异常记录：使用Sharepreferences抛出NullPointerException空指针异常

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解决方法

在AndroidManifest中配置Application的名字

前因

在使用自己定义的Application中初始化Sharepreferences总是提示空指针异常

package com.xinzhi.zhouzhi.model.prefs;

import android.content.Context;
import android.content.SharedPreferences;
import com.xinzhi.zhouzhi.application.MyApplication;

import javax.inject.Inject;

public class PreferencesHelperImpl implements PreferencesHelper {
    private SharedPreferences sharedPreferences;
    private static final String SP_NAME="my_sp";

    @Inject
    public PreferencesHelperImpl() {
        sharedPreferences =  MyApplication.getInstance().getSharedPreferences(SP_NAME, Context.
                MODE_PRIVATE);
    }

    @Override
    public void setToken(String token) {
        sharedPreferences.edit().putString("token",token).commit();
    }

    @Override
    public String getToken() {
        return sharedPreferences.getString("token","");
    }

    @Override
    public void setUserId(String userId) {
        sharedPreferences.edit().putString("userId",userId).commit();
    }

    @Override
    public String getUserId() {
        return sharedPreferences.getString("userId","");
    }
}

后果

 Process: com.xinzhi.zhouzhi, PID: 1994
    java.lang.RuntimeException: Unable to start activity ComponentInfo{com.xinzhi.zhouzhi/com.xinzhi.zhouzhi.page.splash.SplashActivity}: java.lang.NullPointerException
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2193)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2243)
        at android.app.ActivityThread.access$800(ActivityThread.java:135)
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196)
        at android.os.Handler.dispatchMessage(Handler.java:102)
        at android.os.Looper.loop(Looper.java:136)
        at android.app.ActivityThread.main(ActivityThread.java:5019)
        at java.lang.reflect.Method.invokeNative(Native Method)
        at java.lang.reflect.Method.invoke(Method.java:515)
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
        at dalvik.system.NativeStart.main(Native Method)
     Caused by: java.lang.NullPointerException
        at android.content.ContextWrapper.getSharedPreferences(ContextWrapper.java:173)
        at com.xinzhi.zhouzhi.model.prefs.PreferencesHelperImpl.<init>(PreferencesHelperImpl.java:17)
        at com.xinzhi.zhouzhi.model.prefs.PreferencesHelperImpl_Factory.get(PreferencesHelperImpl_Factory.java:15)
        at com.xinzhi.zhouzhi.model.prefs.PreferencesHelperImpl_Factory.get(PreferencesHelperImpl_Factory.java:6)
        at com.xinzhi.zhouzhi.dagger.Module.AppModule_ProvideDataManagerModelFactory.get(AppModule_ProvideDataManagerModelFactory.java:40)
        at com.xinzhi.zhouzhi.dagger.Module.AppModule_ProvideDataManagerModelFactory.get(AppModule_ProvideDataManagerModelFactory.java:12)
        at dagger.internal.DoubleCheck.get(DoubleCheck.java:47)
        at com.xinzhi.zhouzhi.dagger.component.DaggerAppComponent.getDataManagerModel(DaggerAppComponent.java:126)
        at com.xinzhi.zhouzhi.dagger.component.DaggerActivityComponent.getSplashPresenter(DaggerActivityComponent.java:54)
        at com.xinzhi.zhouzhi.dagger.component.DaggerActivityComponent.injectSplashActivity(DaggerActivityComponent.java:106)
        at com.xinzhi.zhouzhi.dagger.component.DaggerActivityComponent.inject(DaggerActivityComponent.java:87)
        at com.xinzhi.zhouzhi.page.splash.SplashActivity.setInject(SplashActivity.java:23)
        at com.xinzhi.zhouzhi.base.MvpBaseActivity.onCreateView(MvpBaseActivity.java:32)
        at com.xinzhi.zhouzhi.base.BaseActivity.onCreate(BaseActivity.java:33)
        at android.app.Activity.performCreate(Activity.java:5231)
        at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1104)
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2157)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2243) 
        at android.app.ActivityThread.access$800(ActivityThread.java:135) 
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196) 
        at android.os.Handler.dispatchMessage(Handler.java:102) 
        at android.os.Looper.loop(Looper.java:136) 
        at android.app.ActivityThread.main(ActivityThread.java:5019) 
        at java.lang.reflect.Method.invokeNative(Native Method) 
        at java.lang.reflect.Method.invoke(Method.java:515) 
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779) 
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595) 
        at dalvik.system.NativeStart.main(Native Method)