.harmony.xnet.provider.jsse.KeyManagerFactoryImpl");
                put("TrustManagerFactory.X509",
                        "org.apache.harmony.xnet.provider.jsse.TrustManagerFactoryImpl");
                return null;
            }
        });
    }
}

使用此代码：

class SendEmailTask extends AsyncTask<Void, Void, Void> {

        @Override
        protected void onPreExecute() {
            super.onPreExecute();
        }

        @Override
        protected Void doInBackground(Void... params) {
            try {
                GmailSender sender = new GmailSender("from email", "from email password");
                //subject, body, sender, to
                StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
                StrictMode.setThreadPolicy(policy);
                sender.sendMail("your title",
                        "your content",
                        "from email",
                        "to email");
            } catch (Exception e) {              
                e.printStackTrace();
            }
            return null;
        }

        @Override
        protected void onPostExecute(Void result) {
            super.onPostExecute(result);

        }
    }

并运行

SendEmailTask sendEmailTask = new SendEmailTask();
sendEmailTask.execute();

<强> UPD1：库： 1. javax.activation 2. javax.mail

如何在Netbeans（Java）中正确使用库？

1 个答案: