JSON 片段解析

JSON parsing in fragmant

我正在尝试从服务器解析 json,当我使用 Activity 而不是 Fragment 时我成功了。现在我遇到错误,我在网上搜索过,但我无法解决。

ContentFragmant.java

import android.app.ProgressDialog;
import android.content.Intent;
import android.os.AsyncTask;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.SimpleAdapter;
import android.widget.TextView;

import xxx.FUNCTIONS.GetServerAddress;
import xxx.FUNCTIONS.JSONParser;
import xxx.WORKERS.DetailWorkerActivity;

import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;

import cz.msebera.android.httpclient.NameValuePair;

/**
 * Created by Admin on 04-06-2015.
 */
public class ContentFragment extends Fragment {

    // Progress Dialog
    private ProgressDialog pDialog;
    // Creating JSON Parser object
    JSONParser jParser = new JSONParser();
    ArrayList<HashMap<String, String>> workersList;
    static GetServerAddress gServer;
    // url to get all workers list
    private static String url_all_workers = gServer.SERVER_ADRESS_WORKERS + "get_all_workers.php";
    // JSON Node names
    private static final String TAG_SUCCESS = "success";
    private static final String TAG_WORKERS = "workers";
    private static final String TAG_PID = "pid";
    private static final String TAG_NAME = "name";
    // workers JSONArray
    JSONArray workers = null;

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        View v = inflater.inflate(R.layout.w_all_workers,container,false);
        return v;
    }

    public void onViewCreated(View v, Bundle savedInstanceState) {
        super.onViewCreated(v, savedInstanceState);

        workersList = new ArrayList<HashMap<String, String>>();

        // Loading workers in Background Thread
        new LoadAllProducts().execute();

    }


    @Override
    public void onActivityResult(int requestCode, int resultCode, Intent data) {
    super.onActivityResult(requestCode, resultCode, data);
        // if result code 100
        if (resultCode == 100) {
            // if result code 100 is received
            // means user edited/deleted worker
        // reload this screen again
        Intent intent = getActivity().getIntent();
        getActivity().finish();
        startActivity(intent);
    }

}

/**
 * Background Async Task to Load all worker by making HTTP Request
 * */
    class LoadAllProducts extends AsyncTask<String, String, String> {
    /**
     * Before starting background thread Show Progress Dialog
     * */
    @Override
    protected void onPreExecute() {
        super.onPreExecute();
        pDialog = new ProgressDialog(getActivity());
        pDialog.setMessage("Loading workers. Please wait...");
        pDialog.setIndeterminate(false);
        pDialog.setCancelable(false);
        pDialog.show();
    }

    /**
     * getting All workers from url
     * */


    protected String doInBackground(String... args) {


        // Building Parameters
        List<NameValuePair> params = new ArrayList<NameValuePair>();
        // getting JSON string from URL
        JSONObject json = jParser.makeHttpRequest(url_all_workers, "GET", params);   // I guess ERROR is here

        // Check your log cat for JSON reponse
        Log.d("All Products: ", json.toString());

        try {
            // Checking for SUCCESS TAG
            int success = json.getInt(TAG_SUCCESS);

            if (success == 1) {
                // workers found
                // Getting Array of Products
                workers = json.getJSONArray(TAG_WORKERS);

                // looping through All Products
                for (int i = 0; i < workers.length(); i++) {
                    JSONObject c = workers.getJSONObject(i);

                    // Storing each json item in variable
                    String id = c.getString(TAG_PID);
                    String name = c.getString(TAG_NAME);

                    // creating new HashMap
                    HashMap<String, String> map = new HashMap<String, String>();

                    // adding each child node to HashMap key => value
                    map.put(TAG_PID, id);
                    map.put(TAG_NAME, name);

                    // adding HashList to ArrayList
                    workersList.add(map);
                }
            } else {
                // no workers found
                // Launch Add New worker Activity

            }
        } catch (JSONException e) {
            e.printStackTrace();
        }

        return null;
    }

    /**
     * After completing background task Dismiss the progress dialog
     * **/
    protected void onPostExecute(String file_url) {
        // dismiss the dialog after getting all workers
        pDialog.dismiss();
        // updating UI from Background Thread
        getActivity().runOnUiThread(new Runnable() {
            public void run() {
                /**
                 * Updating parsed JSON data into ListView
                 * */
               ListView list = (ListView)getView().findViewById(R.id.list);
                ListAdapter adapter = new SimpleAdapter(
                        getActivity(), workersList,
                        R.layout.t_list_item, new String[]{TAG_PID,
                        TAG_NAME},
                        new int[]{R.id.pid, R.id.name});
                // updating listview
                list.setAdapter(adapter);
                // on seleting single worker
                // launching Edit Product Screen
                list.setOnItemClickListener(new AdapterView.OnItemClickListener() {

