我想封装一个简单的POJO类。问题是,我事先不知道该类的任何内容,只知道它是具有setter和getter的POJO。我想用我的代理类替换这个类,这样每当客户端调用getter或setter时,我就能拦截该调用。因此,当调用被拦截时,我想要进行一些预先的get(或set)操作,然后调用getter(或setter),最后再进行一些post-get(或set)操作。 我是这样创建代理的
private Pojo generatePojoProxy(Class<? extends PojoInterface> myPojo) {
Class<?> PojoProxyClass;
PojoProxyClass = new ByteBuddy()
.subclass(myPojo)
.method(ElementMatchers.nameStartsWith("get"))
.intercept(MethodDelegation.to(GetterInterceptor.class))
.method(ElementMatchers.nameStartsWith("set"))
.intercept(MethodDelegation.to(SetterInterceptor.class))
.name("Proxy" + myPojo.getName())
.make()
.load(myPojo.getClassLoader(), ClassLoadingStrategy.Default.WRAPPER)
.getLoaded();
Object pojoProxyInstance = null;
try {
pojoProxyInstance = PojoProxyClass.newInstance();
} catch (InstantiationException | IllegalAccessException e) {
e.printStackTrace();
}
return (Pojo) pojoProxyInstance;
}
我的GetterInterceptor看起来像这样
public class GetterInterceptor {
@RuntimeType
public static Object intercept(@AllArguments Object[] allArguments, @Origin Method method, @Super(proxyType = TargetType.class) Object delegate) {
preGetHandle();
Object result = null;
try {
result = method.invoke(delegate, allArguments);
} catch (InvocationTargetException | IllegalAccessException e) {
e.printStackTrace();
}
postGetHandle();
return result;
}
private static void preGetHandle() {}
private static void postGetHandle() {}
Setter看起来是一样的。
但是当我从我的Proxyclass实例设置和获取某些内容时,它比使用初始的Pojo类实例慢得多(1.5-2倍)。 我做错了什么吗?我相信,一定有办法让它更快。
非常感谢您的帮助!
我是这样测试性能的:
public class Main {
private static final int LOOP_COUNT = 10_000_000;
public static void main(String[] args) throws InstantiationException, IllegalAccessException {
Pojo pojo = new Pojo();
Pojo myProxy = (Pojo) ProxyFactory.getInstance().getProxy(Pojo.class);
testTime(pojo);
testTime(myProxy);
}
private static void testTime(Pojo pojo) {
long startTime = System.currentTimeMillis();
Random random = new Random();
long totalSum = 0;
for (int i = 0; i<LOOP_COUNT; i++){
pojo.setId(random.nextLong());
totalSum += pojo.getId();
}
long endTime = System.currentTimeMillis();
System.out.println(pojo.getClass() + " time = " + (endTime-startTime) + " total= " + totalSum);
}
我的结果如下:
class Pojo time = 288 total= 1060564671495946244
class ProxyPojo time = 738 total= 5879857558672375335