Question

我有一个Android项目，我应该用json链接到服务器，然后收到的信息显示在自定义列表视图中。

此代码的工作原理如图1所示。但是，我使用的json的形式类似于图2所示。

在另一个世界中，我使用的json没有（＆＃34; feed＆＃34; :)。

现在的问题是如何更改代码以便链接到我的json。

感谢。

MainActivity.java
package info.androidhive.listviewfeed;

import info.androidhive.listviewfeed.adapter.FeedListAdapter;
import info.androidhive.listviewfeed.app.AppController;
import info.androidhive.listviewfeed.data.FeedItem;

import java.io.UnsupportedEncodingException;
import java.util.ArrayList;
import java.util.List;

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

import android.annotation.SuppressLint;
import android.app.Activity;
import android.graphics.Color;
import android.graphics.drawable.ColorDrawable;
import android.os.Bundle;
import android.view.Menu;
import android.widget.ListView;

import com.android.volley.Cache;
import com.android.volley.Cache.Entry;
import com.android.volley.Request.Method;
import com.android.volley.Response;
import com.android.volley.VolleyError;
import com.android.volley.VolleyLog;
import com.android.volley.toolbox.JsonObjectRequest;

public class MainActivity extends Activity {
    private static final String TAG = MainActivity.class.getSimpleName();
    private ListView listView;
    private FeedListAdapter listAdapter;
    private List<FeedItem> feedItems;
    private String URL_FEED = "http://api.androidhive.info/feed/feed.json";

    @SuppressLint("NewApi")
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        listView = (ListView) findViewById(R.id.list);

        feedItems = new ArrayList<FeedItem>();

        listAdapter = new FeedListAdapter(this, feedItems);
        listView.setAdapter(listAdapter);

        // These two lines not needed,
        // just to get the look of facebook (changing background color & hiding the icon)
        getActionBar().setBackgroundDrawable(new ColorDrawable(Color.parseColor("#3b5998")));
        getActionBar().setIcon(
                   new ColorDrawable(getResources().getColor(android.R.color.transparent)));

        // We first check for cached request
        Cache cache = AppController.getInstance().getRequestQueue().getCache();
        Entry entry = cache.get(URL_FEED);
        if (entry != null) {
            // fetch the data from cache
            try {
                String data = new String(entry.data, "UTF-8");
                try {
                    parseJsonFeed(new JSONObject(data));
                } catch (JSONException e) {
                    e.printStackTrace();
                }
            } catch (UnsupportedEncodingException e) {
                e.printStackTrace();
            }

        } else {
            // making fresh volley request and getting json
            JsonObjectRequest jsonReq = new JsonObjectRequest(Method.GET,
                    URL_FEED, null, new Response.Listener<JSONObject>() {

                        @Override
                        public void onResponse(JSONObject response) {
                            VolleyLog.d(TAG, "Response: " + response.toString());
                            if (response != null) {
                                parseJsonFeed(response);
                            }
                        }
                    }, new Response.ErrorListener() {

                        @Override
                        public void onErrorResponse(VolleyError error) {
                            VolleyLog.d(TAG, "Error: " + error.getMessage());
                        }
                    });

            // Adding request to volley request queue
            AppController.getInstance().addToRequestQueue(jsonReq);
        }

    }

    /**
     * Parsing json reponse and passing the data to feed view list adapter
     * */
    private void parseJsonFeed(JSONObject response) {
        try {
            JSONArray feedArray = response.getJSONArray("feed");

            for (int i = 0; i < feedArray.length(); i++) {
                JSONObject feedObj = (JSONObject) feedArray.get(i);

                FeedItem item = new FeedItem();
                item.setId(feedObj.getInt("id"));
                item.setName(feedObj.getString("name"));

                // Image might be null sometimes
                String image = feedObj.isNull("image") ? null : feedObj
                        .getString("image");
                item.setImge(image);
                item.setStatus(feedObj.getString("status"));
                item.setProfilePic(feedObj.getString("profilePic"));
                item.setTimeStamp(feedObj.getString("timeStamp"));

                // url might be null sometimes
                String feedUrl = feedObj.isNull("url") ? null : feedObj
                        .getString("url");
                item.setUrl(feedUrl);

                feedItems.add(item);
            }

            // notify data changes to list adapater
            listAdapter.notifyDataSetChanged();
        } catch (JSONException e) {
            e.printStackTrace();
        }
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }

}

图1：

  {
    "feed": [
        {
            "id": 1,
            "name": "National Geographic Channel",
            "image": "http://api.androidhive.info/feed/img/cosmos.jpg",
            "status": "\"Science is a beautiful and emotional human endeavor,\" says Brannon Braga, executive producer and director. \"And Cosmos is all about making science an experience.\"",
            "profilePic": "http://api.androidhive.info/feed/img/nat.jpg",
            "timeStamp": "1403375851930",
            "url": null
        },
        {
            "id": 2,
            "name": "TIME",
            "image": "http://api.androidhive.info/feed/img/time_best.jpg",
            "status": "30 years of Cirque du Soleil's best photos",
            "profilePic": "http://api.androidhive.info/feed/img/time.png",
            "timeStamp": "1403375851930",
            "url": "http://ti.me/1qW8MLB"
        },
        {
            "id": 3,
            "name": "Discovery",
            "image": "http://api.androidhive.info/feed/img/discovery_mos.jpg",
            "status": "A team of Austrian scientists has developed a laser system that causes fruit flies to dance.",
            "profilePic": "http://api.androidhive.info/feed/img/discovery.jpg",
            "timeStamp": "1403375851930",
            "url": "http://dsc.tv/xmMxD"
        }
    ]
}

