Question

我是Android的新手。我在Android中集成了Facebook。该应用程序工作正常，但有一段时间后崩溃会出现以下错误。我的Facebook集成代码如下：

Login.class

public class Login extends Activity {
private static final String URL_PREFIX_FRIENDS = "https://graph.facebook.com/me/friends?access_token=";
private ImageButton buttonLoginLogout;
public static final String PREFS_PRIVATE = "PREFS_PRIVATE";
private Button b;

private Session.StatusCallback statusCallback = new SessionStatusCallback();
Databasehandler db=new Databasehandler(this);
HashMap<String, String>map=new HashMap<String, String>();
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.login);
    buttonLoginLogout = (ImageButton)findViewById(R.id.imageButton1);



    Settings.addLoggingBehavior(LoggingBehavior.INCLUDE_ACCESS_TOKENS);

    Session session = Session.getActiveSession();
    if (session == null) {
        if (savedInstanceState != null) {
            session = Session.restoreSession(this, null, statusCallback, savedInstanceState);
        }
        if (session == null) {
            session = new Session(this);
        }
        Session.setActiveSession(session);
        if (session.getState().equals(SessionState.CREATED_TOKEN_LOADED)) {
            session.openForRead(new Session.OpenRequest(this).setCallback(statusCallback));
        }
    }

    updateView();
}

@Override
public void onStart() {
    super.onStart();
    Session.getActiveSession().addCallback(statusCallback);
}

@Override
public void onStop() {
    super.onStop();
    Session.getActiveSession().removeCallback(statusCallback);
}



@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
    super.onActivityResult(requestCode, resultCode, data);
    Session.getActiveSession().onActivityResult(this, requestCode, resultCode, data);
}

@Override
protected void onSaveInstanceState(Bundle outState) {
    super.onSaveInstanceState(outState);
    Session session = Session.getActiveSession();
    Session.saveSession(session, outState);
}
@Override
protected void onDestroy() {

    super.onDestroy();

}
private void updateView() {
    Session session = Session.getActiveSession();
    if (session.isOpened()) {
        Request.executeMeRequestAsync(session,new Request.GraphUserCallback() {

            @Override
            public void onCompleted(GraphUser user, Response response) {
                // TODO Auto-generated method stub
                final String t1=user.getId();
                final String t2=user.getName();
                 // SharedPreferences myPrefs =getSharedPreferences("myprefs",MODE_WORLD_READABLE);
                int count=db.getme();
                if(count==0)
                {
                map.put("uid",t1.toString());
                map.put("name",t2.toString());
                db.insertnewuser(map);
                }
   }
        });

     Intent ik=new Intent(Login.this,MainActivity.class);

        ik.addFlags(Intent.FLAG_ACTIVITY_NO_ANIMATION);
        startActivity(ik);
         } else {

        buttonLoginLogout.setOnClickListener(new OnClickListener() {
            public void onClick(View view) { onClickLogin(); }
        });
    }
}

private void onClickLogin() {
    Session session = Session.getActiveSession();
    if (!session.isOpened() && !session.isClosed()) {
        session.openForRead(new Session.OpenRequest(this).setCallback(statusCallback));
    } else {
        Session.openActiveSession(this, true, statusCallback);
    }
}
 private class SessionStatusCallback implements Session.StatusCallback {
    @Override
    public void call(Session session, SessionState state, Exception exception) {
        updateView();
    }
}
}

错误日志：

 04-09 01:59:15.200: E/AndroidRuntime(5726): FATAL EXCEPTION: main
 04-09 01:59:15.200: E/AndroidRuntime(5726): Process: com.smacon.task, PID: 5726
 04-09 01:59:15.200: E/AndroidRuntime(5726): java.lang.NullPointerException
 04-09 01:59:15.200: E/AndroidRuntime(5726):    at com.smacon.task.Login$1.onCompleted(Login.java:355)
 04-09 01:59:15.200: E/AndroidRuntime(5726):    at com.facebook.Request$1.onCompleted(Request.java:269)
 04-09 01:59:15.200: E/AndroidRuntime(5726):    at com.facebook.Request$4.run(Request.java:1669)
 04-09 01:59:15.200: E/AndroidRuntime(5726):    at android.os.Handler.handleCallback(Handler.java:733)
 04-09 01:59:15.200: E/AndroidRuntime(5726):    at android.os.Handler.dispatchMessage(Handler.java:95)
 04-09 01:59:15.200: E/AndroidRuntime(5726):    at android.os.Looper.loop(Looper.java:136)
 04-09 01:59:15.200: E/AndroidRuntime(5726):    at android.app.ActivityThread.main(ActivityThread.java:5017)
 04-09 01:59:15.200: E/AndroidRuntime(5726):    at java.lang.reflect.Method.invokeNative(Native Method)
 04-09 01:59:15.200: E/AndroidRuntime(5726):    at java.lang.reflect.Method.invoke(Method.java:515)
 04-09 01:59:15.200: E/AndroidRuntime(5726):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
 04-09 01:59:15.200: E/AndroidRuntime(5726):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
 04-09 01:59:15.200: E/AndroidRuntime(5726):    at dalvik.system.NativeStart.main(Native Method)

Answer 1

user回调中onCompleted变量的值由于某种原因而为null。如果您要查看documentation，则会说：

user    The GraphObject representing the returned user, or null

因此，您应始终检查user是否为null。我不熟悉Facebook SDK，所以我不能说为什么它可以null，但我认为你可以从Response对象提供有关错误的有用信息。同样的方法。

为什么我的Facebook与Android应用程序集成崩溃？

1 个答案: