学步园

ctrl+o 输网址 屏蔽自动保存网址
hosts 文件实现ip地址映射
ping 十进制ip

import java.text.DecimalFormat;<br /> import java.util.Scanner;<br /> import java.util.regex.Matcher;<br /> import java.util.regex.Pattern;<br /> public class Main {<br /> public static void main(String[] args) {<br /> //System.out.println("Hello World!");<br /> Scanner in = new Scanner(System.in);<br /> String ip = in.next();<br /> Pattern p = Pattern<br /> .compile("((2[0-4]//d|25[0-5]|[01]?//d//d?)//.){3}(2[0-4]//d|25[0-5]|[01]?//d//d?)");<br /> Matcher m = p.matcher(ip);</p> <p> if(true == m.matches()) {<br /> String[] strs = ip.split("//.");//.是元字符<br /> double result = 0;<br /> int len = strs.length;<br /> for(int i = 0; i<len; ++i) {<br /> //System.out.println(Integer.parseInt(strs[i])*Math.pow(256, 3-i));<br /> result += Integer.parseInt(strs[i])*Math.pow(256, 3-i);<br /> }<br /> DecimalFormat format=new DecimalFormat( "0");<br /> String resultStr = format.format(result);<br /> System.out.println(ip + "->" + resultStr);<br /> } else<br /> System.out.println("Invalid IP!");<br /> }<br /> }<br />
文件->另存为  保存类型 .mht