嘗試使Http連接時應用程序強制關閉

這是我的第一個Android應用程序。我張貼我用於HTTP連接的代碼（不是我的，這是來自一個教程網站）。問題是當我按下按鈕來下載文本時，它顯示進度對話框並且app force關閉。我張貼代碼。嘗試使Http連接時應用程序強制關閉

package com.example.httpconnectsample; 

import java.io.IOException; 
import java.io.InputStream; 
import java.io.InputStreamReader; 
import java.net.HttpURLConnection; 
import java.net.MalformedURLException; 
import java.net.URL; 
import java.net.URLConnection; 

import android.app.Activity; 
import android.app.ProgressDialog; 
import android.graphics.Bitmap; 
import android.graphics.BitmapFactory; 
import android.os.Bundle; 
import android.os.Handler; 
import android.os.Message; 
import android.view.View; 
import android.view.View.OnClickListener; 
import android.widget.Button; 
import android.widget.ImageView; 
import android.widget.TextView; 

public class Httpconnectionsample extends Activity { 

private Button getImageButton; 
private Button getTextButton; 
private ProgressDialog progressDialog; 
private Bitmap bitmap = null; 
private String text = null; 

/** Called when the activity is first created. */ 
@Override 
public void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_httpconnectionsample); 

    getImageButton = (Button)findViewById(R.id.Button01); 
    getTextButton = (Button)findViewById(R.id.Button02); 

    getImageButton.setOnClickListener(new OnClickListener() { 

     @Override 
     public void onClick(View v) { 
      downloadImage("http://www.android.com/media/wallpaper /gif/android_logo.gif"); 

     } 
    }); 

    getTextButton.setOnClickListener(new OnClickListener() { 

     @Override 
     public void onClick(View v) { 
      downloadText("http://xyz.com") 
     } 
    }); 
} 


private void downloadImage(String urlStr) { 
    progressDialog = ProgressDialog.show(this, "", "Fetching Image..."); 
    final String url = urlStr; 

    new Thread() { 
     public void run() { 
      InputStream in = null; 
      Message msg = Message.obtain(); 
      msg.what = 1; 
      try { 
       in = openHttpConnection(url); 
       bitmap = BitmapFactory.decodeStream(in); 
       Bundle b = new Bundle(); 
       b.putParcelable("bitmap", bitmap); 
       msg.setData(b); 
       in.close(); 
      } catch (IOException e1) { 
       e1.printStackTrace(); 
      } 
      messageHandler.sendMessage(msg);  

     } 
    }.start(); 

} 

private void downloadText(String urlStr) { 
    progressDialog = ProgressDialog.show(this, "", "Fetching Text..."); 
    final String url = urlStr; 

    new Thread() { 
     public void run() { 
      int BUFFER_SIZE = 2000; 
      InputStream in = null; 
      Message msg = Message.obtain(); 
      msg.what=2; 
      try { 
       in = openHttpConnection(url); 

       InputStreamReader isr = new InputStreamReader(in); 
       int charRead; 
        text = ""; 
        char[] inputBuffer = new char[BUFFER_SIZE]; 

         while ((charRead = isr.read(inputBuffer))>0) 
         {      
          //---convert the chars to a String--- 
          String readString = 
           String.copyValueOf(inputBuffer, 0, charRead);      
          text += readString; 
          inputBuffer = new char[BUFFER_SIZE]; 
         } 
        Bundle b = new Bundle(); 
         b.putString("text", text); 
         msg.setData(b); 
         in.close(); 

      }catch (IOException e) { 
       e.printStackTrace(); 
      } 
      messageHandler.sendMessage(msg); 
     } 
    }.start(); 

} 

private InputStream openHttpConnection(String urlStr) { 
    InputStream in = null; 
    int resCode = -1; 

    try { 
     URL url = new URL(urlStr); 
     URLConnection urlConn = url.openConnection(); 

     if (!(urlConn instanceof HttpURLConnection)) { 
      throw new IOException ("URL is not an Http URL"); 
     } 

     HttpURLConnection httpConn = (HttpURLConnection)urlConn; 
     httpConn.setAllowUserInteraction(false); 
     httpConn.setInstanceFollowRedirects(true); 
     httpConn.setRequestMethod("GET"); 
     httpConn.connect(); 

     resCode = httpConn.getResponseCode();  


     if (resCode == HttpURLConnection.HTTP_OK) { 
      in = httpConn.getInputStream();         
     }  

    } catch (MalformedURLException e) { 
     e.printStackTrace(); 
    } catch (IOException e) { 
     e.printStackTrace(); 
    } 
    return in; 
} 

private Handler messageHandler = new Handler() { 

    public void handleMessage(Message msg) { 
     super.handleMessage(msg); 
     switch (msg.what) { 
       /*case 1: 
      ImageView img = (ImageView) findViewById(R.id.imageview01); 
      img.setImageBitmap((Bitmap)(msg.getData().getParcelable("bitmap"))); 
      break; */ 
     case 2: 
      TextView text = (TextView) findViewById(R.id.textview01); 
      text.setText(msg.getData().getString("text")); 
      break; 
     } 
     progressDialog.dismiss(); 
    } 
}; 
}

下面是我的XML

<?xml version="1.0" encoding="utf-8"?> 
<ScrollView xmlns:android="http://schemas.android.com/apk/res/android" 
    android:id="@+id/scrollView1" 
    android:layout_width="fill_parent" 
    android:layout_height="fill_parent" > 

