package net.test;
import java.net.*;
import java.io.*;
public class JLookup {
public static void main(String args[]) {
if(args.length > 0) {
//如果存在命令行参数，则解析每个参数
for(int i=0; i<args.length; i++) {
lookup(args[i]);
System.out.println("");
}
}
else {
//等待命令行输入，Q用来从程序退出
System.out.println("Enter a hostname or IP.(\"Q\" to Quit)");
BufferedReader input = new BufferedReader(
new InputStreamReader(System.in));
while(true) {
try {
String prompt = "JLookup>";
System.out.print(prompt);
//读取一行输入
String line = input.readLine().trim();
if(line.equalsIgnoreCase("Q")) {
input.close();
break;
}
//IP地址和主机名相互解析
lookup(line);
}catch(IOException ioe) {
ioe.printStackTrace();
}
}
}
}
private static void lookup(String host) {
InetAddress hostInetAddr[];
try {
//创建InetAddress对象
hostInetAddr = InetAddress.getAllByName(host);
}catch(UnknownHostException e) {
System.out.println("Unknown Host:" + host);
return;
}
if(isHostname(host)) {
//如果是主机名，则输出IP地址
for(int i=0; i<hostInetAddr.length; i++) {
System.out.println(hostInetAddr[i].getHostAddress());
}
}
else {
//如果是IP地址，则输出主机名
for(int i=0; i<hostInetAddr.length; i++) {
System.out.println(hostInetAddr[i].getHostName());
}
}
}
剩余8页未读，继续阅读
资源评论
