一些三星设备的InvocationTargetException: On Logout

Question

在我的登出点击，

public void logOut(View v){
   LoggedInUser loggedInUser = CommonUtilities.getObjectFromSharedPreferances(this,     Global.LOGGED_IN_HEALOW_USER, LoggedInUser.class);
   CommonUtilities.updateDeviceSessionToServer(this, loggedInUser.getId(), "logout");   
    ----Clearing SharedPreferance-----
}

我有一个类有一些静态实用程序方法。使用它们，我正在将会话更新到服务器&注销时清除共享首选项。CommonUtilities的实用方法getObjectFromSharedPreferances如下:

public static <T> T getObjectFromSharedPreferances(Context context, String key, Class<T> returnType) {
        Object obj = null;
        Gson gson = new Gson();
        SharedPreferences settings = PreferenceManager.getDefaultSharedPreferences(context);
        String jsonStr = settings.getString(key, null);
        if (jsonStr != null) {
            obj = gson.fromJson(jsonStr, returnType);
        }
        return returnType.cast(obj);
    }

另一个实用程序方法updateDeviceSessionToServer只是发送会话状态到服务器。

但是当执行updateDeviceSessionToServer方法时，我得到异常。下面就是发生异常的(Line No 63)行。

CommonUtilities.updateDeviceSessionToServer(this, loggedInUser.getId(), "logout");

同样，我没有得到所有设备的异常。这种情况正在某些设备上发生，比如Galaxy s2;星系展览。

完整stackstrace如下:

"java.lang.IllegalStateException: Could not execute method of the activity
    at android.view.View$1.onClick(View.java:2178)
    at android.view.View.performClick(View.java:2574)
    at android.view.View$PerformClick.run(View.java:9238)
    at android.os.Handler.handleCallback(Handler.java:587)
    at android.os.Handler.dispatchMessage(Handler.java:92)
    at android.os.Looper.loop(Looper.java:130)
    at android.app.ActivityThread.main(ActivityThread.java:3691)
    at java.lang.reflect.Method.invokeNative(Native Method)
    at java.lang.reflect.Method.invoke(Method.java:507)
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:907)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:665)
    at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.reflect.InvocationTargetException
    at java.lang.reflect.Method.invokeNative(Native Method)
    at java.lang.reflect.Method.invoke(Method.java:507)
    at android.view.View$1.onClick(View.java:2173)
    ... 11 more
Caused by: java.lang.NullPointerException
    at com.ecw.healow.settings.SettingsMainActivity.logOut(SettingsMainActivity.java:63)
    ... 14 more
java.lang.reflect.InvocationTargetException
    at java.lang.reflect.Method.invokeNative(Native Method)
    at java.lang.reflect.Method.invoke(Method.java:507)
    at android.view.View$1.onClick(View.java:2173)
    at android.view.View.performClick(View.java:2574)
    at android.view.View$PerformClick.run(View.java:9238)
    at android.os.Handler.handleCallback(Handler.java:587)
    at android.os.Handler.dispatchMessage(Handler.java:92)
    at android.os.Looper.loop(Looper.java:130)
    at android.app.ActivityThread.main(ActivityThread.java:3691)
    at java.lang.reflect.Method.invokeNative(Native Method)
    at java.lang.reflect.Method.invoke(Method.java:507)
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:907)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:665)
    at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.NullPointerException
    at com.ecw.healow.settings.SettingsMainActivity.logOut(SettingsMainActivity.java:63)
    ... 14 more
java.lang.NullPointerException
    at com.ecw.healow.settings.SettingsMainActivity.logOut(SettingsMainActivity.java:63)
    at java.lang.reflect.Method.invokeNative(Native Method)
    at java.lang.reflect.Method.invoke(Method.java:507)
    at android.view.View$1.onClick(View.java:2173)
    at android.view.View.performClick(View.java:2574)
    at android.view.View$PerformClick.run(View.java:9238)
    at android.os.Handler.handleCallback(Handler.java:587)
    at android.os.Handler.dispatchMessage(Handler.java:92)
    at android.os.Looper.loop(Looper.java:130)
    at android.app.ActivityThread.main(ActivityThread.java:3691)
    at java.lang.reflect.Method.invokeNative(Native Method)
    at java.lang.reflect.Method.invoke(Method.java:507)
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:907)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:665)
    at dalvik.system.NativeStart.main(Native Method)
"

我不明白这里发生了什么

Answer 1

我将从SettingsMainActivity.java文件中的第63行开始。根据堆栈跟踪，您在那里得到了一个NullPointerException:

Caused by: java.lang.NullPointerException
    at com.ecw.healow.settings.SettingsMainActivity.logOut(SettingsMainActivity.java:63)
    ...