java取ip地址
① java中如何获取到本机的外网ip地址
java获取本机的外网ip示例：
import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
/**
* 获取本机外网IP地址
* 思想是访问网站http://checkip.dyndns.org/，得到返回的文本后解析出本机在外网的IP地址
* @author pieryon
*
*/
public class ExternalIpAddressFetcher {
// 外网IP提供者的网址
private String externalIpProviderUrl;
// 本机外网IP地址
private String myExternalIpAddress;
public ExternalIpAddressFetcher(String externalIpProviderUrl) {
this.externalIpProviderUrl = externalIpProviderUrl;
String returnedhtml = fetchExternalIpProviderHTML(externalIpProviderUrl);
parse(returnedhtml);
}
/**
* 从外网提供者处获得包含本机外网地址的字符串
* 从http://checkip.dyndns.org返回的字符串如下
* <html><head><title>Current IP Check</title></head><body>Current IP Address: 123.147.226.222</body></html>
* @param externalIpProviderUrl
* @return
*/
private String fetchExternalIpProviderHTML(String externalIpProviderUrl) {
// 输入流
InputStream in = null;
// 到外网提供者的Http连接
HttpURLConnection httpConn = null;
try {
// 打开连接
URL url = new URL(externalIpProviderUrl);
httpConn = (HttpURLConnection) url.openConnection();
// 连接设置
HttpURLConnection.setFollowRedirects(true);
httpConn.setRequestMethod("GET");
httpConn.setRequestProperty("User-Agent",
"Mozilla/4.0 (compatible; MSIE 6.0; Windows 2000)");
// 获取连接的输入流
in = httpConn.getInputStream();
byte[] bytes=new byte[1024];// 此大小可根据实际情况调整
// 读取到数组中
int offset = 0;
int numRead = 0;
while (offset < bytes.length
&& (numRead=in.read(bytes, offset, bytes.length-offset)) >= 0) {
offset += numRead;
}
// 将字节转化为为UTF-8的字符串
String receivedString=new String(bytes,"UTF-8");
// 返回
return receivedString;
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
in.close();
httpConn.disconnect();
} catch (Exception ex) {
ex.printStackTrace();
}
}
// 出现异常则返回空
return null;
}
/**
* 使用正则表达式解析返回的HTML文本,得到本机外网地址
* @param html
*/
private void parse(String html){
Pattern pattern=Pattern.compile("(\\d{1,3})[.](\\d{1,3})[.](\\d{1,3})[.](\\d{1,3})", Pattern.CASE_INSENSITIVE);
Matcher matcher=pattern.matcher(html);
while(matcher.find()){
myExternalIpAddress=matcher.group(0);
}
}
/**
* 得到本机外网地址,得不到则为空
* @return
*/
public String getMyExternalIpAddress() {
return myExternalIpAddress;
}
public static void main(String[] args){
ExternalIpAddressFetcher fetcher=new ExternalIpAddressFetcher("http://checkip.dyndns.org/");
System.out.println(fetcher.getMyExternalIpAddress());
}
}
② java如何查询本机ip地址和mac地址
Java中可以使用程序来获取本地ip地址和mac地址，使用InetAddress这个工具类，示例如下：
importjava.net.*;
publicclassNetInfo{
publicstaticvoidmain(String[]args){
newNetInfo().say();
}
publicvoidsay(){
try{
InetAddressi=InetAddress.getLocalHost();
System.out.println(i);//计算机名称和IP
System.out.println(i.getHostName());//名称
System.out.println(i.getHostAddress());//只获得IP
}
catch(Exceptione){e.printStackTrace();}
}
}
也可以通过命令行窗口来查看本地ip和mac地址，输入命令：ipconfig。
③ java中获取本地IP地址
方法如下：
方法一，使用CMD命令：
public static String getLocalIPForCMD(){
StringBuilder sb = new StringBuilder();
String command = "cmd.exe /c ipconfig | findstr IPv4";
try {
Process p = Runtime.getRuntime().exec(command);
BufferedReader br = new BufferedReader(new InputStreamReader(p.getInputStream()));
String line = null;
while((line = br.readLine()) != null){
line = line.substring(line.lastIndexOf(":")+2,line.length());
sb.append(line);
}
br.close();
p.destroy();
} catch (IOException e) {
e.printStackTrace();
}
return sb.toString();
}
方法二，使用Java方法：
public static String getLocalIPForJava(){
StringBuilder sb = new StringBuilder();
try {
Enumeration<NetworkInterface> en = NetworkInterface.getNetworkInterfaces();
while (en.hasMoreElements()) {
NetworkInterface intf = (NetworkInterface) en.nextElement();
Enumeration<InetAddress> enumIpAddr = intf.getInetAddresses();
while (enumIpAddr.hasMoreElements()) {
InetAddress inetAddress = (InetAddress) enumIpAddr.nextElement();
if (!inetAddress.isLoopbackAddress() && !inetAddress.isLinkLocalAddress()
&& inetAddress.isSiteLocalAddress()) {
sb.append(inetAddress.getHostAddress().toString()+"\n");
}
}
}
} catch (SocketException e) { }
return sb.toString();
}