正则表达式匹配完全限定类名 [英] Regular expression matching fully qualified class names

问题描述

在文本中匹配完全限定的Java类名称的最佳方法是什么？

示例： java.lang.Reflect ， java.util.ArrayList ， org.hibernate.Hibernate 。

解决方案

Java完全限定类名（让我们说N）具有结构

  NNNN 
  

N部分必须是Java标识符。 Java标识符不能以数字开头，但在初始字符后，它们可以使用字母和数字，下划线或美元符号的任意组合：

  ------------------------ ----------------------- 
 NN 
  

它们也不能是保留字（如 import ， true 或 null ）。如果您只想检查合理性，以上就足够了。

Java标识符可能包含任何Unicode字符，而不是包含任何Unicode字符的仅拉丁。如果你也想检查一下，使用Unicode字符类：

 （[\p {Letter} _ $] [\p {Letter} \p {Number} _ $] * \。）* [\p {Letter} _ $] [\p {Letter} \p {Number} _ $] * 
  

或简称

 （[\p {L} _ $] [\p {L} \p {N} _ $] * \。）* [\p {L} _ $] \p {L} \p {N} _ $] * 
  

Java语言规范（第3.8节）具有有效标识符名称的所有详细信息。 p>

另请参阅此问题的答案： Java Unicode变量名

What is the best way to match fully qualified Java class name in a text?

Examples: java.lang.Reflect, java.util.ArrayList, org.hibernate.Hibernate.

解决方案

A Java fully qualified class name (lets say "N") has the structure

N.N.N.N

The "N" part must be a Java identifier. Java identifiers cannot start with a number, but after the initial character they may use any combination of letters and digits, underscores or dollar signs:

([a-zA-Z_$][a-zA-Z\d_$]*\.)*[a-zA-Z_$][a-zA-Z\d_$]*
------------------------    -----------------------
          N                           N

They can also not be a reserved word (like import, true or null). If you want to check plausibility only, the above is enough. If you also want to check validity, you must check against a list of reserved words as well.

Java identifiers may contain any Unicode letter instead of "latin only". If you want to check for this as well, use Unicode character classes:

([\p{Letter}_$][\p{Letter}\p{Number}_$]*\.)*[\p{Letter}_$][\p{Letter}\p{Number}_$]*

or, for short

([\p{L}_$][\p{L}\p{N}_$]*\.)*[\p{L}_$][\p{L}\p{N}_$]*

The Java Language Specification, (section 3.8) has all details about valid identifier names.

Also see the answer to this question: Java Unicode variable names

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