java - 为我的代理类中的每个方法执行 InvocableHandler 调用方法

Question

我已经实现了一个动态代理，以便在我的方法开始之前执行一些操作。现在我在从代理类调用两个方法时遇到问题，代码如下:

动态代理类:

public class IPageProxy implements InvocationHandler {

    private Class <? extends IPage> screenClazz;

    public IPageProxy(final Class <? extends IPage> screenClazz) {
        this.screenClazz = screenClazz;
    }

    @SuppressWarnings("unchecked")
    public static <T extends IPage> T getInstance(final Class<? extends IPage> type)
            throws InstantiationException, IllegalAccessException {

        List<Class<?>> interfaces = new ArrayList<>();
        interfaces.addAll(Arrays.asList(type.getInterfaces()));

        return (T) Proxy.newProxyInstance(
                type.getClassLoader(),
                findInterfaces(type),
                new IPageProxy(type)
             );

    }


    static Class<?>[] findInterfaces(final Class<? extends IPage> type) {
        Class<?> current = type;

        do {
            final Class<?>[] interfaces = current.getInterfaces();

            if (interfaces.length != 0) {
                return interfaces;
            }
        } while ((current = current.getSuperclass()) != Object.class);

        throw new UnsupportedOperationException("The type does not implement any interface");
    }





    @Override
    public Object invoke(final Object proxy, final Method method, final Object[] args) throws InvocationTargetException,
            IllegalAccessException, IllegalArgumentException, InstantiationException, ParserConfigurationException, XPathExpressionException, NoSuchFieldException, SecurityException {

        // before method executed this code will be done
        System.out.println("*   Dynamic proxy invoke method executed for " +  method.getName());

        // Invoke original method
        return method.invoke(screenClazz.newInstance(), args);
    }
}

主类:

public static void main(String[] args) {
        try {
            //IEventDesignDialog a = new EventDesignDialog();
            IEventDesignDialog a  = (IEventDesignDialog)getInstance(EventDesignDialog.class);
            a.getEventType().getShow();

        } catch (InstantiationException | IllegalAccessException e) {
            e.printStackTrace();
        }
    }


    @SuppressWarnings("unchecked")
    public static <T extends IPage> T getInstance(final Class<? extends IPage> type) throws InstantiationException, IllegalAccessException {
        return (T) IPageProxy.getInstance(type);
    }

代理类:

public class EventDesignDialog implements IEventDesignDialog{


        private String show;


        private String dateAndTimeDisplayFormat;
        private String eventType;


        @Entity(visibileName = "Show")
        public IEventDesignDialog getShow() {
            System.out.println("get show method invokde successfully");
            return this;
        }

        @Entity(visibileName = "Date And Time display format")
        public IEventDesignDialog getDateAndTimeDisplayFormat() {
            System.out.println("get date and time display format method invokde successfully");
            return this;
        }

        @Entity(visibileName = "Event Type")
        public IEventDesignDialog getEventType() {
            System.out.println("get event type method invokde successfully");
            return this;
        }



}

实际输出:

***   Dynamic proxy invoke method executed for getEventType
get event type method invokde successfully
get show method invokde successfully**

如图所示，调用方法仅在初始化代理后的第一个方法调用时执行，第二个方法直接调用，无需代理功能。

我的目标是每次调用我的集合中出现的方法时都执行调用方法，预期结果应如下所示。

预期输出:

***   Dynamic proxy invoke method executed for getEventType
get event type method invokde successfully
*   Dynamic proxy invoke method executed for getShow
get show method invokde successfully**

如果需要更多解释，请告诉我。

Answer 1

我通过创建一个带有默认方法的接口(interface)来解决这个问题，该方法返回代理实例，然后在执行调用的方法功能后返回它:

更新的代码:

public interface IPage {
    default <T extends IPage> T getProxyInstance() {
        try {
            return (T) IPageProxy.getInstance(this.getClass());
        } catch (InstantiationException | IllegalAccessException e) {
            e.printStackTrace();
        }
        return null;
    }
}

我的页面界面:

@Page(path = "MyPath")
public interface IEventDesignDialog extends IPage{
    @Entity(visibileName = "Show")
    public IEventDesignDialog getShow();

    @Entity(visibileName = "Date And Time display format")
    public IEventDesignDialog getDateAndTimeDisplayFormat();

    @Entity(visibileName = "Event Type")
    public IEventDesignDialog getEventType();    
}

我的页面类:

@Page(path = "MyPath")
public class EventDesignDialog implements IEventDesignDialog{
        @Entity(visibileName = "Show")
        public IEventDesignDialog getShow() {
            System.out.println("get show method invokde successfully");
            return getProxyInstance();
        }

        @Entity(visibileName = "Date And Time display format")
        public IEventDesignDialog getDateAndTimeDisplayFormat() {
            System.out.println("get date and time display format method invokde successfully");
            return getProxyInstance();
        }

        @Entity(visibileName = "Event Type")
        public IEventDesignDialog getEventType() {
            System.out.println("get event type method invokde successfully");
            return getProxyInstance();
        }
}

主类:

public class Main {

    public static void main(String[] args) {
        try {
            IEventDesignDialog a  = ((IEventDesignDialog)getInstance(EventDesignDialog.class)).getEventType().getShow();

            ((IShowDesignDialog)getInstance(ShowDesignDialog.class)).getShowName().getShowType();
        } catch (InstantiationException | IllegalAccessException e) {
            e.printStackTrace();
        }
    }


    @SuppressWarnings("unchecked")
    public static <T extends IPage> T getInstance(final Class<? extends IPage> type) throws InstantiationException, IllegalAccessException {
        return (T) IPageProxy.getInstance(type);
    }

}

IProxy 页面保持不变，无需更改。