Java网络程序设计 精简启蒙版

getLocalHost()                 返回本地主机的InetAddress对象                 InetAddress类型
getByName(String host)         获取指定主机名称的IP地址                       InetAddress类型
getHostName()                  获取此主机名                                 String
getHostAddress()               获取主机IP地址                               String
isReachable(int timeout)       在timeout指定的毫秒时间内，测试IP地址是否可达    Boolean

package bigjunoba.bjtu.iptoname;

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

public class IPToName {
    public static void main(String[] args) {
        String IP = null;
        for (int i = 1; i <= 150; i++) {
            IP = "192.168.131." + i;                        //生成IP字符串
            try {
                InetAddress host;
                host = InetAddress.getByName(IP);            //获取IP封装对象
                if (host.isReachable(1000)) {               //用1秒的时间测试IP地址是否可达
                    String hostName = host.getHostName(); 
                    System.out.println("IP地址" + IP + "的主机名称是：" + hostName);
                }
            } catch (UnknownHostException e) {              //捕获未知主机异常
                e.printStackTrace();
            } catch (IOException e) {                       //捕获输入输出异常
                e.printStackTrace();
            }
        }
        System.out.println("搜索完毕！");
    }
}

IP地址192.168.131.1的主机名称是：BigjunOba
搜索完毕！

            try {
                ServerSocket server = new ServerSocket();
            } catch (IOException e) {
                e.printStackTrace();
            }

            try {
                ServerSocket server = new ServerSocket(9527);
            } catch (IOException e) {
                e.printStackTrace();
            }
        }

            try {
                ServerSocket server = new ServerSocket(9527, 300);
            } catch (IOException e) {
                e.printStackTrace();
            }
        }

            try {
                ServerSocket server = new ServerSocket(9527, 300);
            } catch (IOException e) {
                e.printStackTrace();
            }
        }