Java注釋元素方法返回

Question

我有一個如下的自定義注釋。

@customelement(folder = "/path/")
public testMethod() {

}

如何使用下面的AbstractProcessor提取文件夾值，即“ / path /”？

public class CompileTimeAnnotationProcessor extends AbstractProcessor {

    @Override
    public boolean process(Set<? extends TypeElement> annotations, 
                           RoundEnvironment roundEnv) {
        Set<? extends Element> elements = roundEnv.getElementsAnnotatedWith(CustomAnnotation.class);
        for(Element te : elements){
          for (Element e : te.getEnclosedElements()) {
                     if (e.getSimpleName().toString().equals("folder")) {
                       //Here fetch method return value
                  }
           }
        }
        return true;
    }

}

Answer 1

我想您想做某事：

    @Override
    public boolean process(Set<? extends TypeElement> annotations, 
                           RoundEnvironment roundEnv) {
        Set<? extends Element> elements = roundEnv.getElementsAnnotatedWith(CustomAnnotation.class);
        for(Element te : elements){
          CustomAnnotation annotation = te.getAnnotation(CustomAnnotation.class);
          String folder = annotation.folder();
          //... do sth with folder in context of te. 
          //te represent annotated method, e.g. testMethod from your example
        }
        return true;
    }

還請記住使用@SupportedAnnotationTypes("package.CustomAnnotation")和@SupportedSourceVersion(SourceVersion.RELEASE_7)注釋您的CompileTimeAnnotationProcessor （或您要支持的任何Java語法版本）。

如果出現其他問題，建議閱讀這篇很棒的教程博客文章 。