我有以下课程:
public FooDAO extends AbstractDAO<Foo> { // Dropwizard DAO
@Inject FooDAO(SessionFactory sf) { super(sf); }
public void foo() { /* use SessionFactory */ }
}
public class FooService {
private final FooDAO fooDAO; // Constructor-injected dependency
@Inject FooService (FooDAO fooDAO) { this.fooDAO = fooDAO; }
@UnitOfWork
public void foo() {
this.fooDAO.foo();
System.out.println("I went through FooService.foo()");
}
}
Now, FooService
不是资源,因此 Dropwizard 不知道它,也不会自动代理它。然而,Dropwizard 的聪明人做到了,这样我就可以通过它获得代理UnitOfWorkAwareProxyFactory
.
我尝试使用拦截器将这些代理提供给 Guice,但我遇到了一个问题,因为UnitOfWorkAwareProxyFactory
只创建新实例,从不让我传递现有对象。新实例的问题是我不知道要给它的参数,因为它们是由 Guice 注入的。
我如何创建@UnitOfWork
- 现有对象的感知代理?
这是我迄今为止制作的拦截器:
public class UnitOfWorkModule extends AbstractModule {
@Override protected void configure() {
UnitOfWorkInterceptor interceptor = new UnitOfWorkInterceptor();
bindInterceptor(Matchers.any(), Matchers.annotatedWith(UnitOfWork.class), interceptor);
requestInjection(interceptor);
}
private static class UnitOfWorkInterceptor implements MethodInterceptor {
@Inject UnitOfWorkAwareProxyFactory proxyFactory;
Map<Object, Object> proxies = new IdentityHashMap<>();
@Override public Object invoke(MethodInvocation mi) throws Throwable {
Object target = proxies.computeIfAbsent(mi.getThis(), x -> createProxy(mi));
Method method = mi.getMethod();
Object[] arguments = mi.getArguments();
return method.invoke(target, arguments);
}
Object createProxy(MethodInvocation mi) {
// here, what to do? proxyFactory will only provide objects where I pass constructor arguments, but... I don't have those!
}
}
}
当然,如果 Dropwizard(或 Guice)为我提供了一种更简单的方法,那么它是什么呢?