Home > Java > JavaBase > body text

Java determines whether ip

Release: 2019-11-20 13:47:36
Original
2052 people have browsed it

Java determines whether ip

java使用正则表达式判断是否是IP:

package com.you.dao;  
  
import java.util.regex.Matcher;  
import java.util.regex.Pattern;  
  
/** 
 * @类名:IpAddress 
 * @描述:用正则表达式判断是否为IP 
 */  
public class IpAddress   
{  
    public static class IpAdd  
    {  
        public boolean isIP(String addr)  
        {  
            if(addr.length() < 7 || addr.length() > 15 || "".equals(addr))  
            {  
                return false;  
            }  
            /** 
             * 判断IP格式和范围 
             */  
            String rexp = "([1-9]|[1-9]\\d|1\\d{2}|2[0-4]\\d|25[0-5])(\\.(\\d|[1-9]\\d|1\\d{2}|2[0-4]\\d|25[0-5])){3}";  
              
            Pattern pat = Pattern.compile(rexp);    
              
            Matcher mat = pat.matcher(addr);    
              
            boolean ipAddress = mat.find();  
  
            return ipAddress;  
        }  
    }  
  
    /** 
     * @Title : main 
     * @Type : IpAddress 
     * @date : 2014年3月4日 下午10:55:06 
     * @Description : IP可能的范围是0-255.0-255.0-255.0-255 
     * @param args 
     */  
    public static void main(String[] args)   
    {  
        /** 
         * 符合IP地址的范围 
         */  
         String oneAddress = "10.127.30.45";  
         /** 
         * 符合IP地址的长度范围但是不符合格式 
         */  
         String twoAddress = "127.30.45";  
         /** 
         * 不符合IP地址的长度范围 
         */  
         String threeAddress = "7.0.4";  
         /** 
         * 不符合IP地址的长度范围但是不符合IP取值范围 
         */  
         String fourAddress = "255.255.255.2567";  
           
         IpAdd ipAdd = new IpAdd();  
           
         //判断oneAddress是否是IP  
         System.out.println(ipAdd.isIP(oneAddress));  
           
         //判断twoAddress是否是IP  
         System.out.println(ipAdd.isIP(twoAddress));  
           
         //判断threeAddress是否是IP  
         System.out.println(ipAdd.isIP(threeAddress));  
           
         //判断fourAddress是否是IP  
         System.out.println(ipAdd.isIP(fourAddress));  
    }  
  
}
Copy after login

正则表达式定义了字符串的模式。

正则表达式可以用来搜索、编辑或处理文本。

正则表达式并不仅限于某一种语言,但是在每种语言中有细微的差别。

更多java知识请关注java基础教程

The above is the detailed content of Java determines whether ip. For more information, please follow other related articles on the PHP Chinese website!

Related labels:
source:php.cn
Statement of this Website
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn
Popular Tutorials
More>
Latest Downloads
More>
Web Effects
Website Source Code
Website Materials
Front End Template
About us Disclaimer Sitemap
php.cn:Public welfare online PHP training,Help PHP learners grow quickly!