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" 
xmlns:tools="http://schemas.android.com/tools" 
android:layout_width="fill_parent" 
android:layout_height="fill_parent" > 

<Button 
    android:id="@+id/Button02" 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:layout_marginRight="24dp" 
    android:text="Button" /> 

<Button 
    android:id="@+id/Button01" 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:layout_alignParentRight="true" 
    android:layout_alignParentTop="true" 
    android:layout_marginRight="56dp" 
    android:text="Button" /> 

<TextView 
    android:id="@+id/textview01" 
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content" 
    android:layout_alignParentLeft="true" 
    android:layout_below="@+id/Button02" 
    android:layout_marginTop="39dp" 

    tools:context=".Httpconnectionsample" /> 



</RelativeLayout> 
</ScrollView>

以下是日誌： -

10-26 15:22:43.660: D/ddm-heap(23866): Got feature list request 
    10-26 15:22:48.930: W/System.err(23866): java.net.SocketException: Permission denied  (maybe missing INTERNET permission) 
    10-26 15:22:48.940: W/System.err(23866):  at org.apache.harmony.luni.platform.OSNetworkSystem.createStreamSocketImpl(Native Method) 
    10-26 15:22:48.945: W/System.err(23866):  at org.apache.harmony.luni.platform.OSNetworkSystem.createStreamSocket(OSNetworkSystem.java:187) 
    10-26 15:22:48.945: W/System.err(23866):  at org.apache.harmony.luni.net.PlainSocketImpl.create(PlainSocketImpl.java:266) 
    10-26 15:22:48.950: W/System.err(23866):  at java.net.Socket.checkClosedAndCreate(Socket.java:889) 
    10-26 15:22:48.950: W/System.err(23866):  at java.net.Socket.connect(Socket.java:1036) 
    10-26 15:22:48.950: W/System.err(23866):  at org.apache.harmony.luni.internal.net.www.protocol.http.HttpConnection.<init> (HttpConnection.java:62) 
    10-26 15:22:48.950: W/System.err(23866): at org.apache.harmony.luni.internal.net.www.protocol.http.HttpConnectionManager$ConnectionPool.getHttpConnection(HttpConnectionManager.java:145) 
10-26 15:22:48.950: W/System.err(23866): at org.apache.harmony.luni.internal.net.www.protocol.http.HttpConnectionManager.getConnection(HttpConnectionManager.java:67) 
10-26 15:22:48.960: W/System.err(23866): at org.apache.harmony.luni.internal.net.www.protocol.http.HttpURLConnection.getHTTPConnection(HttpURLConnection.java:821) 
10-26 15:22:48.960: W/System.err(23866): at org.apache.harmony.luni.internal.net.www.protocol.http.HttpURLConnection.connect(HttpURLConnection.java:807) 
10-26 15:22:48.965: W/System.err(23866): at com.example.httpconnectsample.Httpconnectionsample.openHttpConnection(Httpconnectionsample.java:142) 
10-26 15:22:48.965: W/System.err(23866): at com.example.httpconnectsample.Httpconnectionsample.access$3(Httpconnectionsample.java:126) 
10-26 15:22:48.965: W/System.err(23866): at com.example.httpconnectsample.Httpconnectionsample$5.run(Httpconnectionsample.java:97) 
10-26 15:22:48.965: W/dalvikvm(23866): threadid=15: thread exiting with uncaught exception (group=0x4001b180) 
10-26 15:22:48.995: E/AndroidRuntime(23866): Uncaught handler: thread Thread-8 exiting due to uncaught exception 
10-26 15:22:49.090: E/AndroidRuntime(23866): java.lang.NullPointerException 
10-26 15:22:49.090: E/AndroidRuntime(23866): at java.io.Reader.<init>(Reader.java:65) 
10-26 15:22:49.090: E/AndroidRuntime(23866): at java.io.InputStreamReader.<init>(InputStreamReader.java:65) 
10-26 15:22:49.090: E/AndroidRuntime(23866): at com.example.httpconnectsample.Httpconnectionsample$5.run(Httpconnectionsample.java:99) 
10-26 15:22:49.100: I/dalvikvm(23866): threadid=7: reacting to signal 3 
10-26 15:22:49.115: I/dalvikvm(23866): Wrote stack trace to '/data/anr/traces.txt'

我試圖尋找一種修復，但不明白爲什麼會這樣。我只需要下載文本，因此目前我忽略了此代碼的下載圖像部分。此外，我在清單中添加了使用權限android：name =「android.permission.INTERNET」，但仍然顯示權限被拒絕。我會很感激任何幫助。

來源

2012-10-26 user1581539

發表您的AndroidManifest.xml文件 –

將INTERNET權限添加到您的清單文件。

你要加入這一行：

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

在AndroidManifest.xml中的應用程序標記之外如下圖所示

<?xml version="1.0" encoding="utf-8"?> 
<manifest xmlns:android="http://schemas.android.com/apk/res/android" 
package="com.demo" 
android:versionCode="1" 
android:versionName="1.0" > 

<uses-sdk android:minSdkVersion="15" /> 

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

<application> 
    //your stuffs 
</application> 

</manifest>

來源

2012-10-26 10:19:09

他已經提到權限添加到清單 –

可能他沒有在適當的位置添加權限。 –

感謝您回覆的人，但似乎我已經浪費了幾個小時的事情。我在「uses-sdk」標籤內寫了這個「使用許可標籤」。我現在已經從那裏刪除了互聯網許可標籤，現在代碼正在工作。謝謝你的回覆。 :) – user1581539

嘗試使Http連接時應用程序強制關閉

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