相关疑难解决方法(0)

所以我正在玩geotools,我想我会代理他们的一个数据访问类,并跟踪它们在代码中的使用方式.

我编写了一个动态代理并在其中包含了一个FeatureSource(接口),并且很高兴.然后我想看看一些由featureSource返回,以及在传递对象,因为FeatureSource做的主要工作是返回的FeatureCollection(FeatureSource类似于一个SQL数据源,并以的FeatureCollection SQL语句).

在我的InvocationHandler我刚刚通过的调用底层对象,打印出目标类/方法/指定参数和结果,我去了,但是对于返回的FeatureCollection(另一个接口)调用,我裹着该对象在我的代理服务器(在相同的类,但一个新的实例,应该不重要吗？)并返回它.BAM!Classcast异常:

java.lang.ClassCastException: $Proxy5 cannot be cast to org.geotools.feature.FeatureCollection  
    at $Proxy4.getFeatures(Unknown Source)  
    at MyClass.myTestMethod(MyClass.java:295)  

调用代码:

FeatureSource<SimpleFeatureType, SimpleFeature> featureSource = ... // create the FS
featureSource = (FeatureSource<SimpleFeatureType, SimpleFeature>) FeatureSourceProxy.newInstance(featureSource, features);
featureSource.getBounds();// ok
featureSource.getSupportedHints();// ok

DefaultQuery query1 = new DefaultQuery(DefaultQuery.ALL);
FeatureCollection<SimpleFeatureType, SimpleFeature> results = featureSource.getFeatures(query1); //<- explosion here

代理人:

public class FeatureSourceProxy  implements java.lang.reflect.InvocationHandler {

private Object target;
private List<SimpleFeature> features;

public static Object newInstance(Object obj, List<SimpleFeature> features) {
return java.lang.reflect.Proxy.newProxyInstance(
    obj.getClass().getClassLoader(), 
    obj.getClass().getInterfaces(), 
    new FeatureSourceProxy(obj, features)
);
}

private …