HttpClient的java.net.UnknownHostException

[java]代码库

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

import org.apache.http.HttpEntity;
import org.apache.http.HttpHost;
import org.apache.http.HttpResponse;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.conn.params.ConnRouteParams;
import org.apache.http.impl.client.DefaultHttpClient;


public class Test {
 public static void main(String[] args) {
  String str = "";
  HttpClient client = new DefaultHttpClient();
  HttpGet get = new HttpGet("http://www.baidu.com/");
  try {
   HttpResponse response = client.execute(get);
   HttpEntity entity = response.getEntity();
   BufferedReader reader = new BufferedReader(
     new InputStreamReader(
       entity.getContent()));
   while((str = reader.readLine()) != null) {
    System.out.println(str);
   }
  } catch (ClientProtocolException e) {
   e.printStackTrace();
  } catch (IOException e) {
   e.printStackTrace();
  }
 }
}//源代码片段来自云代码http://yuncode.net


java.net.UnknownHostException: www.baidu.com
 at java.net.Inet4AddressImpl.lookupAllHostAddr(Native Method)
 at java.net.InetAddress$1.lookupAllHostAddr(InetAddress.java:850)
 at java.net.InetAddress.getAddressFromNameService(InetAddress.java:1201)
 at java.net.InetAddress.getAllByName0(InetAddress.java:1154)
 at java.net.InetAddress.getAllByName(InetAddress.java:1084)
 at java.net.InetAddress.getAllByName(InetAddress.java:1020)
 at org.apache.http.impl.conn.DefaultClientConnectionOperator.resolveHostname(DefaultClientConnectionOperator.java:242)
 at org.apache.http.impl.conn.DefaultClientConnectionOperator.openConnection(DefaultClientConnectionOperator.java:130)
 at org.apache.http.impl.conn.AbstractPoolEntry.open(AbstractPoolEntry.java:150)
 at org.apache.http.impl.conn.AbstractPooledConnAdapter.open(AbstractPooledConnAdapter.java:121)
 at org.apache.http.impl.client.DefaultRequestDirector.tryConnect(DefaultRequestDirector.java:575)
 at org.apache.http.impl.client.DefaultRequestDirector.execute(DefaultRequestDirector.java:425)
 at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:820)
 at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:754)
 at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:732)
 at Test.main(Test.java:22)//源代码片段来自云代码http://yuncode.net