Android - JSONException No value for

问题

I know that there are several questions posted on here with the same topic and error, but none of them indicate the same problem as mine, so I decided to post my question here, hoping that someone would help me point out the cause. So I'm trying to implement the login feature in my app and here's the code:

if (tag.equalsIgnoreCase(login_tag)){
                // check for login response
                try {
                    if (json.getString(KEY_SUCCESS) != null) {
                        String res = json.getString(KEY_SUCCESS);
                        if(Integer.parseInt(res) == 1){
                            // user successfully logged in
                            // Store user details in SQLite Database
                            DatabaseHandler db = new DatabaseHandler(mContext);
                            JSONObject json_user = json.getJSONObject("user");

                            // Clear all previous data in database
                            logoutUser(mContext);
                            Toast.makeText(mContext, json.toString(3), Toast.LENGTH_LONG).show();
                            db.addUser(json_user.getString(KEY_EMAIL), json_user.getString(KEY_NAME), json.getString(KEY_UID), json.getString(KEY_AVA), json_user.getString(KEY_BDAY), json_user.getString(KEY_COUNTRY), json_user.getString(KEY_PREF), json_user.getString(KEY_SPEND));  

                            // Launch Dashboard Screen
                            Intent dashboard = new Intent(mContext, DashboardActivity.class);

                            // Close all views before launching Dashboard
                            dashboard.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
                            mContext.startActivity(dashboard);

                            // Close Login Screen
                            ((Activity) mContext).finish();
                        }
                    }
                } catch (JSONException e) {
                    e.printStackTrace();
                }
            }

And this is the JSON response I got when logging in:

{
    "tag": "login",
    "success": 1,
    "error": 0,
    "uid": "5123",
    "user": {
        "email": "abcxyz@gmail.com",
        "name": "abc",
        "avatar": "avatars/img_hzsxda_2013-03-18-11-03-33.jpg",
        "bday": "1991-02-01",
        "country": "Australia",
        "preferences": "none",
        "spending": "none"
    }
}

So apparently there is a value for avatar, but I still got this warning in my logcat:

03-18 12:06:36.972: W/System.err(24574): org.json.JSONException: No value for avatar

Since no value avatar is got, I can't complete addUser, hence login fails. Please help me find the error and how to solve it. Thank you.

回答1:

You are using the wrong object to get avatar value here json.getString(KEY_AVA). It should be json_user.getString(KEY_AVA).

Also, you can use optString instead of getString which just returns null if value doesn't exist, instead of throwing an exception.

来源：https://stackoverflow.com/questions/15477304/android-jsonexception-no-value-for

标签

java

android

json

jsonexception