正则表达式^

^只有在字符组的开头才是元字符，如果不在开头，就是普通字符，匹配它自身

package com.liguogang.utils;

import java.util.regex.Pattern;

public class RegexUtil {
    
    

    public static void main(String[] args) {
    
    
        String regex = "[^0-9]";
        match(1, "匹配字母", regex, "a");
        match(2, "匹配数字", regex, "9");
        match(3, "匹配^", regex, "^");
        regex = "[0^9]";
        match(4, "匹配^", regex, "^");
        match(5, "匹配^", regex, "9");

    }

    // 默认模式
    public static boolean match(int order, String description, String regex, String input) {
    
    
        if (null == input) {
    
    
            return false;
        }
        boolean matches = Pattern
                .compile(regex)
                .matcher(input)
                .matches();
        System.out.println(String.format("-----------------%s.match %s------------------", order, description));
        System.out.println(String.format("<regex>%s</regex>", regex));
        System.out.println(String.format("<input>%s</input>", input));
        System.out.println(String.format("<matches>%s</matches>", matches));
        return matches;
    }

}

D:\Java\jdk1.8.0_181\bin\java.exe "-javaagent:D:\devTools\idea\IntelliJ IDEA 2019.3.1\lib\idea_rt.jar=52793:D:\devTools\idea\IntelliJ IDEA 2019.3.1\bin" -Dfile.encoding=UTF-8 -classpath D:\Java\jdk1.8.0_181\jre\lib\charsets.jar;D:\Java\jdk1.8.0_181\jre\lib\deploy.jar;D:\Java\jdk1.8.0_181\jre\lib\ext\access-bridge-64.jar;D:\Java\jdk1.8.0_181\jre\lib\ext\cldrdata.jar;D:\Java\jdk1.8.0_181\jre\lib\ext\dnsns.jar;D:\Java\jdk1.8.0_181\jre\lib\ext\jaccess.jar;D:\Java\jdk1.8.0_181\jre\lib\ext\jfxrt.jar;D:\Java\jdk1.8.0_181\jre\lib\ext\localedata.jar;D:\Java\jdk1.8.0_181\jre\lib\ext\nashorn.jar;D:\Java\jdk1.8.0_181\jre\lib\ext\sunec.jar;D:\Java\jdk1.8.0_181\jre\lib\ext\sunjce_provider.jar;D:\Java\jdk1.8.0_181\jre\lib\ext\sunmscapi.jar;D:\Java\jdk1.8.0_181\jre\lib\ext\sunpkcs11.jar;D:\Java\jdk1.8.0_181\jre\lib\ext\zipfs.jar;D:\Java\jdk1.8.0_181\jre\lib\javaws.jar;D:\Java\jdk1.8.0_181\jre\lib\jce.jar;D:\Java\jdk1.8.0_181\jre\lib\jfr.jar;D:\Java\jdk1.8.0_181\jre\lib\jfxswt.jar;D:\Java\jdk1.8.0_181\jre\lib\jsse.jar;D:\Java\jdk1.8.0_181\jre\lib\management-agent.jar;D:\Java\jdk1.8.0_181\jre\lib\plugin.jar;D:\Java\jdk1.8.0_181\jre\lib\resources.jar;D:\Java\jdk1.8.0_181\jre\lib\rt.jar;D:\Java\jdk1.8.0_181\lib\tools.jar;E:\project\top\target\classes com.liguogang.utils.RegexUtil
-----------------1.match 匹配字母------------------
<regex>[^0-9]</regex>
<input>a</input>
<matches>true</matches>
-----------------2.match 匹配数字------------------
<regex>[^0-9]</regex>
<input>9</input>
<matches>false</matches>
-----------------3.match 匹配^------------------
<regex>[^0-9]</regex>
<input>^</input>
<matches>true</matches>
-----------------4.match 匹配^------------------
<regex>[0^9]</regex>
<input>^</input>
<matches>true</matches>
-----------------5.match 匹配^------------------
<regex>[0^9]</regex>
<input>9</input>
<matches>true</matches>

Process finished with exit code 0