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我是 android 开发的初学者，在搜索了许多网站后，我正在测试基本的 http 客户端服务器应用程序，我得到了下面给出的代码。此代码在本地主机上运行良好，但在我尝试访问远程主机链接时抛出异常是http://gprecelectricus.org/sendMessage.php

java代码是：

package third.example.clientserverapp;

import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;

import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;

import android.R.string;
import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.widget.TextView;

public class MainActivity extends Activity {

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    runOnUiThread(( new Runnable() {

        public void run(){
        HttpClient Client= new DefaultHttpClient();
        HttpGet getData= new HttpGet("http://gprecelectricus.org/sendMessage.php");
        try{
        HttpResponse response= Client.execute(getData);
        if(response!=null)
        {
            String line = "";
            InputStream is= response.getEntity().getContent();
            BufferedReader br = new BufferedReader(new InputStreamReader(is));
            while((line=br.readLine())!=null)
            {
                TextView tv= (TextView) findViewById(R.id.display_msg);
                tv.setText(line);
            }
        }

    }catch(Exception e){

        e.printStackTrace();
        TextView tv= (TextView) findViewById(R.id.display_msg);
        tv.setText("caught exception");
    }
        }
});
}

@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, menu);
    return true;
}

}

日志猫是：

01-26 20:14:20.596: W/System.err(1043): android.os.NetworkOnMainThreadException
01-26 20:14:20.616: W/System.err(1043):     at android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1117)
01-26 20:14:20.616: W/System.err(1043):     at libcore.io.BlockGuardOs.connect(BlockGuardOs.java:84)
01-26 20:14:20.616: W/System.err(1043):     at libcore.io.IoBridge.connectErrno(IoBridge.java:127)
01-26 20:14:20.616: W/System.err(1043):     at libcore.io.IoBridge.connect(IoBridge.java:112)
01-26 20:14:20.630: W/System.err(1043):     at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:192)
01-26 20:14:20.636: W/System.err(1043):     at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:459)
01-26 20:14:20.636: W/System.err(1043):     at java.net.Socket.connect(Socket.java:842)
01-26 20:14:20.636: W/System.err(1043):     at org.apache.http.conn.scheme.PlainSocketFactory.connectSocket(PlainSocketFactory.java:119)
01-26 20:14:20.636: W/System.err(1043):     at org.apache.http.impl.conn.DefaultClientConnectionOperator.openConnection(DefaultClientConnectionOperator.java:144)
01-26 20:14:20.636: W/System.err(1043):     at org.apache.http.impl.conn.AbstractPoolEntry.open(AbstractPoolEntry.java:164)
01-26 20:14:20.647: W/System.err(1043):     at org.apache.http.impl.conn.AbstractPooledConnAdapter.open(AbstractPooledConnAdapter.java:119)
01-26 20:14:20.656: W/System.err(1043):     at org.apache.http.impl.client.DefaultRequestDirector.execute(DefaultRequestDirector.java:360)
01-26 20:14:20.656: W/System.err(1043):     at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:555)
01-26 20:14:20.656: W/System.err(1043):     at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:487)
01-26 20:14:20.656: W/System.err(1043):     at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:465)
01-26 20:14:20.666: W/System.err(1043):     at third.example.clientserverapp.MainActivity$1.run(MainActivity.java:32)
01-26 20:14:20.676: W/System.err(1043):     at android.app.Activity.runOnUiThread(Activity.java:4591)
01-26 20:14:20.676: W/System.err(1043):     at third.example.clientserverapp.MainActivity.onCreate(MainActivity.java:25)
01-26 20:14:20.686: W/System.err(1043):     at android.app.Activity.performCreate(Activity.java:5008)
01-26 20:14:20.686: W/System.err(1043):     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1079)
01-26 20:14:20.686: W/System.err(1043):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2023)
01-26 20:14:20.686: W/System.err(1043):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2084)
01-26 20:14:20.686: W/System.err(1043):     at android.app.ActivityThread.access$600(ActivityThread.java:130)
01-26 20:14:20.686: W/System.err(1043):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1195)
01-26 20:14:20.686: W/System.err(1043):     at android.os.Handler.dispatchMessage(Handler.java:99)
01-26 20:14:20.697: W/System.err(1043):     at android.os.Looper.loop(Looper.java:137)
01-26 20:14:20.706: W/System.err(1043):     at android.app.ActivityThread.main(ActivityThread.java:4745)
01-26 20:14:20.716: W/System.err(1043):     at java.lang.reflect.Method.invokeNative(Native Method)
01-26 20:14:20.716: W/System.err(1043):     at java.lang.reflect.Method.invoke(Method.java:511)
01-26 20:14:20.716: W/System.err(1043):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786)
01-26 20:14:20.726: W/System.err(1043):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
01-26 20:14:20.726: W/System.err(1043):     at dalvik.system.NativeStart.main(Native Method)
01-26 20:14:20.867: W/EGL_emulation(1043): eglSurfaceAttrib not implemented
4

2 回答 2

0

请确保：

  • 在你的 AndroidManifest 中有输入权限 INTERNET

主要活动

@Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        HttpClient client = new  DefaultHttpClient();
        HttpGet request = new HttpGet("http://gprecelectricus.org/sendMessage.php");

        try {
            HttpResponse response = client.execute(request);

            if (response != null) {
                final String result = convertStreamToString(response.getEntity().getContent());
                runOnUiThread(new Runnable() {

                    @Override
                    public void run() {
                        TextView tv= (TextView) findViewById(R.id.display_msg);
                        tv.setText(result);

                    }
                });
            }

        } catch (ClientProtocolException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    private String convertStreamToString(InputStream is) throws IOException {
        String line = "";
        StringBuilder sb = new StringBuilder();
        BufferedReader br = new BufferedReader(new InputStreamReader(is));
        while((line=br.readLine())!=null)
        {
            sb.append(line);
        }
        return sb.toString();
    }
于 2014-01-26T15:07:06.067 回答
0 
 while((line=br.readLine())!=null)
        {
            TextView tv= (TextView) findViewById(R.id.display_msg);
            tv.setText(line);
        }

您无法从另一个线程更改 UI。

使用runOnUIThread

runOnUiThread(new Runnable() {

        @Override
        public void run() {
            // TODO Auto-generated method stub
            while((line=br.readLine())!=null)
            {
                TextView tv= (TextView) findViewById(R.id.display_msg);
                tv.setText(line);
            }
        }
    });
于 2014-01-26T14:18:26.500 回答