Java Regex - 掩码信用卡号

Question

我有在字符串中屏蔽信用卡号的函数:

  public static String  replaceCreditCardNumber(String text){
         final String MASKCARD = "$1<MASKED>$2";
         final Pattern PATTERNCARD = 
            Pattern.compile("([0-9]{4})[0-9]{0,9}([0-9]{4})");    
         Matcher matcher = PATTERNCARD.matcher(text);
         if (matcher.find()) {
             return   matcher.replaceAll(MASKCARD);
         }
         return text;

    }

此函数在以下情况下工作正常:

    String text = "Aaaa bbbb aaa=1234567890123456 fdfdfd=aaa";
    String expected = "Aaaa bbbb aaa=1234<MASKED>3456 fdfdfd=aaa";
    assertEquals(expected,text);//OK

    String text = "Aaaa bbbb aaa=\"1234567890123456\" fdfdfd=aaa";
    String expected = "Aaaa bbbb aaa=\"1234<MASKED>3456\" fdfdfd=aaa";
    assertEquals(expected,text);

但是以下情况失败

        String text = "Aaaa bbbb aaa=1gfg23fgfg4567890123456 fdfdfd=aaa";
        String expected = "Aaaa bbbb aaa=1gfg23fgfg4567890123456 fdfdfd=aaa";
        assertEquals(expected,text);

我得到了

        aaa=1gfg23fgfg4567[<MASKED>]3456

我的正则表达式中缺少什么？

Answer 1

您应该使用单词边界来确保避免匹配不需要的输入:

final Pattern PATTERNCARD = 
        Pattern.compile("\\b([0-9]{4})[0-9]{0,9}([0-9]{4})\\b"); 

Working Demo