类反射以获取类名称，类型变量，接口，注释

/** 
来 自 
时代Java公众号 - nowjava.com
**/

import java.lang.annotation.Annotation;

import java.lang.reflect.Modifier;

import java.lang.reflect.Type;

import java.lang.reflect.TypeVariable;

import java.util.Arrays;

import java.util.ArrayList;

import java.util.List;

import static java.lang.System.out;


public class ClassDeclarationSpy {

    public static void main(String... args) {

        try {

            Class<?> c = Class.forName(args[0]);

            out.format("Class:%n  %s%n%n", c.getCanonicalName());

            out.format("Modifiers:%n  %s%n%n",/**来 自 NowJava.com**/

                    Modifier.toString(c.getModifiers()));


            out.format("Type Parameters:%n");

            TypeVariable[] tv = c.getTypeParameters();

            if (tv.length != 0) {

                out.format("  ");

                for (TypeVariable t : tv)

                    out.format("%s ", t.getName());

                out.format("%n%n");

            } else {

                out.format("  -- No Type Parameters --%n%n");

            }


            out.format("Implemented Interfaces:%n");

            Type[] intfs = c.getGenericInterfaces();

            if (intfs.length != 0) {

                for (Type intf : intfs)

                    out.format("  %s%n", intf.toString());

                out.format("%n");

            } else {

                out.format("  -- No Implemented Interfaces --%n%n");

            }


            out.format("Inheritance Path:%n");

            List<Class> l = new ArrayList<Class>();

            printAncestor(c, l);

            if (l.size() != 0) {

                for (Class<?> cl : l)

                    out.format("  %s%n", cl.getCanonicalName());

                out.format("%n");

            } else {

                out.format("  -- No Super Classes --%n%n");

            }


            out.format("Annotations:%n");

            Annotation[] ann = c.getAnnotations();

            if (ann.length != 0) {

                for (Annotation a : ann)

                    out.format("  %s%n", a.toString());

                out.format("%n");

            } else {

                out.format("  -- No Annotations --%n%n");

            }


            // production code should handle this exception more gracefully

        } catch (ClassNotFoundException x) {

            x.printStackTrace();

        }

    }


    private static void printAncestor(Class<?> c, List<Class> l) {

        Class<?> ancestor = c.getSuperclass();

        if (ancestor != null) {

            l.add(ancestor);

            printAncestor(ancestor, l);

        }

    }

}