正则表达式

字符

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字符分类

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预定义字符

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边界匹配

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Java例子

import java.util.regex.Matcher;import java.util.regex.Pattern;public class RegexMatches {    private static String pattern = "^[_A-Za-z0-9-]+(\\.[_A-Za-z0-9-]+)*@[A-Za-z0-9]+(\\.[A-Za-z0-9]+)*(\\.[A-Za-z]{2,})$";    private static Pattern mypattern = Pattern.compile(pattern);    public static void main(String args[]) {        String valEmail1 = "[e-mail]";        String invalEmail1 = "[e-mail]";        String invalEmail2 = ".$$[e-mail]";        String valEmail2 = "[e-mail]";        System.out.println("Is Email ID1 valid? " + validateEMailID(valEmail1));        System.out.println("Is Email ID1 valid? " + validateEMailID(invalEmail1));        System.out.println("Is Email ID1 valid? " + validateEMailID(invalEmail2));        System.out.println("Is Email ID1 valid? " + validateEMailID(valEmail2));    }    public static boolean validateEMailID(String emailID) {        Matcher mtch = mypattern.matcher(emailID);        if (mtch.matches()) {            return true;        }        return false;    }}