Java获取本机外网IP的代码详解编程语言

import java.io.BufferedReader; 
import java.io.InputStreamReader; 
import java.net.URL; 
 
 
public class Listip { 
 
 
public static void main(String[] args) throws Exception { 
System.out.println("本机的外网IP是：" 
+ Listip.getWebIp("http://iframe.ip138.com/ic.asp")); 
} 
 
 
public static String getWebIp(String strUrl) { 
try { 
 
 
URL url = new URL(strUrl); 
BufferedReader br = new BufferedReader(new InputStreamReader(url 
.openStream())); 
String s = ""; 
StringBuffer sb = new StringBuffer(""); 
String webContent = ""; 
while ((s = br.readLine()) != null) { 
sb.append(s + "/r/n"); 
} 
 
 
br.close(); 
webContent = sb.toString(); 
int start = webContent.indexOf("[") + 1; 
int end = webContent.indexOf("]"); 
System.out.println("webContent=" + webContent); 
System.out.println("start=" + start); 
System.out.println("end=" + end); 
if (start < 0 || end < 0) { 
return null; 
} 
webContent = webContent.substring(start, end); 
return webContent; 
 
 
} catch (Exception e) { 
e.printStackTrace(); 
return "error open url:" + strUrl; 
 
 
} 
} 
}