在httpURL中学习android..getting IO异常

Question

我正在学习android，并且陷入IO异常yy块中。 有人能帮我吗。 下面是我的代码

package com.example.blogreader;

import java.io.IOException;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;

import android.app.ListActivity;
import android.os.AsyncTask;
import android.os.Bundle;
import android.util.Log;
import android.view.Menu;

public class MainListActivity extends ListActivity {
    protected String[] mHospitals;
    public static final int NUMBER_OF_HOSPITALS = 20;
    public static final String TAG = MainListActivity.class.getSimpleName();

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main_list);
//      
//      Resources resource = getResources();
//      mHospitals = resource.getStringArray(R.array.hospital_names);
//      
//      ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, mHospitals);
//      setListAdapter(adapter);
        //Toast.makeText(this, getString(R.string.no_hospitals_fond),Toast.LENGTH_LONG).show();
        GetBlogPostsTask getBlogPostsTask = new GetBlogPostsTask();
        getBlogPostsTask.execute();

    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main_list, menu);
        return true;
    }

    private class GetBlogPostsTask extends AsyncTask<Object, Void, String> {


        protected String doInBackground(Object... arg0) {
            int reponseCode = -1;

            try {

                URL hospitalFeedUrl = new URL("http://blog.teamtreehouse.com/api/get_recent_summary/?count=" + NUMBER_OF_HOSPITALS);
                HttpURLConnection connection = (HttpURLConnection) hospitalFeedUrl.openConnection();
                connection.connect();
                reponseCode = connection.getResponseCode();
                Log.i(TAG, "Code " + reponseCode);
            } 
            catch (MalformedURLException e) {
                Log.e(TAG, "exception caught xx :", e); 
            }
            catch (IOException e) {
                Log.e(TAG, "exception IO caught yy : ", e); 
            }
            catch(Exception e){
                Log.e(TAG, "General exception zz :", e);
            }

            return "Code "+ reponseCode;    
        }

    }

}

Answer 1

如果没有logcat，这是一个很疯狂的猜测，但是您可能忘记了将INTERNET权限授予您的AndroidManifest.xml吗？

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