图2：

       [
            {
                "id": 1,
                "name": "National Geographic Channel",
                "image": "http://api.androidhive.info/feed/img/cosmos.jpg",
                "status": "\"Science is a beautiful and emotional human endeavor,\" says Brannon Braga, executive producer and director. \"And Cosmos is all about making science an experience.\"",
                "profilePic": "http://api.androidhive.info/feed/img/nat.jpg",
                "timeStamp": "1403375851930",
                "url": null
            },
            {
                "id": 2,
                "name": "TIME",
                "image": "http://api.androidhive.info/feed/img/time_best.jpg",
                "status": "30 years of Cirque du Soleil's best photos",
                "profilePic": "http://api.androidhive.info/feed/img/time.png",
                "timeStamp": "1403375851930",
                "url": "http://ti.me/1qW8MLB"
            },
            {
                "id": 3,
                "name": "Discovery",
                "image": "http://api.androidhive.info/feed/img/discovery_mos.jpg",
                "status": "A team of Austrian scientists has developed a laser system that causes fruit flies to dance.",
                "profilePic": "http://api.androidhive.info/feed/img/discovery.jpg",
                "timeStamp": "1403375851930",
                "url": "http://dsc.tv/xmMxD"
            }
        ]

Answer 1

试试这个

public class MainActivity extends Activity {
private static final String TAG = MainActivity.class.getSimpleName();
private ListView listView;
private FeedListAdapter listAdapter;
private List<FeedItem> feedItems;
private String URL_FEED = "http://api.androidhive.info/feed/feed.json";

@SuppressLint("NewApi")
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    listView = (ListView) findViewById(R.id.list);

    feedItems = new ArrayList<FeedItem>();

    listAdapter = new FeedListAdapter(this, feedItems);
    listView.setAdapter(listAdapter);

    // These two lines not needed,
    // just to get the look of facebook (changing background color & hiding the icon)
    getActionBar().setBackgroundDrawable(new ColorDrawable(Color.parseColor("#3b5998")));
    getActionBar().setIcon(
               new ColorDrawable(getResources().getColor(android.R.color.transparent)));

    // We first check for cached request
    Cache cache = AppController.getInstance().getRequestQueue().getCache();
    Entry entry = cache.get(URL_FEED);
    if (entry != null) {
        // fetch the data from cache
        try {
            String data = new String(entry.data, "UTF-8");
            try {
                parseJsonFeed(new JSONArray(data));
            } catch (JSONException e) {
                e.printStackTrace();
            }
        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        }

    } else {
        // making fresh volley request and getting json
        JsonArrayRequest jsonReq = new JsonArrayRequest(Method.GET,
                URL_FEED, null, new Response.Listener<JSONArray>() {

                    @Override
                    public void onResponse(JSONArray response) {
                        VolleyLog.d(TAG, "Response: " + response.toString());
                        if (response != null) {
                            parseJsonFeed(response);
                        }
                    }
                }, new Response.ErrorListener() {

                    @Override
                    public void onErrorResponse(VolleyError error) {
                        VolleyLog.d(TAG, "Error: " + error.getMessage());
                    }
                });

        // Adding request to volley request queue
        AppController.getInstance().addToRequestQueue(jsonReq);
    }

}

/**
 * Parsing json reponse and passing the data to feed view list adapter
 * */
private void parseJsonFeed(JSONArray feedArray) {
    try {

        for (int i = 0; i < feedArray.length(); i++) {
            JSONObject feedObj = (JSONObject) feedArray.get(i);

            FeedItem item = new FeedItem();
            item.setId(feedObj.getInt("id"));
            item.setName(feedObj.getString("name"));

            // Image might be null sometimes
            String image = feedObj.isNull("image") ? null : feedObj
                    .getString("image");
            item.setImge(image);
            item.setStatus(feedObj.getString("status"));
            item.setProfilePic(feedObj.getString("profilePic"));
            item.setTimeStamp(feedObj.getString("timeStamp"));

            // url might be null sometimes
            String feedUrl = feedObj.isNull("url") ? null : feedObj
                    .getString("url");
            item.setUrl(feedUrl);

            feedItems.add(item);
        }

        // notify data changes to list adapater
        listAdapter.notifyDataSetChanged();
    } catch (JSONException e) {
        e.printStackTrace();
    }
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    getMenuInflater().inflate(R.menu.main, menu);
    return true;
}

}

我怎么能改变android代码才能链接到我的json

1 个答案: