Question

如何解决android使用HttpUrlConnection抛出异常

Answer 1

　在Android的Activity中使用HttpURLConnection连接到服务端时抛出异常，Access denied。第一个想到是权限问题。然后就尝试将INTERNET权限加上：在Manifest中加上：
　　
　　<uses-permission android:name="android.permission.INTERNET" />

还是抛异常！看异常信息，和StrictMode有关，想到和Android版本有关，然后在Activity中加上如下代码，问题解决：
　　
　　
　　StrictMode.setThreadPolicy(new StrictMode.ThreadPolicy.Builder().detectDiskReads().detectDiskWrites().detectNetwork().penaltyLog().build());

完整代码：
　　
　　
　　package com.example.quhao_test;

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

import android.annotation.TargetApi;
import android.app.Activity;
import android.os.Build;
import android.os.Bundle;
import android.os.StrictMode;
import android.view.Menu;
import android.widget.TextView;

public class MainActivity extends Activity {

@TargetApi(Build.VERSION_CODES.GINGERBREAD)
@Override
protected void onCreate(Bundle savedInstanceState) {

System.out.println("xxxxxxxxxxxxxxx");

super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);

String strUrl = "http://146.11.24.100:9081/testcontroller/test1?arg=2222";
StrictMode.setThreadPolicy(new StrictMode.ThreadPolicy.Builder().detectDiskReads().detectDiskWrites().detectNetwork().penaltyLog().build());
URL url = null;
try {
url = new URL(strUrl);
System.out.println(url.getPort());
HttpURLConnection urlConn = (HttpURLConnection) url.openConnection();
InputStreamReader in = new InputStreamReader(urlConn.getInputStream());
BufferedReader br = new BufferedReader(in);
String result = "";
String readerLine = null;
while((readerLine=br.readLine())!=null){
result += readerLine;
}
in.close();
urlConn.disconnect();

System.out.println("r:"+result);
TextView textView = (TextView)this.findViewById(R.id.result);
textView.setText(result);
} catch (MalformedURLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}

}

@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;
}

}