致命异常错误Android

Question

我正在尝试从我的 Android 设备通过 XMPPClient 连接到开放式服务器。我在Async-Task 上单独运行Network thread。

问题是

1- 我的代码不允许我连接到 openfire 服务器，但它可以轻松连接到 gmail 服务器。我的代码中是否缺少某些内容？

2-当我的系统连接到任何服务器（比如 gmail）时，它崩溃了，我在LogCat 中收到以下错误

错误

03-07 12:29:57.085: W/dalvikvm(26662): threadid=11: thread exiting with uncaught exception (group=0x40a95210)
03-07 12:29:57.115: E/AndroidRuntime(26662): FATAL EXCEPTION: AsyncTask #1
03-07 12:29:57.115: E/AndroidRuntime(26662): java.lang.RuntimeException: An error occured while executing doInBackground()
03-07 12:29:57.115: E/AndroidRuntime(26662):    at android.os.AsyncTask$3.done(AsyncTask.java:278)
03-07 12:29:57.115: E/AndroidRuntime(26662):    at java.util.concurrent.FutureTask$Sync.innerSetException(FutureTask.java:273)
03-07 12:29:57.115: E/AndroidRuntime(26662):    at java.util.concurrent.FutureTask.setException(FutureTask.java:124)
03-07 12:29:57.115: E/AndroidRuntime(26662):    at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:307)
03-07 12:29:57.115: E/AndroidRuntime(26662):    at java.util.concurrent.FutureTask.run(FutureTask.java:137)
03-07 12:29:57.115: E/AndroidRuntime(26662):    at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:208)
03-07 12:29:57.115: E/AndroidRuntime(26662):    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1076)
03-07 12:29:57.115: E/AndroidRuntime(26662):    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:569)
03-07 12:29:57.115: E/AndroidRuntime(26662):    at java.lang.Thread.run(Thread.java:856)
03-07 12:29:57.115: E/AndroidRuntime(26662): Caused by: java.lang.NullPointerException
03-07 12:29:57.115: E/AndroidRuntime(26662):    at com.example.test.NetworkOperation.doInBackground(NetworkOperation.java:42)
03-07 12:29:57.115: E/AndroidRuntime(26662):    at com.example.test.NetworkOperation.doInBackground(NetworkOperation.java:1)
03-07 12:29:57.115: E/AndroidRuntime(26662):    at android.os.AsyncTask$2.call(AsyncTask.java:264)
03-07 12:29:57.115: E/AndroidRuntime(26662):    at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:305)

这是在异步任务中运行的代码

import org.jivesoftware.smack.ConnectionConfiguration;
import org.jivesoftware.smack.XMPPConnection;
import org.jivesoftware.smack.XMPPException;
import org.jivesoftware.smack.packet.Presence;

import android.os.AsyncTask;
import android.util.Log;

public class NetworkOperation extends AsyncTask<String, Void, String> {

    private XMPPClient xmppClient;
    @Override
    protected String doInBackground(String... urls) {

        String host = "talk.google.com"; //getText(R.id.host);
        String port = "5222";  //getText(R.id.port);
        String service = "gmail.com"; //getText(R.id.service);
        String username = "hassaan.rabbani@gmail.com"; //getText(R.id.userid);
        String password = "**********"; //getText(R.id.password);

        // Create a connection
        ConnectionConfiguration connConfig =
                new ConnectionConfiguration(host, Integer.parseInt(port),service);
        XMPPConnection connection = new XMPPConnection(connConfig);

        try {
            connection.connect();
            Log.i("XMPPClient", "[SettingsDialog] Connected to " + connection.getHost());
        } catch (XMPPException ex) {
            Log.e("XMPPClient", "[SettingsDialog] Failed to connect to " + connection.getHost());
            xmppClient.setConnection(null);
        }
        try {
            connection.login(username, password);
            Log.i("XMPPClient", "Logged in as " + connection.getUser());

            // Set the status to available
            Presence presence = new Presence(Presence.Type.available);
            connection.sendPacket(presence);
            xmppClient.setConnection(connection);
        } catch (XMPPException ex) {
            Log.e("XMPPClient", "[SettingsDialog] Failed to log in as " + username);
            xmppClient.setConnection(null);
        }

      return null;
    }

    @Override
    protected void onPostExecute(String result) {

    }
  }

我错过了什么吗？吗？

Answer 1

看起来你从来没有为你的 xmppClient 变量分配任何东西，因此它是空的。

你没有在第一次尝试中就成功了。

Answer 2

试试下面的代码。

@Override
protected String doInBackground(String... urls) {

    String host = "talk.google.com"; //getText(R.id.host);
    String port = "5222";  //getText(R.id.port);
    String service = "gmail.com"; //getText(R.id.service);
    String username = "hassaan.rabbani@gmail.com"; //getText(R.id.userid);
    String password = "**********"; //getText(R.id.password);

    // Create a connection
    ConnectionConfiguration connConfig =
            new ConnectionConfiguration(host, Integer.parseInt(port),service);
    XMPPConnection connection = new XMPPConnection(connConfig);
    if(xmppClient != null){
    try {
        connection.connect();
        Log.i("XMPPClient", "[SettingsDialog] Connected to " + connection.getHost());
        connection.login(username, password);
        Log.i("XMPPClient", "Logged in as " + connection.getUser());

        // Set the status to available
        Presence presence = new Presence(Presence.Type.available);
        connection.sendPacket(presence);
        xmppClient.setConnection(connection);
    } catch (XMPPException ex) {
        Log.e("XMPPClient", "[SettingsDialog] Failed to connect to " + connection.getHost());
        xmppClient.setConnection(null);
    }
    }else{
        Log.d("Connection", "check your xmppClient");
    }

  return null;
}