發(fā)生的事情是，首先您只代理第一次調(diào)用，然后您在非代理類上調(diào)用 getShow()，這就是為什么您會(huì)得到您提到的結(jié)果。如果你想實(shí)現(xiàn)你提到的目標(biāo)，你需要基于創(chuàng)建的實(shí)例而不是僅僅基于類創(chuàng)建另一個(gè)代理。
更新：我將提供示例代碼，您可以粘貼到任何 java 文件中并執(zhí)行它。在你看到 TODO 的地方，你可以根據(jù)你想要提供代理的方式放置你自己的邏輯。重要時(shí)刻見注。為了簡(jiǎn)化演示，我將所有類放在一個(gè)文件中。
import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;
import java.util.Arrays;
import java.util.List;
class Scratch {
public static void main(String[] args) {
try {
IEventDesignDialog a = proxy(EventDesignDialog.class);
a.getEventType().getShow();
a.getDateAndTimeDisplayFormat().getShow();
} catch (InstantiationException | IllegalAccessException e) {
e.printStackTrace();
}
}
@SuppressWarnings("unchecked")
private static <T extends IPage> T proxy(final Class<? extends IPage> type) throws InstantiationException, IllegalAccessException {
return (T) IPageProxy.proxy(type);
}
}
interface IPage{}
interface IEventDesignDialog extends IPage{
IEventDesignDialog getShow();
IEventDesignDialog getEventType();
IEventDesignDialog getDateAndTimeDisplayFormat();
}
class EventDesignDialog implements IEventDesignDialog{
public IEventDesignDialog getShow() {
System.out.println("get show method invoked successfully");
//NOTE: this will be treated as same proxy but not this
return this;
}
public IEventDesignDialog getDateAndTimeDisplayFormat() {
System.out.println("get date and time display format method invoked successfully");
// NOTE: we supply some iinstance which will be proxied
return new MyIEventDesignDialog();
}
public IEventDesignDialog getEventType() {
System.out.println("get event type method invoked successfully");
//NOTE: this will be treated as same proxy but not this
return this;
}
}
class IPageProxy implements InvocationHandler {
private IPage instance;
private List<Class<?>> interfaces;
public IPageProxy(IPage instance, List<Class<?>> interfaces) {
this.instance = instance;
this.interfaces = interfaces;
}
@SuppressWarnings("unchecked")
public static <T extends IPage> T proxy(final Class<? extends IPage> type)
throws InstantiationException, IllegalAccessException {
List<Class<?>> interfaces = Arrays.asList(type.getInterfaces());
//TODO: get interfaces properly recursively
return (T) Proxy.newProxyInstance(
type.getClassLoader(),
type.getInterfaces(),
new IPageProxy(type.newInstance(), interfaces)
);
}
@SuppressWarnings("unchecked")
public static <T extends IPage> T proxy(T object) {
//TODO: get interfaces properly recursively
List<Class<?>> interfaces = Arrays.asList(object.getClass().getInterfaces());
return (T) Proxy.newProxyInstance(
object.getClass().getClassLoader(),
object.getClass().getInterfaces(),
new IPageProxy(object, interfaces)
);
}
@Override
public Object invoke(final Object proxy, final Method method, final Object[] args) throws Exception {
// before method executed this code will be done
System.out.println("* Dynamic proxy invoke method executed for " + method.getName());
// Invoke original method
Object invoke = method.invoke(instance, args);
if (invoke == null) {
return null;
}
//If some of the method returns the original object
//we swap the returned object by our proxy
if (invoke == instance) {
return proxy;
}
//TODO: check if you want to swap in place
//other interfaces
if (interfaces.contains(method.getReturnType())) {
return IPageProxy.proxy((IPage)invoke);
}
return invoke;
}
}
class MyIEventDesignDialog implements IEventDesignDialog {
@Override
public IEventDesignDialog getShow() {
return null;
}
@Override
public IEventDesignDialog getEventType() {
return null;
}
@Override
public IEventDesignDialog getDateAndTimeDisplayFormat() {
return null;
}
}
輸出：
* Dynamic proxy invoke method executed for getEventType
get event type method invoked successfully
* Dynamic proxy invoke method executed for getShow
get show method invoked successfully
* Dynamic proxy invoke method executed for getDateAndTimeDisplayFormat
get date and time display format method invoked successfully
* Dynamic proxy invoke method executed for getShow
您可以從 Mockito 的工作方式中獲得靈感。請(qǐng)查看此頁面：https ://static.javadoc.io/org.mockito/mockito-core/2.27.0/org/mockito/Mockito.html#spy-T-
我知道它是用于測(cè)試的，但您仍然可以從中獲得想法。所以你可以在一個(gè)類和一個(gè)對(duì)象上應(yīng)用 spy() 來監(jiān)視它。
