我正在 [博客] 的帮助下：http : //www.androidhive.info/2012/01/android-json-parsing-tutorial/ 来解析 twitter 趋势 JSON 文件，但它会抛出 JSONException。下面是我的活动代码
import java.util.ArrayList;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import android.app.Activity;
import android.os.AsyncTask;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ListView;
public class TweeterJSONReader extends Activity {
Button click;
ListView resultList;
EditText input;
JSONAdapter myAdapter;
ArrayList<SearchResult> mainList;
JSONParser jParser;
private String url ="https://api.twitter.com/1/trends/daily.json";
@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
setLayout();
jParser = new JSONParser();
click.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
new JSONAsync().execute(url);
}
});
}
private class JSONAsync extends AsyncTask<String, Void, JSONObject>
{
JSONArray trends;
@Override
protected JSONObject doInBackground(String... params) {
return jParser.getJSONFromUrl(params[0]);
}
@Override
protected void onPostExecute(JSONObject result) {
try{
trends = result.getJSONArray("trends");
for(int i=0;i<trends.length();i++)
{
JSONObject trend = trends.getJSONObject(i);
String name = trend.getString("name");
String query = trend.getString("query");
SearchResult object = new SearchResult(name, query);
mainList.add(object);
myAdapter = new JSONAdapter(getApplicationContext(),R.layout.search_result_layout,mainList);
resultList.setAdapter(myAdapter);
}
}catch(JSONException ex)
{
ex.printStackTrace();
}
}
}
public void setLayout()
{
mainList = new ArrayList<SearchResult>();
click = (Button) findViewById(R.id.display);
resultList = (ListView) findViewById(R.id.resultList);
input = (EditText) findViewById(R.id.editText1);
}
}
我使用相同的东西通过哈希标签和用户名搜索推文，它们都可以正常工作，但是当我将它用于趋势时，它会抛出 JSONException 以下是我得到的异常
04-04 12:09:25.919: W/ResponseProcessCookies(620): Invalid cookie header: "set-cookie: guest_id=v1%3A136505757287468464; Domain=.twitter.com; Path=/; Expires=Sat, 04-Apr-2015 06:39:32 UTC". Unable to parse expires attribute: Sat, 04-Apr-2015 06:39:32 UTC
04-04 12:09:25.950: W/System.err(620): org.json.JSONException: No value for trends
04-04 12:09:25.950: W/System.err(620): at org.json.JSONObject.get(JSONObject.java:354)
04-04 12:09:25.950: W/System.err(620): at org.json.JSONObject.getJSONArray(JSONObject.java:544)
04-04 12:09:25.969: W/System.err(620): at com.zolipe.twitterapplication.TweeterJSONReader$JSONAsync.onPostExecute(TweeterJSONReader.java:63)
04-04 12:09:25.969: W/System.err(620): at com.zolipe.twitterapplication.TweeterJSONReader$JSONAsync.onPostExecute(TweeterJSONReader.java:1)
04-04 12:09:25.969: W/System.err(620): at android.os.AsyncTask.finish(AsyncTask.java:417)
04-04 12:09:25.969: W/System.err(620): at android.os.AsyncTask.access$300(AsyncTask.java:127)
04-04 12:09:25.969: W/System.err(620): at android.os.AsyncTask$InternalHandler.handleMessage(AsyncTask.java:429)
04-04 12:09:25.969: W/System.err(620): at android.os.Handler.dispatchMessage(Handler.java:99)
04-04 12:09:25.980: W/System.err(620): at android.os.Looper.loop(Looper.java:123)
04-04 12:09:25.992: W/System.err(620): at android.app.ActivityThread.main(ActivityThread.java:3683)
04-04 12:09:25.992: W/System.err(620): at java.lang.reflect.Method.invokeNative(Native Method)
04-04 12:09:25.992: W/System.err(620): at java.lang.reflect.Method.invoke(Method.java:507)
04-04 12:09:25.992: W/System.err(620): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
04-04 12:09:25.999: W/System.err(620): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
04-04 12:09:25.999: W/System.err(620): at dalvik.system.NativeStart.main(Native Method)
04-04 12:09:28.470: D/dalvikvm(121): GC_EXPLICIT freed 126K, 49% free 3050K/5959K, external 3611K/4459K, paused 100ms
请帮我
以下是 JSONParser 的代码
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.UnsupportedEncodingException;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.json.JSONException;
import org.json.JSONObject;
import android.util.Log;
public class JSONParser {
static InputStream is = null;
static JSONObject jObj = null;
static String json = "";
// constructor
public JSONParser() {
}
public JSONObject getJSONFromUrl(String url) {
// Making HTTP request
try {
// defaultHttpClient
DefaultHttpClient httpClient = new DefaultHttpClient();
HttpPost httpPost = new HttpPost(url);
HttpResponse httpResponse = httpClient.execute(httpPost);
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;
}
}