今天有同事问起，动态代理中的InvocationHandler的invoke方法的第一个参数。是代理类还是委托类(即被代理类). 其实这个参数是代理类。我们看一下生成的代理类就会明白：
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public
interface
ProxyInf {
public
void
say();
}
public
class
TestProxy{
public
void
say() {
System.out.println(
"nothing"
);
}
public
static
void
main(String args[])
throws
IOException{
byte
[] generateProxyClass = ProxyGenerator.generateProxyClass(
"ProxyImpl"
,
new
Class<?>[] { ProxyInf.
class
});
FileOutputStream fos =
new
FileOutputStream(
"c:\\ProxyImpl.class"
);
fos.write(generateProxyClass);
fos.close();
}
}
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反编译C盘下面的ProxyImpl.class类文件，你会发现：
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public
final
class
ProxyImpl
extends
Proxy
implements
ProxyInf
{
private
static
Method m3;
private
static
Method m1;
private
static
Method m0;
private
static
Method m2;
public
ProxyImpl(InvocationHandler paramInvocationHandler)
throws
{
super
(paramInvocationHandler);
}
public
final
void
say()
throws
{
try
{
this
.h.invoke(
this
, m3,
null
);
return
;
}
catch
(RuntimeException localRuntimeException) {
throw
localRuntimeException;
}
catch
(Throwable localThrowable){
}
throw
new
UndeclaredThrowableException(localThrowable);
}
...
}
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当你调用代理类的say方时，他调用的是InvokeHandler的invoke方法，并把自个做首参传了进去。
就这样吧.
本文转自 anranran 51CTO博客，原文链接:http://blog.51cto.com/guojuanjun/1221281
