正则表达式

见 Java 正则表达式 | 菜鸟教程 (runoob.com)

捕获组 示例代码

import java.util.regex.Matcher;
import java.util.regex.Pattern;
 
public class RegexMatches {
    public static void main( String[] args ){
 
      // 按指定模式在字符串查找
      String line = "This order was placed for QT3000! OK?";
      String pattern = "(\\D*)(\\d+)(.*)";
 
      // 创建 Pattern 对象
      Pattern r = Pattern.compile(pattern);
 
      // 现在创建 matcher 对象
      Matcher m = r.matcher(line);
      if (m.find( )) {
         System.out.println("Found value: " + m.group(0) );
         System.out.println("Found value: " + m.group(1) );
         System.out.println("Found value: " + m.group(2) );
         System.out.println("Found value: " + m.group(3) ); 
      } else {
         System.out.println("NO MATCH");
      }
   }
}

sout：

Found value: This order was placed for QT3000! OK?
Found value: This order was placed for QT
Found value: 3000
Found value: ! OK?