用正则表达式查找<和>之间的所有单词

Question

我想在String 之间<和之间找到单词>.

例如:

String str=your mobile number is <A> and username is <B> thanks <C>;

我想A,B,C从字符串.

我试过了

import java.util.regex.*;

public class Main
{
  public static void main (String[] args)
  {
     String example = your mobile number is <A> and username is <B> thanks <C>;
     Matcher m = Pattern.compile("\\<([^)]+)\\>").matcher(example);
     while(m.find()) {
       System.out.println(m.group(1));    
     }
  }
}

我在做什么有什么问题？

Answer 1

用下面的习惯和向后引用获取值你A,B和C占位符:

String example = "your mobile number is <A> and username is <B> thanks <C>";
//                           ? left delimiter - no need to escape here
//                           | ? group 1: 1+ of any character, reluctantly quantified
//                           | |   ? right delimiter
//                           | |   |
Matcher m = Pattern.compile("<(.+?)>").matcher(example);
while (m.find()) {
    System.out.println(m.group(1));
}

产量

A
B
C

注意

如果您喜欢没有索引后引用和"环顾四周"的解决方案,您可以使用以下代码实现相同的目标:

String example = "your mobile number is <A> and username is <B> thanks <C>";
//                            ? positive look-behind for left delimiter
//                            |    ? 1+ of any character, reluctantly quantified
//                            |    |   ? positive look-ahead for right delimiter
//                            |    |   |
Matcher m = Pattern.compile("(?<=<).+?(?=>)").matcher(example);
while (m.find()) {
    // no index for back-reference here, catching main group
    System.out.println(m.group());
}

我个人觉得后者在这种情况下不太可读.