java - java中的正则表达式

Question

我想通过正则表达式在字符串中搜索“$_POST['something']”。使用以下正则表达式通过文本板进行了尝试。".*$_POST\['[a-zA-z0-9]*'\].*"

当在java中使用相同时，它现在正在工作。?

Answer 1

您不需要开头和结尾.*，但您确实需要转义 ，$因为它具有字符串零宽度结尾的特殊含义。

\\$_POST\\['[a-zA-Z0-9]*'\\]

Answer 2

用这个：

"\\$_POST\\['([a-zA-Z0-9]*)'\\]"

像这样的符号$在正则表达式中有特定的含义。因此，您需要在它们前面加上\

Answer 3

您可以将作为字符串给出的正则表达式模式与String 类的match(...) 方法一起使用。它返回一个.boolean

String a = "Hello, world! $_POST['something'] Test!";
String b = "Hello, world! $_POST['special!!!char'] Test!";
String c = "Hey there $_GET['something'] foo bar";

String pattern = ".*\\$_POST\\['[A-Za-z0-9]+'\\].*";

System.out.println ("a matches? " + Boolean.toString(a.matches(pattern)));
System.out.println ("b matches? " + Boolean.toString(b.matches(pattern)));
System.out.println ("c matches? " + Boolean.toString(c.matches(pattern)));

您还可以使用Pattern和 Matcher 对象来重用模式以供多种用途：

String[] array = {
    "Hello, world! $_POST['something'] Test!",
    "Hello, world! $_POST['special!!!char'] Test!",
    "Hey there $_GET['something'] foo bar"
};

String strPattern = ".*\\$_POST\\['[A-Za-z0-9]+'\\].*";
Pattern p = Pattern.compile(strPattern);

for (int i=0; i<array.length; i++) {
    Matcher m = p.matcher(array[i]);
    System.out.println("Expression:  " + array[i]);
    System.out.println("-> Matches?  " + Boolean.toString(m.matches()));
    System.out.println("");
}

输出：

Expression:  Hello, world! $_POST['something'] Test!
-> Matches?  true

Expression:  Hello, world! $_POST['special!!!char'] Test!
-> Matches?  false

Expression:  Hey there $_GET['something'] foo bar
-> Matches?  false