Java 反射之 TypeVariable

TypeVariable是类型变量（泛型变量），在Java 反射之 GenericDeclaration中提到，Java中可以声明泛型变量的地方有三个class，contructor和method，TypeVariable接口的声明如下：

public interface TypeVariable<D extends GenericDeclaration> extends Type, AnnotatedElement {
    Type[] getBounds();  
    D getGenericDeclaration();
    String getName();
    AnnotatedType[] getAnnotatedBounds();
}

1. getBounds是拿获取类型变量的边界
2. getGenericDeclaration是获取到声明类型变量的语法元素，哪个class，哪个class的哪个构造方法，哪个class的哪个方法；
3. 
   

下面以在class上的TypeVariable为例，在contructor和method上是一样的；

public class TypeVariableSample<T extends @Location("Serializable") Serializable & @Location("Comparable<T>") Comparable<T>> {

}

public static void main(String[] args) {
    TypeVariable<Class<TypeVariableSample>>[] typeParameters = TypeVariableSample.class.getTypeParameters();

    for (int i = 0; i < typeParameters.length; i++) {
      TypeVariable<Class<TypeVariableSample>> typeVariable = typeParameters[i];
      System.out.println(typeVariable.getName());
      System.out.println(typeVariable.getGenericDeclaration());

      Type[] bounds = typeVariable.getBounds();
      for (int j = 0; j < bounds.length; j++) {
        Type bound = bounds[j];
        System.out.println(bound.getTypeName());
      }
      AnnotatedType[] annotatedBounds = typeVariable.getAnnotatedBounds();
      for (int j = 0; j < annotatedBounds.length; j++) {
        StringBuilder sb = new StringBuilder();
        AnnotatedType annotatedType = annotatedBounds[j];
        System.out.println("AnnotatedType:" + annotatedType.getType());
        Annotation[] annotations = annotatedType.getDeclaredAnnotations();
        for (int k = 0; k < annotations.length; k++) {
          Annotation annotation = annotations[k];
          sb.append(annotation);
        }
        sb.append(" "+ annotatedType.getType().getTypeName());
        System.out.println(sb.toString());
      }
    }
  }