私はここでAndroidFacebookチュートリアルを行っています：https ：//developers.facebook.com/docs/howtos/androidsdk/3.0/fetch-user-data/
このコードのチャンクでは：
private String buildUserInfoDisplay(GraphUser user) {
StringBuilder userInfo = new StringBuilder("");
Log.d("Graphuser:user",user.toString());
Log.d("StringBuilder:userInfo",userInfo.toString());
// Example: typed access (name)
// - no special permissions required
Log.d("Name: ",String.format("Name: %s\n\n", user.getName()));
userInfo.append(String.format("Name: %s\n\n", user.getName()));
// Example: typed access (birthday)
// - requires user_birthday permission
//userInfo.append(String.format("Birthday: %s\n\n", user.getBirthday()));
// Example: partially typed access, to location field,
// name key (location)
// - requires user_location permission
//userInfo.append(String.format("Location: %s\n\n", user.getLocation().getProperty("name")));
// Example: access via property name (locale)
// - no special permissions required
userInfo.append(String.format("Locale: %s\n\n", user.getProperty("locale")));
// Get a list of languages from an interface that
// extends the GraphUser interface and that returns
// a GraphObject list of MyGraphLanguage objects.
GraphObjectList<MyGraphLanguage> languages = (user.cast(MyGraphUser.class)).getLanguages();
Log.d("Languages",languages.toString());
if (languages.size() > 0) {
ArrayList<String> languageNames = new ArrayList<String> ();
// Iterate through the list of languages
for (MyGraphLanguage language : languages) {
// Add the language name to a list. Use the name
// getter method to get access to the name field.
languageNames.add(language.getName());
}
//userInfo.append(String.format("Languages: %s\n\n", languageNames.toString()));
}
return userInfo.toString();
}
userInfo.append （）関数は、nullポインター例外を引き起こします。誰かがこれに遭遇したことがありますか？チュートリアルと同じコードを使用していることを確認しました。
/*更新-Logcatを追加します*/
03-16 17:59:18.154: W/dalvikvm(1189): threadid=1: thread exiting with uncaught exception (group=0x40a13300)
03-16 17:59:18.204: E/AndroidRuntime(1189): FATAL EXCEPTION: main
03-16 17:59:18.204: E/AndroidRuntime(1189): java.lang.NullPointerException
03-16 17:59:18.204: E/AndroidRuntime(1189): at net.myname.myapp.MainFragment.buildUserInfoDisplay(MainFragment.java:84)
03-16 17:59:18.204: E/AndroidRuntime(1189): at net.myname.myapp.MainFragment.access$2(MainFragment.java:56)
03-16 17:59:18.204: E/AndroidRuntime(1189): at net.myname.myapp.MainFragment$2.onCompleted(MainFragment.java:125)
03-16 17:59:18.204: E/AndroidRuntime(1189): at com.facebook.Request$1.onCompleted(Request.java:264)
03-16 17:59:18.204: E/AndroidRuntime(1189): at com.facebook.Request$4.run(Request.java:1240)
03-16 17:59:18.204: E/AndroidRuntime(1189): at android.os.Handler.handleCallback(Handler.java:615)
03-16 17:59:18.204: E/AndroidRuntime(1189): at android.os.Handler.dispatchMessage(Handler.java:92)
03-16 17:59:18.204: E/AndroidRuntime(1189): at android.os.Looper.loop(Looper.java:137)
03-16 17:59:18.204: E/AndroidRuntime(1189): at android.app.ActivityThread.main(ActivityThread.java:4745)
03-16 17:59:18.204: E/AndroidRuntime(1189): at java.lang.reflect.Method.invokeNative(Native Method)
03-16 17:59:18.204: E/AndroidRuntime(1189): at java.lang.reflect.Method.invoke(Method.java:511)
03-16 17:59:18.204: E/AndroidRuntime(1189): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786)
03-16 17:59:18.204: E/AndroidRuntime(1189): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
03-16 17:59:18.204: E/AndroidRuntime(1189): at dalvik.system.NativeStart.main(Native Method)
03-16 17:59:18.354: D/dalvikvm(1189): GC_CONCURRENT freed 423K, 6% free 8428K/8903K, paused 107ms+76ms, total 316ms