java - 字符串中允许的字符的正则表达式返回 false

Question

我有一个需求，如下所示

The following special characters are allowed with restrictions in the input string:

. ""(),:;<>@[\]

The restrictions for the special characters are that they must only be used when contained between quotation marks.

对于输入字符串中“:”的简单测试，我编写了如下代码:

private static void testEmailPattern() {
    String email = "Test\":\"mail";
    String PATTERN = "[\":\"]*";
    boolean isValidEmail = email.matches(PATTERN);
    System.out.println("Status: " + isValidEmail);
}

但是此代码返回 false 而不是 true。

编辑:阅读评论后，我修改了该代码，但它仍然显示错误。

我修改了我的代码，如下所示:

public class TestFeatures {
    private Pattern pattern;
    private Matcher matcher;

    private static final String PATTERN = "[.*\":\".*]*";

    public TestFeatures() {
        initEmailPattern();
    }

    private void initEmailPattern() {
        pattern = Pattern.compile(PATTERN);     
    }

    public boolean validate(final String hex) {
        matcher = pattern.matcher(hex);
        return matcher.matches();
    }

    /**
     * @param args
     */
    public static void main(String[] args) {
        testEmailPattern();
    }

    private static void testEmailPattern() {
        String email = "Test\":\"mail@mail.com";
        TestFeatures thisClazz = new TestFeatures();
        boolean isValidEmail = thisClazz.validate(email);
        System.out.println("Status: " + isValidEmail);
    }
}

Answer 1

您需要积极的前瞻性和积极的回顾。

(.*(?<=")[.\x20(),:;<>@\[\]"](?=").*)+

描述

示例代码

String[] tests = {
       "Test:mail",
       "Test\":\"mail",
       "Test\"ll",
       ".\".",
       "foo\"\"\""
};

String re = "(.*(?<=\")[.\\x20(),:;<>@\\[\\]\"](?=\").*)+";

int len=tests.length;
for(int i=0; i<len;i++) {
    System.out.format("Test %d: %s >> %s\n" , i+1, tests[i], tests[i].matches(re));
}

输出

Test 1: Test:mail >> false
Test 2: Test":"mail >> true
Test 3: Test"ll >> false
Test 4: .". >> false
Test 5: foo""" >> true