Android Facebook 登录 NullPointerException
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Facebook login NullPointerException
提问by Ojonugwa Jude Ochalifu
Am trying to implement the Facebook login for Android using the Facebook SDK (3.17.1) but i am having some issues i haven't had in the past. First of all, the login button doesn't render completely. This is what i get
我正在尝试使用 Facebook SDK (3.17.1) 为 Android 实现 Facebook 登录，但我遇到了一些我过去没有遇到过的问题。首先，登录按钮没有完全呈现。这就是我得到的
instead of this:
而不是这个：
(notice the missing Facebook logo). When I run the application, in the split second before it crashes it displays it just the way it should (with the Facebook logo).
（请注意缺少的 Facebook 徽标）。当我运行该应用程序时，在它崩溃之前的一瞬间，它以它应有的方式显示它（带有 Facebook 徽标）。
When the application crashes, i get this error message
当应用程序崩溃时，我收到此错误消息
"Unfortunately, FacebookLoginTest as stopped"
"Unfortunately, FacebookLoginTest as stopped"
and this in Logcat:
这在 Logcat 中：
08-12 22:19:08.751: E/AndroidRuntime(7731): FATAL EXCEPTION: AsyncTask #1
08-12 22:19:08.751: E/AndroidRuntime(7731): Process: com.example.facebooklogintest, PID: 7731
08-12 22:19:08.751: E/AndroidRuntime(7731): java.lang.RuntimeException: An error occured while executing doInBackground()
08-12 22:19:08.751: E/AndroidRuntime(7731): at android.os.AsyncTask.done(AsyncTask.java:300)
08-12 22:19:08.751: E/AndroidRuntime(7731): at java.util.concurrent.FutureTask.finishCompletion(FutureTask.java:355)
08-12 22:19:08.751: E/AndroidRuntime(7731): at java.util.concurrent.FutureTask.setException(FutureTask.java:222)
08-12 22:19:08.751: E/AndroidRuntime(7731): at java.util.concurrent.FutureTask.run(FutureTask.java:242)
08-12 22:19:08.751: E/AndroidRuntime(7731): at android.os.AsyncTask$SerialExecutor.run(AsyncTask.java:231)
08-12 22:19:08.751: E/AndroidRuntime(7731): at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112)
08-12 22:19:08.751: E/AndroidRuntime(7731): at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587)
08-12 22:19:08.751: E/AndroidRuntime(7731): at java.lang.Thread.run(Thread.java:864)
08-12 22:19:08.751: E/AndroidRuntime(7731): Caused by: java.lang.NullPointerException
08-12 22:19:08.751: E/AndroidRuntime(7731): at java.util.concurrent.ConcurrentHashMap.containsKey(ConcurrentHashMap.java:911)
08-12 22:19:08.751: E/AndroidRuntime(7731): at com.facebook.internal.Utility.queryAppSettings(Utility.java:377)
08-12 22:19:08.751: E/AndroidRuntime(7731): at com.facebook.widget.LoginButton.doInBackground(LoginButton.java:677)
08-12 22:19:08.751: E/AndroidRuntime(7731): at com.facebook.widget.LoginButton.doInBackground(LoginButton.java:1)
08-12 22:19:08.751: E/AndroidRuntime(7731): at android.os.AsyncTask.call(AsyncTask.java:288)
08-12 22:19:08.751: E/AndroidRuntime(7731): at java.util.concurrent.FutureTask.run(FutureTask.java:237)
08-12 22:19:08.751: E/AndroidRuntime(7731): ... 4 more
08-12 22:19:10.753: D/Process(7731): killProcess, pid=7731
08-12 22:19:10.753: D/Process(7731): com.android.internal.os.RuntimeInit$UncaughtHandler.uncaughtException:131 java.lang.ThreadGroup.uncaughtException:693 java.lang.ThreadGroup.uncaughtException:690
I followed the instructions for adding Facebook login to Android apps:
我按照将 Facebook 登录添加到 Android 应用程序的说明进行操作：
- Imported Facebook sdk
- Added Facebook project as libray
- Added Facebook project to list of references for my project
- Cleaned and even restarted the project.
- 导入的 Facebook sdk
- 将 Facebook 项目添加为 libray
- 将 Facebook 项目添加到我的项目的参考列表中
- 清理甚至重新启动项目。
Besides these, I haven't changed anything in my Activity and manifest. I have tried this in three different eclipse versions, all with the same error, but then i delete the Facebook login button code in the .xml file, the app lauches just fine. Not sure what else am supposed to do. Here are the MainActivity and Layout.xml codes:
除此之外，我的 Activity 和 manifest 中没有任何更改。我已经在三个不同的 eclipse 版本中尝试过这个，都出现了相同的错误，但随后我删除了 .xml 文件中的 Facebook 登录按钮代码，应用程序运行得很好。不知道还应该做什么。以下是 MainActivity 和 Layout.xml 代码：
MainActivity.java
主活动.java
package com.example.facebooklogintest;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
public class MainActivity extends ActionBarActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
}
activity_main.xml
活动_main.xml
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context="com.example.facebooklogintest.MainActivity" >
<com.facebook.widget.LoginButton
android:id="@+id/authButton"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_alignParentRight="true"
android:layout_gravity="center_horizontal"
android:layout_marginTop="30dp" />
</RelativeLayout>
回答by apmartin1991
You need to change or add this in your manifest file
您需要在清单文件中更改或添加它
<activity
android:name="com.example.LoginActivity"
android:label="@string/app_name"
android:parentActivityName="com.example.MainActivity" >
</activity>
<activity android:name="com.facebook.LoginActivity"
android:theme="@android:style/Theme.Translucent.NoTitleBar"
android:label="@string/app_name" />
<meta-data android:name="com.facebook.sdk.ApplicationId" android:value="@string/app_id"/>
I cannot take credit for this, all credit must go to the guy who posted the answer hereI am purely adding the code for ease for you and because I got told to by someone who previously deleted the answer.
我不能因此而受到赞扬，所有功劳都必须归功于在此处发布答案的人，我纯粹是为了方便您而添加代码，因为之前删除了答案的人告诉了我。
回答by Ashutoshg
10-10 11:27:47.932: E/AndroidRuntime(25915): FATAL EXCEPTION: AsyncTask #5
10-10 11:27:47.932: E/AndroidRuntime(25915): Process: com.example.version_2, PID: 25915
10-10 11:27:47.932: E/AndroidRuntime(25915): java.lang.NullPointerException: Attempt to invoke virtual method 'int java.lang.Object.hashCode()' on a null object reference
10-10 11:27:47.932: E/AndroidRuntime(25915): at java.util.concurrent.ConcurrentHashMap.get(ConcurrentHashMap.java:746)
10-10 11:27:47.932: E/AndroidRuntime(25915): at java.util.concurrent.ConcurrentHashMap.containsKey(ConcurrentHashMap.java:774)
10-10 11:27:47.932: E/AndroidRuntime(25915): at com.facebook.internal.Utility.queryAppSettings(Utility.java:822)
10-10 11:27:47.932: E/AndroidRuntime(25915): at com.facebook.login.widget.LoginButton.run(LoginButton.java:489)
If you face above error in FB integration then the below solution will work. Just add Application ID in Meta-data tag in menifest file. It will work fine
如果您在 FB 集成中遇到上述错误，则以下解决方案将起作用。只需在menifest 文件的元数据标签中添加应用程序ID。它会正常工作
<meta-data android:name="com.facebook.sdk.ApplicationId" android:value="@string/app_id"/>
