Java基础之动态代理Cglib详解

package proxy.cglib;


public class OrderServiceImpl {
    
    public String preOrder(String orderNo) {
        System.out.println("OrderServiceImpl.preOrder" + orderNo);
        return "下单成功";
    }

    
    public String list() {
        return "list";
    }
}

package proxy.cglib;

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

import java.lang.reflect.Method;
import java.lang.reflect.Parameter;
import java.util.Objects;


public class CglibProxyFactory implements MethodInterceptor {

    
    public Object creatProxyedObj(Class<?> clazz) {
        Enhancer enhancer = new Enhancer();
        enhancer.setSuperclass(clazz);
        enhancer.setCallback(this);
        return enhancer.create();
    }

    
    @Override
    public Object intercept(Object proxyObject, Method method, Object[] args, MethodProxy methodProxy) throws Throwable {
        // 判断方法参数 如果是null || 参数格式 <= 0
        if (Objects.isNull(args) || args.length <= 0) {
            return methodProxy.invokeSuper(proxyObject, args);
        }
        /// // 判断这个方法上是否包含某个注解
        // if (method.isAnnotationPresent(Async.class)) {
        //     // ....进行一顿增强
        //     // return method.invoke(proxy, arg);
        // }
        Parameter[] parameters = method.getParameters();
        Parameter parameter = parameters[0];
        Class<?> type = parameter.getType();
        // 类型为String
        if (type == String.class) {
            String orderNo = (String) args[0];
            if (Objects.nonNull(orderNo) && orderNo.length() < 10) {
                throw new RuntimeException("订单号错误");
            }
        }
        String result = (String) methodProxy.invokeSuper(proxyObject, args);
        if (Objects.equals(result, "下单成功")) {
            System.out.println("发动订单短信");
        }
        return result;
    }

}