java - 在后台发送电子邮件

Question

我尝试过一个可以通过后台发送电子邮件的Android应用程序。当我点击发送按钮时，电子邮件未发送并收到 error android.os.NetworkOnMianThreadException 。请帮我解决这个错误。下面给出了我的完整代码和logcat..

GMailSender.java

public class GMailSender extends javax.mail.Authenticator
{
private String mailhost = "smtp.gmail.com";
private String user;
private String password;
private Session session;

static {
    Security.addProvider(new com.provider.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.host", mailhost);
    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 {
    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);
}

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");
    }
}
}

MainActivity.java

public class MainActivity extends Activity {

/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    final Button send = (Button) this.findViewById(R.id.send);
    final EditText userid = (EditText) this.findViewById(R.id.userid);
    final EditText password = (EditText) this.findViewById(R.id.password);
    final EditText from = (EditText) this.findViewById(R.id.from);
    final EditText to = (EditText) this.findViewById(R.id.to);
    final EditText subject = (EditText) this.findViewById(R.id.subject);
    final EditText body = (EditText) this.findViewById(R.id.body);

    send.setOnClickListener(new View.OnClickListener() {
            public void onClick(View view) {
                    GMailSender sender = new GMailSender(userid.getText()
                                    .toString(), password.getText().toString());
                    try {
                            sender.sendMail(subject.getText().toString(), body
                                            .getText().toString(), from.getText().toString(),
                                            to.getText().toString());
                    } catch (Exception e) {
                            Log.e("SendMail", e.getMessage(), e);
                    }
            }
    });
}
}

JSSEProvider.java

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;
            }
        });
    }
 }

Logcat

01-10 20:46:30.868: E/SendMail(23815): null
01-10 20:46:30.868: E/SendMail(23815): android.os.NetworkOnMainThreadException
01-10 20:46:30.868: E/SendMail(23815):  at android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1099)
01-10 20:46:30.868: E/SendMail(23815):  at java.net.InetAddress.lookupHostByName(InetAddress.java:392)
01-10 20:46:30.868: E/SendMail(23815):  at java.net.InetAddress.getAllByNameImpl(InetAddress.java:243)
01-10 20:46:30.868: E/SendMail(23815):  at java.net.InetAddress.getByName(InetAddress.java:296)
01-10 20:46:30.868: E/SendMail(23815):  at javax.mail.URLName.getHostAddress(URLName.java:487)
01-10 20:46:30.868: E/SendMail(23815):  at javax.mail.URLName.hashCode(URLName.java:463)
01-10 20:46:30.868: E/SendMail(23815):  at java.util.Hashtable.get(Hashtable.java:263)
01-10 20:46:30.868: E/SendMail(23815):  at javax.mail.Session.getPasswordAuthentication(Session.java:823)
01-10 20:46:30.868: E/SendMail(23815):  at javax.mail.Service.connect(Service.java:271)
01-10 20:46:30.868: E/SendMail(23815):  at javax.mail.Service.connect(Service.java:169)
01-10 20:46:30.868: E/SendMail(23815):  at javax.mail.Service.connect(Service.java:118)
01-10 20:46:30.868: E/SendMail(23815):  at javax.mail.Transport.send0(Transport.java:188)
01-10 20:46:30.868: E/SendMail(23815):  at javax.mail.Transport.send(Transport.java:118)
01-10 20:46:30.868: E/SendMail(23815):  at com.example.emailtestapp.GMailSender.sendMail(GMailSender.java:70)
01-10 20:46:30.868: E/SendMail(23815):  at com.example.emailtestapp.MainActivity$1.onClick(MainActivity.java:32)
01-10 20:46:30.868: E/SendMail(23815):  at android.view.View.performClick(View.java:3534)
01-10 20:46:30.868: E/SendMail(23815):  at android.view.View$PerformClick.run(View.java:14172)
01-10 20:46:30.868: E/SendMail(23815):  at android.os.Handler.handleCallback(Handler.java:605)
01-10 20:46:30.868: E/SendMail(23815):  at android.os.Handler.dispatchMessage(Handler.java:92)
   01-10 20:46:30.868: E/SendMail(23815):   at android.os.Looper.loop(Looper.java:154)
   01-10 20:46:30.868: E/SendMail(23815):   at android.app.ActivityThread.main(ActivityThread.java:4624)
   01-10 20:46:30.868: E/SendMail(23815):   at java.lang.reflect.Method.invokeNative(Native Method)
   01-10 20:46:30.868: E/SendMail(23815):   at java.lang.reflect.Method.invoke(Method.java:511)
   01-10 20:46:30.868: E/SendMail(23815):   at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:965)
   01-10 20:46:30.868: E/SendMail(23815):   at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:732)
   01-10 20:46:30.868: E/SendMail(23815):   at dalvik.system.NativeStart.main(Native Method)

Answer 1

当应用程序尝试在其主线程上执行网络操作时，会引发此异常。在 AsyncTask Read more 中运行代码