尝试建立 Http 连接时应用程序强制关闭
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【中文标题】尝试建立 Http 连接时应用程序强制关闭【英文标题】：App force closing when trying to make Http connection 【发布时间】：2012-10-16 14:26:52 【问题描述】：这是我的第一个安卓应用。我正在发布我用于 HTTP 连接的代码（不是我的，这是来自一个教程站点）。问题是当我按下下载文本的按钮时，它会显示进度对话框并且应用程序强制关闭。我正在发布代码。
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();
;
以下是我的 XML
<?xml version="1.0" encoding="utf-8"?>
<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/scrollView1"
android:layout_
android:layout_ >
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_
android:layout_ >
<Button
android:id="@+id/Button02"
android:layout_
android:layout_
android:layout_marginRight="24dp"
android:text="Button" />
<Button
android:id="@+id/Button01"
android:layout_
android:layout_
android:layout_alignParentRight="true"
android:layout_alignParentTop="true"
android:layout_marginRight="56dp"
android:text="Button" />
<TextView
android:id="@+id/textview01"
android:layout_
android:layout_
android:layout_alignParentLeft="true"
android:layout_below="@+id/Button02"
android:layout_marginTop="39dp"
tools:context=".Httpconnectionsample" />
</RelativeLayout>
</ScrollView>
以下是日志：-
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'
我尝试寻找修复程序，但不明白为什么会发生这种情况。我只需要下载文本，所以目前我忽略了此代码的下载图像部分。另外，我补充说 使用权限 android:name="android.permission.INTERNET" 就在清单上方，但仍然显示权限被拒绝。 如有任何帮助，我将不胜感激。
【问题讨论】：
发布你的 androidmanifest.xml 文件 【参考方案1】：将INTERNET 权限添加到您的清单文件。
你必须添加这一行：
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
<uses-permission android:name="android.permission.INTERNET" />
在你的 AndroidManifest.xml 中的应用标签之外，如下所示
<?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>
【讨论】：
他已经提到manifest中添加了权限 可能他没有在适当的位置添加权限。 感谢大家的回复，但似乎我在一件小事上浪费了几个小时。我在“uses-sdk”标签中写了这个“使用权限标签”。我现在已经从那里删除了互联网许可标签，现在代码正在运行。非常感谢您的回复。 :)以上是关于尝试建立 Http 连接时应用程序强制关闭的主要内容，如果未能解决你的问题，请参考以下文章