java - 正则表达式:如何包含 "if"条件字符

Question

我正在 java 中使用正则表达式制作日期提取器。问题是日期是 20-05-2014 而我的程序正在提取 0-5-14。简而言之，我怎样才能得到我正在检查日期第二个字符的字符？

    int count = 0;
    String data = "HellowRoldsThisis20-05-2014. farhan_rock@gmail.comHellowRoldsThisis.farhan@gmail.com";
    String regexOfDate = "((?<=[0])[1-9]{2})|((?<=[12])[0-9])|((?<=[3])[01])\\.\\-\\_((?<=[0])[1-9])|((?<=[1])[0-2])\\.\\-\\_((?<=[2])[0-9]{4})"; \\THE PROBLEM
    String[] extractedDate = new String[1000];
    Pattern patternDate = Pattern.compile(regexOfDate);
    Matcher matcherDate = patternDate.matcher(data);

    while(matcherDate.find()){           
        System.out.println("Date "+count+"Start: "+matcherDate.start());
        System.out.println("Date "+count+"End  : "+matcherDate.end());
        extractedDate[count] = data.substring(matcherDate.start(), matcherDate.end());
        System.out.println("Date Extracted: "+extractedDate[count]);
    }

Answer 1

你可以试试正则表达式:

// (0[1-9]|[12][0-9]|[3][01])[._-](0[1-9]|1[0-2])[._-](2[0-9]{3})
"(0[1-9]|[12][0-9]|[3][01])[._-](0[1-9]|1[0-2])[._-](2[0-9]{3})"