我想在我的Android应用中从Twitter获取Feed。为了做到这一点，我使用了一些示例代码，现在我无法启动应用程序。这是代码：
import org.apache.http.client.HttpClient;
import org.apache.http.client.ResponseHandler;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.BasicResponseHandler;
import org.apache.http.impl.client.DefaultHttpClient;
import org.json.simple.JSONArray;
import org.json.simple.JSONObject;
import org.json.simple.JSONValue;
import org.json.simple.parser.JSONParser;
import android.app.Activity;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.net.Uri;
import android.os.Bundle;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.ImageView;
import android.widget.ListView;
import android.widget.TextView;
public class Twitter extends Activity {
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.twitter_layout);
ArrayList<Tweet> tweets = getTweets("android", 1);
ListView listView = (ListView) findViewById(R.id.ListViewId);
listView.setAdapter(new UserItemAdapter(this, R.layout.listitem, tweets));
}
public class UserItemAdapter extends ArrayAdapter<Tweet> {
private ArrayList<Tweet> tweets;
public UserItemAdapter(Context context, int textViewResourceId, ArrayList<Tweet> tweets) {
super(context, textViewResourceId, tweets);
this.tweets = tweets;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
View v = convertView;
if (v == null) {
LayoutInflater vi = (LayoutInflater)getSystemService(Context.LAYOUT_INFLATER_SERVICE);
v = vi.inflate(R.layout.listitem, null);
}
Tweet tweet = tweets.get(position);
if (tweet != null) {
TextView username = (TextView) v.findViewById(R.id.username);
TextView message = (TextView) v.findViewById(R.id.message);
ImageView image = (ImageView) v.findViewById(R.id.avatar);
if (username != null) {
username.setText(tweet.username);
}
if(message != null) {
message.setText(tweet.message);
}
if(image != null) {
image.setImageBitmap(getBitmap(tweet.image_url));
}
}
return v;
}
}
public Bitmap getBitmap(String bitmapUrl) {
try {
URL url = new URL(bitmapUrl);
return BitmapFactory.decodeStream(url.openConnection() .getInputStream());
}
catch(Exception ex) {return null;}
}
public ArrayList<Tweet> getTweets(String searchTerm, int page) {
String searchUrl = "http://search.twitter.com/search.json?q=@"
+ searchTerm + "&rpp=100&page=" + page;
ArrayList<Tweet> tweets = new ArrayList<Tweet>();
HttpClient client = new DefaultHttpClient();
HttpGet get = new HttpGet(searchUrl);
ResponseHandler<String> responseHandler = new BasicResponseHandler();
String responseBody = null;
try{
responseBody = client.execute(get, responseHandler);
}catch(Exception ex) {
ex.printStackTrace();
}
JSONObject jsonObject = null;
/* */
JSONParser pars=new JSONParser();
/* */
try {
Object obj = pars.parse(responseBody);
jsonObject=(JSONObject)obj;
}catch(Exception ex){
Log.v("TEST","Exception: " + ex.getMessage());
}
JSONArray arr = null;
try {
Object j = jsonObject.get("results");
arr = (JSONArray)j;
}catch(Exception ex){
Log.v("TEST","Exception: " + ex.getMessage());
}
for(Object t : arr) {
Tweet tweet = new Tweet(
((JSONObject)t).get("from_user").toString(),
((JSONObject)t).get("text").toString(),
((JSONObject)t).get("profile_image_url").toString()
);
tweets.add(tweet);
}
return tweets;
}
public class Tweet {
public String username;
public String message;
public String image_url;
public Tweet(String username, String message, String url) {
this.username = username;
this.message = message;
this.image_url = url;
}
}
}
这是我的LogCat：
05-23 11:34:16.443: E/AndroidRuntime(25616): FATAL EXCEPTION: main
05-23 11:34:16.443: E/AndroidRuntime(25616): java.lang.NoClassDefFoundError: org.json.simple.parser.JSONParser
05-23 11:34:16.443: E/AndroidRuntime(25616): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
05-23 11:34:16.443: E/AndroidRuntime(25616): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2627)
05-23 11:34:16.443: E/AndroidRuntime(25616): at android.app.ActivityThread.startActivityNow(ActivityThread.java:2503)
05-23 11:34:16.443: E/AndroidRuntime(25616): at android.app.LocalActivityManager.moveToState(LocalActivityManager.java:127)
05-23 11:34:16.443: E/AndroidRuntime(25616): at android.app.LocalActivityManager.startActivity(LocalActivityManager.java:339)
05-23 11:34:16.443: E/AndroidRuntime(25616): at android.widget.TabHost$IntentContentStrategy.getContentView(TabHost.java:673)
05-23 11:34:16.443: E/AndroidRuntime(25616): at android.widget.TabHost.setCurrentTab(TabHost.java:345)
05-23 11:34:16.443: E/AndroidRuntime(25616): at android.widget.TabHost$2.onTabSelectionChanged(TabHost.java:138)
05-23 11:34:16.443: E/AndroidRuntime(25616): at android.widget.TabWidget$TabClickListener.onClick(TabWidget.java:453)
05-23 11:34:16.443: E/AndroidRuntime(25616): at android.view.View.performClick(View.java:2408)
05-23 11:34:16.443: E/AndroidRuntime(25616): at android.view.View$PerformClick.run(View.java:8816)
05-23 11:34:16.443: E/AndroidRuntime(25616): at android.os.Handler.handleCallback(Handler.java:587)
05-23 11:34:16.443: E/AndroidRuntime(25616): at android.os.Handler.dispatchMessage(Handler.java:92)
05-23 11:34:16.443: E/AndroidRuntime(25616): at android.os.Looper.loop(Looper.java:123)
05-23 11:34:16.443: E/AndroidRuntime(25616): at android.app.ActivityThread.main(ActivityThread.java:4627)
05-23 11:34:16.443: E/AndroidRuntime(25616): at java.lang.reflect.Method.invokeNative(Native Method)
05-23 11:34:16.443: E/AndroidRuntime(25616): at java.lang.reflect.Method.invoke(Method.java:521)
05-23 11:34:16.443: E/AndroidRuntime(25616): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:878)
05-23 11:34:16.443: E/AndroidRuntime(25616): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:636)
05-23 11:34:16.443: E/AndroidRuntime(25616): at dalvik.system.NativeStart.main(Native Method)
答案 0 :(得分：3)
您需要在项目的Lib或Libs目录中拥有json-simple jar。您可能目前已将其设置为可以将jar用于构建，但不包含在构建的应用程序中。
答案 1 :(得分：2)
你应该导入，
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
并使用
JSONArray aryJSONStrings = new JSONArray("your json string");
for (int i=0; i<aryJSONStrings.length(); i++) {
NewsItemId = aryJSONStrings.getJSONObject(i).getString("your_attribute_name");
}