                    @Override
                    public void onItemClick(AdapterView<?> parent, View view,
                                            int position, long id) {
                        // getting values from selected ListItem
                        String pid = ((TextView) view.findViewById(R.id.pid)).getText()
                                .toString();

                        // Starting new intent
                        Intent in = new Intent(getActivity(),
                                DetailWorkerActivity.class);
                        // sending pid to next activity
                        in.putExtra(TAG_PID, pid);

                        // starting new activity and expecting some response back
                        startActivityForResult(in, 100);
                    }
                });
            }
        });

    }

}
}

Jsonparser.java

import android.util.Log;

import org.json.JSONException;
import org.json.JSONObject;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.UnsupportedEncodingException;
import java.util.List;

import cz.msebera.android.httpclient.HttpEntity;
import cz.msebera.android.httpclient.HttpResponse;
import cz.msebera.android.httpclient.NameValuePair;
import cz.msebera.android.httpclient.client.ClientProtocolException;
import cz.msebera.android.httpclient.client.entity.UrlEncodedFormEntity;
import cz.msebera.android.httpclient.client.methods.HttpGet;
import cz.msebera.android.httpclient.client.methods.HttpPost;
import cz.msebera.android.httpclient.client.utils.URLEncodedUtils;
import cz.msebera.android.httpclient.impl.client.DefaultHttpClient;


public class JSONParser {

    static InputStream is = null;
    static JSONObject jObj = null;
    static String json = "";

    // constructor
    public JSONParser() {

    }

    // function get json from url
    // by making HTTP POST or GET mehtod
    public JSONObject makeHttpRequest(String url, String method,
            List<NameValuePair> params)
    {

        // Making HTTP request
        try {

            // check for request method
            if(method == "POST"){
                // request method is POST
                // defaultHttpClient
                DefaultHttpClient httpClient = new DefaultHttpClient();
                HttpPost httpPost = new HttpPost(url);
                httpPost.setEntity(new UrlEncodedFormEntity(params));

                HttpResponse httpResponse = httpClient.execute(httpPost);
                HttpEntity httpEntity = httpResponse.getEntity();
                is = httpEntity.getContent();

            }else if(method == "GET"){
                // request method is GET
                DefaultHttpClient httpClient = new DefaultHttpClient();
                String paramString = URLEncodedUtils.format(params, "utf-8");
                url += "?" + paramString;
                HttpGet httpGet = new HttpGet(url);

                HttpResponse httpResponse = httpClient.execute(httpGet);
                HttpEntity httpEntity = httpResponse.getEntity();
                is = httpEntity.getContent();
            }           


        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        } catch (ClientProtocolException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }

        try {
            BufferedReader reader = new BufferedReader(new InputStreamReader(
                    is, "iso-8859-1"), 8);
            StringBuilder sb = new StringBuilder();
            String line = null;
            while ((line = reader.readLine()) != null) {
                sb.append(line + "\n");
            }
            is.close();
            json = sb.toString();
        } catch (Exception e) {
            Log.e("Buffer Error", "Error converting result " + e.toString());
        }

        // try parse the string to a JSON object
        try {
            jObj = new JSONObject(json);
        } catch (JSONException e) {
            Log.e("JSON Parser", "Error parsing data " + e.toString());
        }
        // return JSON String
        return jObj;

