Question

我想发布链接，如果用户登录facebook，如果没有让用户登录然后发布链接，但它在publishlink（）方法中的jsonobject graphresponse显示NullPointerException。

以下是我的代码..

public static final List<String> PERMISSIONS = Arrays.asList("publish_actions");
public static final String PENDING_PUBLISH_KEY = "pendingPublishReauthorization";
public boolean pendingPublishReauthorization = false;
private Session.StatusCallback statusCallback = new SessionStatusCallback();

public void ShareOnFacebook(String sharingpath)
{
    Session currentSession = Session.getActiveSession();
    if (currentSession == null || currentSession.getState().isClosed()) {
        Session session = new Session.Builder(getBaseContext()).build();
        Session.setActiveSession(session);
        currentSession = session;
    }

    else if (!currentSession.isOpened()) {
        // Ask for username and password
        OpenRequest op = new Session.OpenRequest(this);

        op.setLoginBehavior(SessionLoginBehavior.SUPPRESS_SSO);
        op.setCallback(statusCallback);

        List<String> permissions = new ArrayList<String>();
        permissions.add("publish_stream");
        op.setPermissions(permissions);

        Session session = new Session(this);
        Session.setActiveSession(session);
        Log.d("session", "opening sesion for publish action!!");
        session.openForPublish(op);
    }
    }

private class SessionStatusCallback implements Session.StatusCallback
{
    @Override
    public void call(final Session session, SessionState state, Exception exception)
    {
        //we have callback here

        if (session.isOpened())
        {
            Log.d("session", "session is already opened ,we are in the callback section...going to publish link!!");
            PublishLink();
    }
} 
}

public void PublishLink()
 {

SharedPreferences prefs = getSharedPreferences("shared",MODE_PRIVATE); 
String path = prefs.getString("path", "");

Session session = Session.getActiveSession();

        // Check for publish permissions   

        List<String> permissions = session.getPermissions();
        if (!isSubsetOf(PERMISSIONS, permissions)) {
            pendingPublishReauthorization = true;
            Session.NewPermissionsRequest newPermissionsRequest = new Session
                    .NewPermissionsRequest(this,PERMISSIONS);
        session.requestNewPublishPermissions(newPermissionsRequest);

        }

        Bundle postParams = new Bundle();
        postParams.putString("link", path);
        Request.Callback callback= new Request.Callback() {

            public void onCompleted(Response response) {
                Log.d("graphresponse", response.toString());
                 JSONObject graphResponse =         response.getGraphObject().getInnerJSONObject();
                String postId = null;
                try {
                    postId = graphResponse.getString("id");
                } catch (JSONException e) {
                    Log.d(
                        "JSON error "+ e.getMessage(), postId);
                }

                FacebookRequestError error = response.getError();
                if (error != null) {
                    Toast.makeText(
                         getApplicationContext(),
                         error.getErrorMessage(),
                         Toast.LENGTH_SHORT).show();
                    } else {
                        Toast.makeText(
                             getApplicationContext(), 
                             postId,
                             Toast.LENGTH_LONG).show();
                }
            }
        };


        Request request = new Request(session, "me/feed", postParams, HttpMethod.POST, callback);

        RequestAsyncTask task = new RequestAsyncTask(request);
        task.execute();


 }
public boolean isSubsetOf(Collection<String> subset, Collection<String> superset) {
for (String string : subset) {
    if (!superset.contains(string)) {
        return false;
    }
}
return true;
}
    @Override
public void onActivityResult(int requestCode, int resultCode, Intent data)
{
    super.onActivityResult(requestCode, resultCode, data);
    Session.getActiveSession().onActivityResult(this, requestCode, resultCode, data);
    Log.d("data", "data coming to onactivityresult: "+data);

}

Answer 1

这里的问题是requestNewPublishPermissions（）方法是一个异步请求，当你调用它时，它会立即返回，但此时你还没有发布权限。

您正在做的是发出“发布”请求，无论您是否具有发布权限，因此响应将产生错误而不是GraphObject结果。

如果检查response.getError（），您可能会看到权限错误（在访问Response中的任何其他内容之前，您应该首先检查该权限）。

查看HelloFacebook示例，了解如何临时缓存您要发布的信息（等待requestNewPublishPermissions完成时），并仅在您拥有所有必需权限时发布。

Answer 2

终于弄清楚

中有错误

 Request request = new Request(session, "me/feed", postParams, HttpMethod.POST, callback);

所以将其改为

 Request request = Request.newStatusUpdateRequest(session, path, callback);

希望这可以帮助有这个问题的人。所以我们不再需要创建新的Bundle .... 我们可以在上面的代码中删除create Bundle和postparams.putString行。

facebook sharing在jsonobject graphresponse中显示nullpointer异常

2 个答案: