如何使用JDT判断类是AnnotationDeclaration还是TypeDeclaration

Question

我正在使用 JDT ASTParser 来解析给定文件夹中的所有 Java 文件。我写了以下代码：

private void parse(String fileContent) {
    // TODO Auto-generated method stub
    //advise the parser to parse the code following to the Java Language Specification, Third Edition.
    ASTParser parser = ASTParser.newParser(AST.JLS3); 
    // tell the parser, that it has to expect an ICompilationUnit (a pointer to a Java file) as input.
    parser.setKind(ASTParser.K_COMPILATION_UNIT);       
    parser.setSource(fileContent.toCharArray());
    parser.setResolveBindings(true);
    final CompilationUnit cu = (CompilationUnit) parser.createAST(null);

    cu.accept(new ASTVisitor() {
        public boolean visit(AnnotationTypeDeclaration node) {

            System.out.println("Annotaion: " + node.getName());

            return true;
        }

        public boolean visit(TypeDeclaration node) {

            System.out.println("Type: " + node.getName());

            return true;
        }
    });     

}

问题是，有两种 Java 类：

• Bound2Processor.java 是一个普通的java类：TypeDeclaration

  package com.richardle;
  
  import ...;
  
  
  public class Bound2Processor extends AbstractAnnotationProcessor<Bound, CtMethod<?>> {
     ...
  }
  

• Bound.java 为注解声明类：AnnotationTypeDeclaration

      package com.richardle;    
      public @interface Bound {
          double min(); 
      }
  

  但是在运行代码时，我得到了输出：

  File: D:\SOFTWARE\Android\SpoonTest\src\com\richardle\Bound.java // no thing print here
  File: D:\SOFTWARE\Android\SpoonTest\src\com\richardle\Bound2Processor.java
  Type: Bound2Processor
  

问题是注释类的名称没有打印出来。也许 ASTParser 没有调用函数public boolean visit(AnnotationTypeDeclaration node)。你能告诉我为什么 ASTParser 忽略这个函数吗？又如何判断一个类是普通类还是注解声明？

Answer 1

只有在 Java 合规性设置为大于 1.5 时，ASTParser 才会解析注解。

来自 ASTParser Javadoc：

为了解析 1.5 的代码，一些编译器选项需要设置为 1.5

所以你需要在你的代码中添加以下几行：

Map options = JavaCore.getOptions();
JavaCore.setComplianceOptions(JavaCore.VERSION_1_5, options);
parser.setCompilerOptions(options);

编辑

这是我用于测试的完整 parse 方法：

public static void parse(String fileContent) {
    //advise the parser to parse the code following to the Java Language Specification, Third Edition.
    ASTParser parser = ASTParser.newParser(AST.JLS3); 
    Map options = JavaCore.getOptions();
    JavaCore.setComplianceOptions(JavaCore.VERSION_1_5, options);
    parser.setCompilerOptions(options);

    // tell the parser, that it has to expect an ICompilationUnit (a pointer to a Java file) as input.
    parser.setKind(ASTParser.K_COMPILATION_UNIT);       
    parser.setSource(fileContent.toCharArray());
    parser.setResolveBindings(true);
    final CompilationUnit cu = (CompilationUnit) parser.createAST(null);

    cu.accept(new ASTVisitor() {
        public boolean visit(AnnotationTypeDeclaration node) {
            System.out.println("Annotaion: " + node.getName());
            return true;
        }

        public boolean visit(TypeDeclaration node) {
            System.out.println("Type: " + node.getName());
            return true;
        }
    });
}

这里是我提供给parse(String)的非常简单的类：

public @interface Bound {
    double min(); 
}

public class Bound2Processor {

}

这是输出：

Annotaion: Bound
Type: Bound2Processor