Java 获取本机的ip和主机名

import java.io.BufferedReader;

import java.io.IOException;

import java.io.InputStreamReader;

import java.net.HttpURLConnection;

import java.net.InetAddress;

import java.net.MalformedURLException;

import java.net.URL;

import java.net.UnknownHostException;

public class LoaclHostUtils {

/**

* 获取本机内网IP

* @return

*/

public static String getLocalHostIP(){

return getLocalHost().getHostAddress();

}

/**

* 获取本机当前用户名

* @return

*/

public static String getLocalHostName(){

return getLocalHost().getHostName();

}

public static InetAddress getLocalHost(){

InetAddress netAddress=null;

try {

netAddress=InetAddress.getLocalHost();

} catch (UnknownHostException e) {

e.printStackTrace();

}

return netAddress;

}

/**

* 获取外网IP

* 采用访问http://iframe.ip138.com/ic.asp来获取外网IP

* @return

*/

public static String getOuterNetIP(){

String checkURL="http://iframe.ip138.com/ic.asp";

HttpURLConnection conn=null;

String outerIPStr="";

try {

URL url=new URL(checkURL);

conn=(HttpURLConnection) url.openConnection();

conn.setInstanceFollowRedirects(false);

conn.connect();

BufferedReader reader=new BufferedReader(new InputStreamReader(conn.getInputStream()));

while((outerIPStr=reader.readLine()) != null){

if(outerIPStr.indexOf("[") > 0){

outerIPStr=outerIPStr.substring(outerIPStr.indexOf("[")+1,outerIPStr.indexOf("]"));

break;

}

}

} catch (MalformedURLException e) {

e.printStackTrace();

} catch (IOException e) {

e.printStackTrace();

}

return outerIPStr;

}

}

其中System.getProperties中包含很多的信息，包括：

Java中System.getProperty的使用