正则表达式获取正确的java类名

Question

出于某种原因，我想扫描 java 文件的内容（例如 TagMatchingInterface.java）并通过正则表达式获取类名（TagMatchingInterface），但我的正则表达式匹配不正确的类名，因为有一些关键字（类/接口/枚举）隐藏在评论中：

/**
 *
 * @author XXXX
 * Introduction: A common interface that judges all kinds of algorithm tags.
 * some other comment
 */
public class TagMatchingInterface 
{
  // content
  public class InnerClazz{
    // content
  }
}

这是我的模式：

public Pattern CLASS_PATTERN = Pattern.compile("(?:public\\s)?(?:.*\\s)?(class|interface|enum)\\s+([$_a-zA-Z][$_a-zA-Z0-9]*)");
....
Matcher matcher = CLASS_PATTERN.matcher(content);
if (matcher.find()) {
   System.out.println(match.group(2));
}

知道我的正则表达式吗？

Answer 1

描述

(?<=\n|\A)(?:public\s)?(class|interface|enum)\s([^\n\s]*)

此正则表达式执行以下操作：

• 允许字符串以public或不以
• 是class或interface或enum
• 捕获名称

注意，我建议使用全局和不区分大小写的标志

例子

现场示例

https://regex101.com/r/vR0iK3/1

示例文本

/**
 *
 * @author XXXX
 * Introduction: A common interface that judges all kinds of algorithm tags.
 * some other comment
 */
public class TagMatchingInterface 
{
  // content
  public class InnerClazz{
    // content
  }
}

样本匹配

[0][0] = public class TagMatchingInterface
[0][1] = class
[0][2] = TagMatchingInterface

捕获组：

• 第 0 组获得整个比赛
• 第 1 组获得课程
• 第 2 组获得名称

解释

NODE                     EXPLANATION
----------------------------------------------------------------------
  (?<=                     look behind to see if there is:
----------------------------------------------------------------------
    \n                       '\n' (newline)
----------------------------------------------------------------------
   |                        OR
----------------------------------------------------------------------
    \A                        Start of the string
----------------------------------------------------------------------
  )                        end of look-behind
----------------------------------------------------------------------
  (?:                      group, but do not capture (optional
                           (matching the most amount possible)):
----------------------------------------------------------------------
    public                   'public'
----------------------------------------------------------------------
    \s                       whitespace (\n, \r, \t, \f, and " ")
----------------------------------------------------------------------
  )?                       end of grouping
----------------------------------------------------------------------
  (                        group and capture to \1:
----------------------------------------------------------------------
    class                    'class'
----------------------------------------------------------------------
   |                        OR
----------------------------------------------------------------------
    interface                'interface'
----------------------------------------------------------------------
   |                        OR
----------------------------------------------------------------------
    enum                     'enum'
----------------------------------------------------------------------
  )                        end of \1
----------------------------------------------------------------------
  \s                       whitespace (\n, \r, \t, \f, and " ")
----------------------------------------------------------------------
  (                        group and capture to \2:
----------------------------------------------------------------------
    [^\n\s]*                 any character except: '\n' (newline),
                             whitespace (\n, \r, \t, \f, and " ") (0
                             or more times (matching the most amount
                             possible))
----------------------------------------------------------------------
  )                        end of \2
----------------------------------------------------------------------