public class ReflectDemo1 {public static void main(String[] args) throws ClassNotFoundException {//方式一(通过Class.forName的方式，括号中是包名.类名)常用Class clazz1 = Class.forName("xx.ReflectDemo1");//方式二(类名.class)Class clazz2 = ReflectDemo1.class;//方式三(创建类的实例对象，再通过getClass的方式)ReflectDemo1 ref = new ReflectDemo1();Class clazz3 = ref.getClass();System.out.println(clazz1 == clazz2);//trueSystem.out.println(clazz2 == clazz3);//true,三个字节码对象是同一个字节码对象
    }
}

public class ReflectDemo2 {private String name;public ReflectDemo2(String name) {super();this.name = name;}@Overridepublic String toString() {return "[name=" + name + "]";}public void method1(){System.out.println("你好啊");}public void method2(String name){System.out.println("hello"+name);}public static void main(String[] args) throws Exception {//通过反射获取有参构造,并通过有参构造创建对象Class clazz = Class.forName("course9.ReflectDemo2");Constructor c = clazz.getConstructor(String.class);ReflectDemo2 ref = (ReflectDemo2) c.newInstance("zx");System.out.println(ref);//通过反射获取成员变量并使用Field f = clazz.getDeclaredField("name");//获取姓名字段（暴力反射获取，即使是私有变量）f.setAccessible(true);//设置去除私有权限f.set(ref, "ls");System.out.println(ref);//通过反射获取方法并使用Method m1 = clazz.getMethod("method1");Method m2 = clazz.getMethod("method2",String.class);m1.invoke(ref);m2.invoke(ref,"张三");}
}

public class ReflectDemo3 {public static void main(String[] args) throws Exception {//使用反射越过泛型的检查ArrayList<Integer> list = new ArrayList<>();//创建一个存放整型的链表list.add(11);list.add(22);Class clazz = Class.forName("java.util.ArrayList");//获取java.util.ArrayList类的字节码对象Method m = clazz.getMethod("add", Object.class);//获取其中的add方法m.invoke(list, "abc");//链表中添加字符串System.out.println(list);}
}

public class ReflectDemo4 implements User{public static void main(String[] args) {ReflectDemo4 ref = new ReflectDemo4();ref.add();ref.delete();MyInvocationHandler m = new MyInvocationHandler(ref);//创建动态代理类(放入需要代理的对象)User user = (User) Proxy.newProxyInstance(ref.getClass().getClassLoader(), ref.getClass().getInterfaces(), m);//获取类加载器和接口
        System.out.println("-----------------------");user.add();user.delete();}@Overridepublic void add() {System.out.println("添加功能");
    }@Overridepublic void delete() {System.out.println("删除功能");
    }
}
interface User{public void add();public void delete();
}//动态代理类
class MyInvocationHandler implements InvocationHandler{private Object target;public MyInvocationHandler(Object target) {super();this.target = target;}@Overridepublic Object invoke(Object proxy, Method method, Object[] args) throws Throwable {System.out.println("权限校验");method.invoke(target, args);//执行被代理target对象的方法System.out.println("日志记录");return null;}}