获取外网ip地址java

㈠ java获取外网IP

请参考以下代码，可以获得任意给定网卡的ip地址：

import java.net.InetAddress;
import java.net.NetworkInterface;
import java.net.SocketException;
import java.util.Enumeration;

public class InternetTest {

public static void main(String[] args) {
String netCard = "lo";
try {
Enumeration<NetworkInterface> netInterfaces = NetworkInterface
.getNetworkInterfaces();
if (netInterfaces.hasMoreElements()) {
NetworkInterface netInterface = netInterfaces.nextElement();
if (netCard.equals(netInterface.getName())) {
// 子接口，linux下会取到父接口？？
Enumeration<NetworkInterface> subnetInterfaces = netInterface
.getSubInterfaces();
while (subnetInterfaces.hasMoreElements()) {
NetworkInterface subnetInterface = subnetInterfaces
.nextElement();
System.out.println(subnetInterface.getName());
Enumeration<InetAddress> subaddresses = netInterface
.getInetAddresses();
while (subaddresses.hasMoreElements()) {
InetAddress subaddress = subaddresses.nextElement();
System.out.println(subaddress.getHostAddress());
}
}
// 打印接口下所有IP
System.out.println(netInterface.getName());
Enumeration<InetAddress> addresses = netInterface
.getInetAddresses();
while (addresses.hasMoreElements()) {
InetAddress address = addresses.nextElement();
System.out.println(address.getHostAddress());
}
}
}
} catch (SocketException e) {
e.printStackTrace();
}
}
}

㈡ 局域网中的电脑如何用java代码取得出口IP

public class GetRealIp {
public static void main(String[] args) throws SocketException {
System.out.println(GetRealIp.getRealIp());
}
public static String getRealIp() throws SocketException {
String localip = null;// 本地IP，如果没有配置外网IP则返回它
String netip = null;// 外网IP
Enumeration<NetworkInterface> netInterfaces =
NetworkInterface.getNetworkInterfaces();
InetAddress ip = null;
boolean finded = false;// 是否找到外网IP
while (netInterfaces.hasMoreElements() && !finded) {
NetworkInterface ni = netInterfaces.nextElement();
Enumeration<InetAddress> address = ni.getInetAddresses();
while (address.hasMoreElements()) {
ip = address.nextElement();
if (!ip.isSiteLocalAddress()
&& !ip.isLoopbackAddress()
&& ip.getHostAddress().indexOf(":") == -1) {// 外网IP
netip = ip.getHostAddress();
finded = true;
break;
} else if (ip.isSiteLocalAddress()
&& !ip.isLoopbackAddress()
&& ip.getHostAddress().indexOf(":") == -1) {// 内网IP
localip = ip.getHostAddress();
}
}
}
if (netip != null && !"".equals(netip)) {
return netip;
} else {
return localip;
}
}
}
自己写了一个帮你实现，希望对你有帮助

㈢ java如何获取公网ip，有通过路由

如果要通过路由器，不同的路由器的获取方法不一样。通用的做法是通过 HttpClient 在网络上搜索关键字 ip, 然后提取出公网ip。

importjava.io.BufferedReader;
importjava.io.IOException;
importjava.io.InputStream;
importjava.io.InputStreamReader;
importjava.net.URL;
importjava.net.URLConnection;
importjava.util.regex.Matcher;
importjava.util.regex.Pattern;

publicclassApp{

//获取网页源码
staticStringhttpGet(Stringurl){

StringBufferbuffer=newStringBuffer();

try{

URLConnectionconn=newURL(url).openConnection();

conn.addRequestProperty("User-Agent","Mozilla/5.0(WindowsNT10.0;Win64;x64)AppleWebKit/537.36(KHTML,likeGecko)Chrome/67.0.3396.99Safari/537.36");

try(InputStreaminputStream=conn.getInputStream();
InputStreamReaderstreamReader=newInputStreamReader(inputStream);
BufferedReaderreader=newBufferedReader(streamReader);){

Stringline=null;

while((line=reader.readLine())!=null){
buffer.append(line).append(System.lineSeparator());
}
}

}catch(IOExceptione){
e.printStackTrace();
}

returnbuffer.toString();
}

publicstaticvoidmain(String[]args){

Stringhtml=httpGet("https://www..com/s?wd=ip");

//提出IP

Patternpattern=Pattern.compile("<span\sclass="c-gap-right">本机IP:&nbsp;([^<]+)</span>");

Matchermatcher=pattern.matcher(html);

if(matcher.find()){

Stringip=matcher.group(1);

System.out.println(ip);
}

}
}

㈣ 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());
}
}