    }
}

错误列表

    : FATAL EXCEPTION: AsyncTask #1
: java.lang.RuntimeException: An error occured while executing doInBackground()
: at android.os.AsyncTask.done(AsyncTask.java:299)
: at java.util.concurrent.FutureTask.finishCompletion(FutureTask.java:352)
: at java.util.concurrent.FutureTask.setException(FutureTask.java:219)
: at java.util.concurrent.FutureTask.run(FutureTask.java:239)
: at android.os.AsyncTask$SerialExecutor.run(AsyncTask.java:230)
: at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1080)
: at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:573)
: at java.lang.Thread.run(Thread.java:841)
: Caused by: java.lang.SecurityException: Permission denied (missing INTERNET permission?)
: at java.net.InetAddress.lookupHostByName(InetAddress.java:418)
: at java.net.InetAddress.getAllByNameImpl(InetAddress.java:236)
: at java.net.InetAddress.getAllByName(InetAddress.java:214)
: at cz.msebera.android.httpclient.impl.conn.SystemDefaultDnsResolver.resolve(SystemDefaultDnsResolver.java:45)
: at cz.msebera.android.httpclient.impl.conn.DefaultClientConnectionOperator.resolveHostname(DefaultClientConnectionOperator.java:259)
: at cz.msebera.android.httpclient.impl.conn.DefaultClientConnectionOperator.openConnection(DefaultClientConnectionOperator.java:159)
: at cz.msebera.android.httpclient.impl.conn.ManagedClientConnectionImpl.open(ManagedClientConnectionImpl.java:304)
: at cz.msebera.android.httpclient.impl.client.DefaultRequestDirector.tryConnect(DefaultRequestDirector.java:611)
: at cz.msebera.android.httpclient.impl.client.DefaultRequestDirector.execute(DefaultRequestDirector.java:446)
: at cz.msebera.android.httpclient.impl.client.AbstractHttpClient.doExecute(AbstractHttpClient.java:879)
: at cz.msebera.android.httpclient.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:82)
: at cz.msebera.android.httpclient.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:107)
: at xxx.FUNCTIONS.JSONParser.makeHttpRequest(JSONParser.java:65)
: at xxx.ContentFragment$LoadAllProducts.doInBackground(ContentFragment.java:115)
: at xxx.ContentFragment$LoadAllProducts.doInBackground(ContentFragment.java:90)
: at android.os.AsyncTask.call(AsyncTask.java:287)
: at java.util.concurrent.FutureTask.run(FutureTask.java:234)
: at android.os.AsyncTask$SerialExecutor.run(AsyncTask.java:230) 
: at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1080) 
: at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:573) 
: at java.lang.Thread.run(Thread.java:841) 
: Caused by: libcore.io.GaiException: getaddrinfo failed: EAI_NODATA (No address associated with hostname)
: at libcore.io.Posix.getaddrinfo(Native Method)
: at libcore.io.ForwardingOs.getaddrinfo(ForwardingOs.java:61)
: at java.net.InetAddress.lookupHostByName(InetAddress.java:405)
: at java.net.InetAddress.getAllByNameImpl(InetAddress.java:236) 
: at java.net.InetAddress.getAllByName(InetAddress.java:214) 
: at cz.msebera.android.httpclient.impl.conn.SystemDefaultDnsResolver.resolve(SystemDefaultDnsResolver.java:45) 
: at cz.msebera.android.httpclient.impl.conn.DefaultClientConnectionOperator.resolveHostname(DefaultClientConnectionOperator.java:259) 
: at cz.msebera.android.httpclient.impl.conn.DefaultClientConnectionOperator.openConnection(DefaultClientConnectionOperator.java:159) 
: at cz.msebera.android.httpclient.impl.conn.ManagedClientConnectionImpl.open(ManagedClientConnectionImpl.java:304) 
: at cz.msebera.android.httpclient.impl.client.DefaultRequestDirector.tryConnect(DefaultRequestDirector.java:611) 
: at cz.msebera.android.httpclient.impl.client.DefaultRequestDirector.execute(DefaultRequestDirector.java:446) 
: at cz.msebera.android.httpclient.impl.client.AbstractHttpClient.doExecute(AbstractHttpClient.java:879) 
: at cz.msebera.android.httpclient.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:82) 
: at cz.msebera.android.httpclient.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:107) 
: at com.android4dev.navigationview.FUNCTIONS.JSONParser.makeHttpRequest(JSONParser.java:65) 
: at com.android4dev.navigationview.ContentFragment$LoadAllProducts.doInBackground(ContentFragment.java:115) 
: at com.android4dev.navigationview.ContentFragment$LoadAllProducts.doInBackground(ContentFragment.java:90) 
: at android.os.AsyncTask.call(AsyncTask.java:287) 
: at java.util.concurrent.FutureTask.run(FutureTask.java:234) 
: at android.os.AsyncTask$SerialExecutor.run(AsyncTask.java:230) 
: at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1080) 
: at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:573) 
: at java.lang.Thread.run(Thread.java:841) 
: Caused by: libcore.io.ErrnoException: getaddrinfo failed: EACCES (Permission denied)
: at libcore.io.Posix.getaddrinfo(Native Method) 
: at libcore.io.ForwardingOs.getaddrinfo(ForwardingOs.java:61) 
: at java.net.InetAddress.lookupHostByName(InetAddress.java:405) 
