今天突然看到spring aop,想到代理模式,就写了个动态代理的例子,但是有点不遂人愿,出错了,各位大牛帮我看下哪里错了.
程序里头可能是有死循环或递归调用所产生的?增大JVM的内存?
public interface Subject {
void opration();
}
public class RealSubject implements Subject {
@Override
public void opration() {
System.out.println("I am a RealSubject");
}
}
public class ProxyInvocationHandler implements InvocationHandler {
private Object beProxy;
public ProxyInvocationHandler(Object beProxy) {
super();
this.beProxy = beProxy;
}
@Override
public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
System.out.println("proxy class:" + proxy + "proxy method:" + method);
return method.invoke(beProxy, args);
}
}
public class TestDynamicProxy {
public static void main(String[] args) {
Subject proxyClass = (Subject) Proxy.newProxyInstance(Subject.class.getClassLoader(),
new Class[] { Subject.class },
new ProxyInvocationHandler(new RealSubject()));
proxyClass.opration();
}
}
Exception in thread "main" java.lang.StackOverflowError
at java.lang.AbstractStringBuilder.(AbstractStringBuilder.java:44)
at java.lang.StringBuilder.(StringBuilder.java:92)
at com.test.dynamic.proxy.ProxyInvocationHandler.invoke(ProxyInvocationHandler.java:32)
at com.sun.proxy.$Proxy0.toString(Unknown Source)
at java.lang.String.valueOf(String.java:2826)
at java.lang.StringBuilder.append(StringBuilder.java:115)
at com.test.dynamic.proxy.ProxyInvocationHandler.invoke(ProxyInvocationHandler.java:32)
at com.sun.proxy.$Proxy0.toString(Unknown Source)
at java.lang.String.valueOf(String.java:2826)
at java.lang.StringBuilder.append(StringBuilder.java:115)
at com.test.dynamic.proxy.ProxyInvocationHandler.invoke(ProxyInvocationHandler.java:32)
at com.sun.proxy.$Proxy0.toString(Unknown Source)
at java.lang.String.valueOf(String.java:2826)
at java.lang.StringBuilder.append(StringBuilder.java:115)
proxy.toString()递归调用InvocationHandler的invoke方法，导致堆栈溢出。搜一下$Proxy0的源码就知道。
怎么解决呢 他并没有调用toString（）方法呀
字符串连接符号 +， 自动调用toString()