一旦代码中的这一行执行
，我就会得到空指针异常accessToken =twitter.getOAuthAccessToken(LoginThread.requestToken, verifier);
Login.Thread和verifier参数看起来很好。
这是我的课程，我收到错误
public class UserClass extends Activity {
// Preference Constants
static String PREFERENCE_NAME = "twitter_oauth";
static final String PREF_KEY_OAUTH_TOKEN = "oauth_token";
static final String PREF_KEY_OAUTH_SECRET = "oauth_token_secret";
static final String URL_TWITTER_OAUTH_VERIFIER = "oauth_verifier";
static final String PREF_KEY_TWITTER_LOGIN = "isTwitterLogedIn";
static final String TWITTER_CALLBACK_URL = "oauth://t4jsample";
static final String URL_TWITTER_AUTH = "auth_url";
static final String URL_TWITTER_OAUTH_TOKEN = "oauth_token";
static Twitter twitter;
// Get the access token
AccessToken accessToken;
// Shared Preferences
public static SharedPreferences mSharedPreferences;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.user_page);
// Shared Preferences
mSharedPreferences = getApplicationContext().getSharedPreferences("MyPref", 0);
setLoginKeysClass obj = new setLoginKeysClass();
obj.execute();
}
public class setLoginKeysClass extends AsyncTask<Void, Void, AccessToken>
{
@Override
protected AccessToken doInBackground(Void... params) {
// TODO Auto-generated method stub
Uri uri = getIntent().getData();
if (uri != null && uri.toString().startsWith(TWITTER_CALLBACK_URL)) {
// oAuth verifier
String verifier = uri.getQueryParameter(URL_TWITTER_OAUTH_VERIFIER);
try {
accessToken =twitter.getOAuthAccessToken(LoginThread.requestToken, verifier); // LoginThread is a class
// Shared Preferences
Editor e = mSharedPreferences.edit();
// After getting access token, access token secret
// store them in application preferences
//e.putString(PREF_KEY_OAUTH_TOKEN, accessToken.getToken());
//e.putString(PREF_KEY_OAUTH_SECRET,accessToken.getTokenSecret());
// Store login status - true
e.putBoolean(PREF_KEY_TWITTER_LOGIN, true);
e.commit(); // save changes
return accessToken;
}
catch (Exception e) {
// TODO Auto-generated catch block
// e.printStackTrace();
return null;
}
}
return null;
}
}
}
这是 LogCat 。
03-13 10:04:44.623: D/AndroidRuntime(17352): Shutting down VM
03-13 10:04:44.623: W/dalvikvm(17352): threadid=1: thread exiting with uncaught exception (group=0x41a4a700)
03-13 10:04:44.638: E/AndroidRuntime(17352): FATAL EXCEPTION: main
03-13 10:04:44.638: E/AndroidRuntime(17352): java.lang.IllegalStateException: Could not execute method of the activity
03-13 10:04:44.638: E/AndroidRuntime(17352): at android.view.View$1.onClick(View.java:3838)
03-13 10:04:44.638: E/AndroidRuntime(17352): at android.view.View.performClick(View.java:4475)
03-13 10:04:44.638: E/AndroidRuntime(17352): at android.view.View$PerformClick.run(View.java:18784)
03-13 10:04:44.638: E/AndroidRuntime(17352): at android.os.Handler.handleCallback(Handler.java:730)
03-13 10:04:44.638: E/AndroidRuntime(17352): at android.os.Handler.dispatchMessage(Handler.java:92)
03-13 10:04:44.638: E/AndroidRuntime(17352): at android.os.Looper.loop(Looper.java:137)
03-13 10:04:44.638: E/AndroidRuntime(17352): at android.app.ActivityThread.main(ActivityThread.java:5414)
03-13 10:04:44.638: E/AndroidRuntime(17352): at java.lang.reflect.Method.invokeNative(Native Method)
03-13 10:04:44.638: E/AndroidRuntime(17352): at java.lang.reflect.Method.invoke(Method.java:525)
03-13 10:04:44.638: E/AndroidRuntime(17352): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1187)
03-13 10:04:44.638: E/AndroidRuntime(17352): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1003)
03-13 10:04:44.638: E/AndroidRuntime(17352): at dalvik.system.NativeStart.main(Native Method)
03-13 10:04:44.638: E/AndroidRuntime(17352): Caused by: java.lang.reflect.InvocationTargetException
03-13 10:04:44.638: E/AndroidRuntime(17352): at java.lang.reflect.Method.invokeNative(Native Method)
03-13 10:04:44.638: E/AndroidRuntime(17352): at java.lang.reflect.Method.invoke(Method.java:525)
03-13 10:04:44.638: E/AndroidRuntime(17352): at android.view.View$1.onClick(View.java:3833)
03-13 10:04:44.638: E/AndroidRuntime(17352): ... 11 more
03-13 10:04:44.638: E/AndroidRuntime(17352): Caused by: java.lang.IllegalStateException: Cannot execute task: the task has already been executed (a task can be executed only once)
03-13 10:04:44.638: E/AndroidRuntime(17352): at android.os.AsyncTask.executeOnExecutor(AsyncTask.java:578)
03-13 10:04:44.638: E/AndroidRuntime(17352): at android.os.AsyncTask.execute(AsyncTask.java:534)
03-13 10:04:44.638: E/AndroidRuntime(17352): at pack.locationinfo.MainActivity.TwitterLogin(MainActivity.java:75)
03-13 10:04:44.638: E/AndroidRuntime(17352): ... 14 more
答案 0 :(得分：0)
这是答案.. 我没有初始化twitter对象所以修改了我的代码
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.user_page);
ConfigurationBuilder builder = new ConfigurationBuilder();
builder.setOAuthConsumerKey(TWITTER_CONSUMER_KEY);
builder.setOAuthConsumerSecret(TWITTER_CONSUMER_SECRET);
Configuration configuration = builder.build();
TwitterFactory factory = new TwitterFactory(configuration);
twitter = factory.getInstance();
// Shared Preferences
mSharedPreferences = getApplicationContext().getSharedPreferences("MyPref", 0);
setLoginKeysClass obj = new setLoginKeysClass();
obj.execute();
.
.
.
}
现在一切正常