可以使用 InetAddress.getLocalHost()，代码如下：
import java.net.*public class App {
public static void main(String[] args) throws UnknownHostException {
InetAddress local = InetAddress.getLocalHost()
System.out.println("计算机名：" + local.getHostName())
System.out.println("IP：" + local.getHostAddress())
}
}
import java.net.*public class Test6 {
public static void main(String[] args) {
// TODO Auto-generated method stub
InetAddress ia=null
try {
ia=ia.getLocalHost()
String localname=ia.getHostName()
String localip=ia.getHostAddress()
System.out.println("本机名称是："+ localname)
System.out.println("本机的ip是 ："+localip)
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace()
}
}
}
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 (compatibleMSIE 6.0Windows 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())
}
}
