Java代理模式详解：静态代理、JDK动态代理与Cglib动态代理

// 火车票销售接口
public interface TicketService {
void checkAvailability();
void purchase();
}
// 12306官方售票服务
public class OfficialTicketService implements TicketService {
@Override
public void checkAvailability() {
System.out.println("查询结果显示：无票");
}
@Override
public void purchase() {
System.out.println("购票成功！");
}
}

public class ThirdPartyTicketService implements TicketService {
private OfficialTicketService officialService;

public ThirdPartyTicketService(OfficialTicketService officialService) {
this.officialService = officialService;
}

@Override
public void checkAvailability() {
System.out.println("----------开始查询----------");
officialService.checkAvailability();
System.out.println("----------查询结束----------");
}

@Override
public void purchase() {
System.out.println("----------开始购票----------");
officialService.purchase();
System.out.println("----------购票结束----------");
}
}

TicketService service = new ThirdPartyTicketService(new OfficialTicketService());
service.checkAvailability();
service.purchase();

public class DynamicProxy implements InvocationHandler {
private Object target;

public Object bind(Object target) {
this.target = target;
return Proxy.newProxyInstance(
target.getClass().getClassLoader(),
target.getClass().getInterfaces(),
this
);
}

@Override
public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
System.out.println("----------开始执行方法----------");
Object result = method.invoke(target, args);
System.out.println("----------方法执行完毕----------");
return result;
}
}

TicketService service = (TicketService) new DynamicProxy().bind(new OfficialTicketService());
service.checkAvailability();
service.purchase();

import net.sf.cglib.proxy.Enhancer;
import net.sf.cglib.proxy.MethodInterceptor;
import net.sf.cglib.proxy.MethodProxy;

public class CglibDynamicProxy implements MethodInterceptor {
private Object target;

public Object createProxy(Object target) {
this.target = target;
Enhancer enhancer = new Enhancer();
enhancer.setSuperclass(this.target.getClass());
enhancer.setCallback(this);
return enhancer.create();
}

@Override
public Object intercept(Object obj, Method method, Object[] args, MethodProxy proxy) throws Throwable {
System.out.println("----------开始执行方法----------");
Object result = proxy.invokeSuper(obj, args);
System.out.println("----------方法执行完毕----------");
return result;
}
}

TicketService service = (TicketService) new CglibDynamicProxy().createProxy(new OfficialTicketService());
service.checkAvailability();
service.purchase();