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我的AndroidManifest有关于我的应用程序类的问题。我已经在清单中设置了应用程序类,但是在运行期间,由于应用程序上下文为空,所以会抛出空指针异常。如何在AndroidManifest.xml中调试应用程序类问题?
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'android.content.Context com.example.prometheus.PrometheusApplication.getApplicationContext()' on a null object reference
at com.example.prometheus.tasks.NativeTasks.getPath(NativeTasks.java:119)
at com.example.prometheus.tasks.NativeTasks.chmod(NativeTasks.java:71)
at com.example.prometheus.tasks.FileTask.install(FileTask.java:55)
at com.example.prometheus.MainActivity.onCreate(MainActivity.java:29)
at android.app.Activity.performCreate(Activity.java:5990)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1106)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2278)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2387)
at android.app.ActivityThread.access$800(ActivityThread.java:151)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1303)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5254)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:903)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:698)
这就是应用程序类
package com.example.prometheus
import android.app.Application;
import android.content.SharedPreferences;
import android.content.pm.PackageInfo;
import android.content.pm.PackageManager;
import android.preference.PreferenceManager;
import android.util.Log;
public class PrometheusApplication extends Application {
private static PrometheusApplication mInstance;
public static PrometheusApplication getInstance(){
return mInstance;
}
public void onCreate() { super.onCreate(); }
public SharedPreferences getApplicationPreferences() {
return PreferenceManager.getDefaultSharedPreferences(getInstance());
}
}
我在清单中定义的应用程序类,如下所示
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.prometheus">
<application
android:allowBackup="true"
android:icon="@mipmap/ic_launcher"
android:label="@string/app_name"
android:name="PrometheusApplication"
android:theme="@style/AppTheme">
<activity
android:name=".MainActivity"
android:label="@string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>
此外,Android Studio不承认阶级(警告是class or interface expected
)。我已经将完整的软件包添加到了名称和类中,并添加了'。'在班级面前,没有什么帮助。
有没有人知道定义有什么问题,或者我该如何调试?
TIA
P.S:有对堆栈溢出有关这几个问题线程,多处理拼写问题或丢失的名字在清单(不适用于这种情况)的属性。