: at java.net.InetAddress.getAllByNameImpl(InetAddress.java:236) 
: at java.net.InetAddress.getAllByName(InetAddress.java:214) 
: at cz.msebera.android.httpclient.impl.conn.SystemDefaultDnsResolver.resolve(SystemDefaultDnsResolver.java:45) 
: at cz.msebera.android.httpclient.impl.conn.DefaultClientConnectionOperator.resolveHostname(DefaultClientConnectionOperator.java:259) 
: at cz.msebera.android.httpclient.impl.conn.DefaultClientConnectionOperator.openConnection(DefaultClientConnectionOperator.java:159) 
: at cz.msebera.android.httpclient.impl.conn.ManagedClientConnectionImpl.open(ManagedClientConnectionImpl.java:304) 
: at cz.msebera.android.httpclient.impl.client.DefaultRequestDirector.tryConnect(DefaultRequestDirector.java:611) 
: at cz.msebera.android.httpclient.impl.client.DefaultRequestDirector.execute(DefaultRequestDirector.java:446) 
: at cz.msebera.android.httpclient.impl.client.AbstractHttpClient.doExecute(AbstractHttpClient.java:879) 
: at cz.msebera.android.httpclient.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:82) 
: at cz.msebera.android.httpclient.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:107) 
: at com.android4dev.navigationview.FUNCTIONS.JSONParser.makeHttpRequest(JSONParser.java:65) 
: at com.android4dev.navigationview.ContentFragment$LoadAllProducts.doInBackground(ContentFragment.java:115) 
: at com.android4dev.navigationview.ContentFragment$LoadAllProducts.doInBackground(ContentFragment.java:90) 
: at android.os.AsyncTask.call(AsyncTask.java:287) 
: at java.util.concurrent.FutureTask.run(FutureTask.java:234) 
: at android.os.AsyncTask$SerialExecutor.run(AsyncTask.java:230) 
: at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1080) 
: at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:573) 
: at java.lang.Thread.run(Thread.java:841) 
 W/ActivityManager: Force finishing activity com.android4dev.navigationview/.MainActivity
D/dalvikvm: GC_FOR_ALLOC freed 362K, 24% free 7421K/9676K, paused 14ms, total 19ms
 I/qtaguid: Failed write_ctrl(s 1 10023) res=-1 errno=1
 W/NetworkManagementSocketTagger: setKernelCountSet(10023, 1) failed with errno -1
W/EGL_genymotion: eglSurfaceAttrib not implemented
 I/qtaguid: Failed write_ctrl(s 0 10080) res=-1 errno=1
W/NetworkManagementSocketTagger: setKernelCountSet(10080, 0) failed with errno -1
 Activity com.android4dev.navigationview.MainActivity has leaked window com.android.internal.policy.impl.PhoneWindow$DecorView{52918c00 V.E..... R......D 0,0-614,96} that was originally added here
 android.view.WindowLeaked: Activity com.android4dev.navigationview.MainActivity has leaked window com.android.internal.policy.impl.PhoneWindow$DecorView{52918c00 V.E..... R......D 0,0-614,96} that was originally added here
 at android.view.ViewRootImpl.<init>(ViewRootImpl.java:345)
 at android.view.WindowManagerGlobal.addView(WindowManagerGlobal.java:239)
 at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:69)
 at android.app.Dialog.show(Dialog.java:281)
 at com.android4dev.navigationview.ContentFragment$LoadAllProducts.onPreExecute(ContentFragment.java:101)
 at android.os.AsyncTask.executeOnExecutor(AsyncTask.java:586)
 at android.os.AsyncTask.execute(AsyncTask.java:534)
 at com.android4dev.navigationview.ContentFragment.onViewCreated(ContentFragment.java:65)
 at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:973)
 at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1138)
 at android.support.v4.app.BackStackRecord.run(BackStackRecord.java:740)
 at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1501)
 at android.support.v4.app.FragmentManagerImpl.run(FragmentManager.java:458)
 at android.os.Handler.handleCallback(Handler.java:730)
 at android.os.Handler.dispatchMessage(Handler.java:92)
 at android.os.Looper.loop(Looper.java:137)
 at android.app.ActivityThread.main(ActivityThread.java:5103)
 at java.lang.reflect.Method.invokeNative(Native Method)
 at java.lang.reflect.Method.invoke(Method.java:525)
 at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:737)
 at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
 at dalvik.system.NativeStart.main(Native Method))
 at android.os.Looper.loop(Looper.java:137)
 at android.app.ActivityThread.main(ActivityThread.java:5103)
 at java.lang.reflect.Method.invokeNative(Native Method)
 at java.lang.reflect.Method.invoke(Method.java:525)
 at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:737)
 at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
 at dalvik.system.NativeStart.main(Native Method)

您的 AndroidManifest.xml 似乎未授予您的应用访问互联网的权限。

您的错误日志指出:

Permission denied (missing INTERNET permission?)

取自 Android 文档 http://developer.android.com/reference/android/Manifest.permission.html#INTERNET

String | INTERNET | Allows applications to open network sockets.

将以下行添加到您的 AndroidManifest.xml 以允许访问互联网:

<uses-permission android:name="android.permission.INTERNET" />