我正在使用带有 Eclipse 的 Facebook SDK 向朋友发送请求，我想在“数据”字段中包含应用程序的其他信息。我不断收到错误 java.lang.String 无法转换为 JSON 对象，无论我尝试什么。我尝试在 JSONArray 中检索数据并在 JSONObjects 中检索特定值，但无济于事。如果您能告诉我我做错了什么，我将不胜感激。
我在下面包含了相关代码。令人敬畏的徽章和社会业力值是占位符，从此处的 facebook 教程复制：https ://developers.facebook.com/docs/android/send-requests
请求发送代码，直接来自示例（除了消息字段）：
private void sendRequestDialog() {
Bundle params = new Bundle();
params.putString("title", "Send a Request");
params.putString("message",
application.getUserId()+" has invited you to an event!");
String idHolder = ids.get(0);
for (int i = 1; i < ids.size(); i++)
{
idHolder = idHolder+"," + ids.get(i); // a for-loop to get all selected
// user ids in the recipients
// list (starting at 1 to
// prevent comma placement
// issues)
}
params.putString("to", idHolder); // comma seperated list of facebook
// IDs to preset the recipients.
params.putString("data",
"{\"badge_of_awesomeness\":\"1\"," +
"\"social_karma\":\"5\"}");
WebDialog requestsDialog = ( // initializes a web dialog, sends the
// requests parameters to the stored
// IDs, displays errors in sending
new WebDialog.RequestsDialogBuilder(this, Session.getActiveSession(),
params)).setOnCompleteListener(new OnCompleteListener() {
@Override
public void onComplete(Bundle values, FacebookException error) {
if (error != null) {
if (error instanceof FacebookOperationCanceledException) {
Toast.makeText(getApplicationContext(),
"Request cancelled", Toast.LENGTH_SHORT).show();
} else {
Toast.makeText(getApplicationContext(),
"Network Error", Toast.LENGTH_SHORT).show();
}
} else {
final String requestId = values.getString("request");
if (requestId != null) {
Toast.makeText(getApplicationContext(), "Request sent",
Toast.LENGTH_SHORT).show();
} else {
Toast.makeText(getApplicationContext(),
"Request cancelled", Toast.LENGTH_SHORT).show();
}
}
}
}).build();
requestsDialog.show();
}
其次是接收端的代码（Toast(badge_of_awesomeness) 用于测试目的）：
private void getRequestData(final String inRequestId) {
// Create a new request for an HTTP GET with the
// request ID as the Graph path.
Request request = new Request(Session.getActiveSession(),
inRequestId, null, HttpMethod.GET, new Request.Callback() {
@SuppressLint("NewApi") @Override
public void onCompleted(Response response) {
// Process the returned response
GraphObject graphObject = response.getGraphObject();
FacebookRequestError error = response.getError();
// Default message
String message = "Incoming request";
if (graphObject != null) {
// Check if there is extra data
if (graphObject.getProperty("data") != null) {
try {
// Get the data, parse info to get the key/value info
JSONObject dataObject =
new JSONObject((String)graphObject.getProperty("data"));
Toast.makeText(getApplicationContext(), dataObject.getString("badge_of_awesomeness"), 500).show();
// new JSONObject((String)graphObject.getProperty("data"));
// Get the value for the key - badge_of_awesomeness
String badge =
dataObject.getString("badge_of_awesomeness");
// Get the value for the key - social_karma
String karma =
dataObject.getString("social_karma");
// Get the sender's name
JSONObject fromObject =
(JSONObject) graphObject.getProperty("from");
String sender = fromObject.getString("name");
String title = sender+" sent you a gift";
// Create the text for the alert based on the sender
// and the data
message = title + "\n\n" +
"Badge: " + badge +
" Karma: " + karma;
} catch (JSONException e) {
message = "Error getting request infoJSON";
Log.e("!", "!", e);
}
} else if (error != null) {
message = "Error getting request info";
}
}
Toast.makeText(getApplicationContext(),
message,
Toast.LENGTH_LONG).show();
}
});
// Execute the request asynchronously.
Request.executeBatchAsync(request);
}
JSON：
{
"id": "493703870648580",
"application": {
"name": "Send Requests How To",
"id": "403223126407920"
},
"to": {
"name": "Chris Abe Colm",
"id": "100003086810435"
},
"from": {
"name": "Christine Abernathy",
"id": "1424840234"
},
"data": "{\"badge_of_awesomeness\":\"1\",\"social_karma\":\"5\"}",
"message": "Learn how to make your Android apps social",
"created_time": "2012-10-07T17:29:57+0000"
}
日志猫：
06-20 17:33:47.413: E/!(31515): !
06-20 17:33:47.413: E/!(31515): org.json.JSONException: Value nullandroid.widget.EditText@4164a490android.widget.EditText@414d9928 of type java.lang.String cannot be converted to JSONObject
06-20 17:33:47.413: E/!(31515): at org.json.JSON.typeMismatch(JSON.java:111)
06-20 17:33:47.413: E/!(31515): at org.json.JSONObject.<init>(JSONObject.java:159)
06-20 17:33:47.413: E/!(31515): at org.json.JSONObject.<init>(JSONObject.java:172)
06-20 17:33:47.413: E/!(31515): at hro.informatica.gameplanner.GamePlannerMain$10.onCompleted(GamePlannerMain.java:482)
06-20 17:33:47.413: E/!(31515): at com.facebook.Request$4.run(Request.java:1725)
06-20 17:33:47.413: E/!(31515): at android.os.Handler.handleCallback(Handler.java:733)
06-20 17:33:47.413: E/!(31515): at android.os.Handler.dispatchMessage(Handler.java:95)
06-20 17:33:47.413: E/!(31515): at android.os.Looper.loop(Looper.java:212)
06-20 17:33:47.413: E/!(31515): at android.app.ActivityThread.main(ActivityThread.java:5151)
06-20 17:33:47.413: E/!(31515): at java.lang.reflect.Method.invokeNative(Native Method)
06-20 17:33:47.413: E/!(31515): at java.lang.reflect.Method.invoke(Method.java:515)
06-20 17:33:47.413: E/!(31515): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:878)
06-20 17:33:47.413: E/!(31515): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694)
06-20 17:33:47.413: E/!(31515): at dalvik.system.NativeStart.main(Native Method)
06-20 17:33:47.423: W/ResourceType(31515): CREATING STRING CACHE OF 44 bytes
我真的不明白我在这里做错了什么，我花了一整天（嗯，整个下午）倾注于 stackoverflow 尝试不同的解决方案。我可能在某个地方犯了一个明显的错误，但我找不到它。我真的卡住了，请帮帮我！