代码篇之AOP框架

AopFrameworkTest类

public class AopFrameworkTest {
    public static void main(String[] args) throws Exception {
        InputStream ips = AopFrameworkTest.class.getResourceAsStream("config.properties");
        Object bean = new BeanFactory(ips).getBean("xxx");
        System.out.println(bean.getClass().getName());
        ((Collection)bean).clear();
    }
}

ProxyFactoryBean类

public class ProxyFactoryBean {

    private Advice advice;
    private Object target;
    
    public Advice getAdvice() {
        return advice;
    }

    public void setAdvice(Advice advice) {
        this.advice = advice;
    }

    public Object getTarget() {
        return target;
    }

    public void setTarget(Object target) {
        this.target = target;
    }

    public Object getProxy() {
        Object proxy3 = Proxy.newProxyInstance(
                target.getClass().getClassLoader(),
                target.getClass().getInterfaces(),
                new InvocationHandler(){
                
                    public Object invoke(Object proxy, Method method, Object[] args)
                            throws Throwable {
                        advice.beforeMethod(method);
                        Object retVal = method.invoke(target, args);
                        advice.afterMethod(method);
                        return retVal;                        
                    }
                }
                );
        return proxy3;
    }

}

BeanFactory类

public class BeanFactory {
    Properties props = new Properties();
    public BeanFactory(InputStream ips){
        try {
            props.load(ips);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
    
    public Object getBean(String name){
        String className = props.getProperty(name);
        Object bean = null;
        try {
            Class clazz = Class.forName(className);
            bean = clazz.newInstance();
        } catch (Exception e) {
            e.printStackTrace();
        } 
        if(bean instanceof ProxyFactoryBean){
            Object proxy = null;
            ProxyFactoryBean proxyFactoryBean = (ProxyFactoryBean)bean;
            try {
                Advice advice = (Advice)Class.forName(props.getProperty(name + ".advice")).newInstance();
                Object target = Class.forName(props.getProperty(name + ".target")).newInstance();
                proxyFactoryBean.setAdvice(advice);
                proxyFactoryBean.setTarget(target);
                proxy = proxyFactoryBean.getProxy();
            } catch (Exception e) {
                e.printStackTrace();
            }
            return proxy;
        }
        return bean;
    }
}

config.properties文件

#xxx=java.util.ArrayList
xxx=cn.itcast.day3.aopframework.ProxyFactoryBean
xxx.advice=cn.itcast.day3.MyAdvice
xxx.target=java.util.ArrayList