目标
ServiceImpl类中有一个私有方法MethodA,而ServiceImpl是被spring管理的,该类中有一些用@Autowired注入的依赖项,因此不能直接new来创建它的实例,需要通过spring来创建它的实例,那么该怎么测试该私有方法呢?
方案
测试类
public class Test {
@Autowired
ServiceImpl serviceImpl;
@Test
public void test() throws Exception {
Class<?> clazz = Class.forName("ServiceImpl");
Method method = clazz.getDeclaredMethod("MethodA");
method.setAccessible(true);
Object target = ReflectionUtil.getTarget(serviceImpl);
// 注意,这里不能直接用serviceImpl,因为它已经被spring管理,
// 变成serviceImpl真实实例的代理类,而代理类中并没有私有方法,所以需要先获取它的真实实例
method.invoke(target);
}
}
获取spring 代理对象的真实实例的工具类
适用于两种动态代理情况:jdk和cglib
public class ReflectionUtil {
/**
* 获取spring 代理对象的真实实例
* @param proxy 代理对象
* @return
* @throws Exception
*/
public static Object getTarget(Object proxy) throws Exception {
if(!AopUtils.isAopProxy(proxy)) {
return proxy;//不是代理对象
}
if(AopUtils.isJdkDynamicProxy(proxy)) {
return getJdkDynamicProxyTargetObject(proxy);
} else { //cglib
return getCglibProxyTargetObject(proxy);
}
}
private static Object getCglibProxyTargetObject(Object proxy) throws Exception {
Field h = proxy.getClass().getDeclaredField("CGLIB$CALLBACK_0");
h.setAccessible(true);
Object dynamicAdvisedInterceptor = h.get(proxy);
Field advised = dynamicAdvisedInterceptor.getClass().getDeclaredField("advised");
advised.setAccessible(true);
Object target = ((AdvisedSupport)advised.get(dynamicAdvisedInterceptor)).getTargetSource().getTarget();
return target;
}
private static Object getJdkDynamicProxyTargetObject(Object proxy) throws Exception {
Field h = proxy.getClass().getSuperclass().getDeclaredField("h");
h.setAccessible(true);
AopProxy aopProxy = (AopProxy) h.get(proxy);
Field advised = aopProxy.getClass().getDeclaredField("advised");
advised.setAccessible(true);
Object target = ((AdvisedSupport)advised.get(aopProxy)).getTargetSource().getTarget();
return target;
}
}