我是Android编程的新手。我试图通过解析它在我的Android应用程序中干预用户ID的值，但错误说没有用户的值。如何从android中的json数据中获取输入？我在下面附上了我的logcat错误。任何人都可以帮帮我吗？先谢谢
"status": "SUCCESS",
"msg": "Login Successful",
"data": {
"user": {
"id": "6",
"first_name": "e",
"last_name": "ff",
"address": "dr",
"mobile": "55",
"email": "rokes1990@live.com",
"password": "4124bc0a9335c27f086f24ba207a4912",
"pwd_reset_key": "",
"name_on_card": "",
"card_number": "",
"expiry_date": "",
"cvv": "",
"tdatetime": "2014-07-11 02:55:08"
}
}
LogCat错误：
09-05 03:36:00.567: D/dalvikvm(2227): GC_FOR_ALLOC freed 379K, 8% free 5765K/6220K, paused 76ms, total 82ms
09-05 03:36:02.077: W/Response(2227): {"GET":[],"POST":{"action":"login","app_secret":"jkhljkUILJGJkljhkjUGLG87796587687HGKJhghkjKUYGKJHjhgjUYGKUY7865876hgKUYGK","email":"rokes1990@live.com","password":"aa"},"status":"SUCCESS","msg":"Login Successful","data":{"user":{"id":"6","first_name":"e","last_name":"ff","address":"dr","mobile":"55","email":"rokes1990@live.com","password":"4124bc0a9335c27f086f24ba207a4912","pwd_reset_key":"","name_on_card":"","card_number":"","expiry_date":"","cvv":"","tdatetime":"2014-07-11 02:55:08"}}}
09-05 03:36:02.107: W/System.err(2227): org.json.JSONException: No value for user
09-05 03:36:02.117: W/System.err(2227): at org.json.JSONObject.get(JSONObject.java:355)
09-05 03:36:02.117: W/System.err(2227): at org.json.JSONObject.getString(JSONObject.java:515)
09-05 03:36:02.147: W/System.err(2227): at example.atlcitylimo.Main.postLoginData(Main.java:116)
09-05 03:36:02.147: W/System.err(2227): at example.atlcitylimo.Main.onClick(Main.java:181)
09-05 03:36:02.147: W/System.err(2227): at android.view.View.performClick(View.java:4438)
09-05 03:36:02.147: W/System.err(2227): at android.view.View$PerformClick.run(View.java:18422)
09-05 03:36:02.147: W/System.err(2227): at android.os.Handler.handleCallback(Handler.java:733)
09-05 03:36:02.147: W/System.err(2227): at android.os.Handler.dispatchMessage(Handler.java:95)
09-05 03:36:02.147: W/System.err(2227): at android.os.Looper.loop(Looper.java:136)
09-05 03:36:02.157: W/System.err(2227): at android.app.ActivityThread.main(ActivityThread.java:5017)
09-05 03:36:02.157: W/System.err(2227): at java.lang.reflect.Method.invokeNative(Native Method)
09-05 03:36:02.157: W/System.err(2227): at java.lang.reflect.Method.invoke(Method.java:515)
09-05 03:36:02.157: W/System.err(2227): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
09-05 03:36:02.157: W/System.err(2227): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
09-05 03:36:02.157: W/System.err(2227): at dalvik.system.NativeStart.main(Native Method)
答案 0 :(得分：1)
protected String getId(String result) {
try {
JSONObject jsonObject = new JSONObject(result);
JSONObject data = new JSONObject(jsonObject.getString("data"));
JSONObject user = new JSONObject(jsonObject.getString("user"));
String id = user.getString("id");
return id;
}catch (Exception e) {
Log.d("error", e.getLocalizedMessage());
}
return null;
}
答案 1 :(得分：0)
您可以使用Volley解析json字符串。检查＆＃34;发出JSON请求＆＃34;在以下链接中：
http://www.androidhive.info/2014/05/android-working-with-volley-library-1/
Volley提供了一个简单的json请求。如果您希望响应中有json对象，则应使用JsonObjectRequest类，或者如果响应是json数组，则应使用JsonArrayRequest类。 StringRequest类将用于获取任何类型的字符串数据。响应可以是json，xml，html或纯文本。
您可以从JsonObjectRequest开始获取JSONObject：
JsonObjectRequest jsonObjReq = new JsonObjectRequest(Method.GET, url, null,
new Response.Listener<JSONObject>() {
@Override
public void onResponse(JSONObject response) {
//response is the JSONObject that you get from the request
//you can play with that request to get the exact info you want
String status = response.getString("status");
String msg = response.getString("msg");
JSONObject data = null;
try{
data = response.getJSONObject("data");
}catch (JSONException e1) {
e1.printStackTrace();
}
JSONObject user = null;
try{
user = data.getJSONObject("user");
}catch (JSONException e1) {
e1.printStackTrace();
}
String id = user.getString("id");
String first_name = user.getString("first_name");
//and goes on for the rest of the user info
}
}, new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
VolleyLog.d(TAG, "Error: " + error.getMessage());
}
});
此外，您还需要将此请求添加到请求队列
// Adding request to request queue
AppController.getInstance().addToRequestQueue(req, tag_json_arry);
您的AppController类如下：
import android.app.Application;
import android.text.TextUtils;
import com.android.volley.Request;
import com.android.volley.RequestQueue;
import com.android.volley.toolbox.ImageLoader;
import com.android.volley.toolbox.Volley;
public class AppController extends Application {
public static final String TAG = AppController.class
.getSimpleName();
private RequestQueue mRequestQueue;
private ImageLoader mImageLoader;
private static AppController mInstance;
@Override
public void onCreate() {
super.onCreate();
mInstance = this;
}
public static synchronized AppController getInstance() {
return mInstance;
}
public RequestQueue getRequestQueue() {
if (mRequestQueue == null) {
mRequestQueue = Volley.newRequestQueue(getApplicationContext());
}
return mRequestQueue;
}
public ImageLoader getImageLoader() {
getRequestQueue();
if (mImageLoader == null) {
mImageLoader = new ImageLoader(this.mRequestQueue,
new LruBitmapCache());
}
return this.mImageLoader;
}
public <T> void addToRequestQueue(Request<T> req, String tag) {
// set the default tag if tag is empty
req.setTag(TextUtils.isEmpty(tag) ? TAG : tag);
getRequestQueue().add(req);
}
public <T> void addToRequestQueue(Request<T> req) {
req.setTag(TAG);
getRequestQueue().add(req);
}
public void cancelPendingRequests(Object tag) {
if (mRequestQueue != null) {
mRequestQueue.cancelAll(tag);
}
}
}
最后在您的Manifest.xml中添加以下版本<application>标记
<application
android:name="info.androidhive.volleyexamples.app.AppController"