Java6学习笔记62——显示IP

最新推荐文章于 2025-12-11 23:29:47 发布

最新推荐文章于 2025-12-11 23:29:47 发布 · 89 阅读

文章标签：

#Java #.net

本文介绍了一个简单的Java程序，该程序能够获取并显示不同类型的IP地址，包括通过域名获取的IP地址、本地主机的IP地址以及特定IPv4地址。程序使用了InetAddress类的相关方法，并展示了如何检查IP地址是否为回环地址以及是否可达。

import java.net.InetAddress;
import java.net.UnknownHostException;
import java.io.IOException;

public class ShowIP {
public static void main(String arg[]) {
InetAddress address;

try {
address = InetAddress.getByName("g.cn");
showAddress(address);
address = InetAddress.getLocalHost();
showAddress(address);
byte a[] = { 127,0,0,1 };
address = InetAddress.getByAddress(a);
showAddress(address);
} catch(UnknownHostException e) {
System.out.println(e);
}

}
static void showAddress(InetAddress address) {
byte a[] = address.getAddress();
System.out.println(address.getHostName() +
": " + (a[0] & 0xFF) + "." + (a[1] & 0xFF) +
"." + (a[2] & 0xFF) + "." + (a[3] & 0xFF));//与0xFF做与运算，把符号位剔除
if(address.isLoopbackAddress())
System.out.println(" (the loopback address)");
try {
if(address.isReachable(30000))
System.out.println(" (is reachable)");
} catch(IOException e) {
}
}
}