Google guice inject a instance created by Spring and method intercept - aop

Question

I use Gucie 3.0 to intercept any methods that have my defined annotation #LogRequired. However for my application, some beans are initialized by Spring with injected fields values. After calling giuce injector.injectMembers(this), the beans gets proxied by guice but all original fields values are gone. Looks like Guice re-constucts the beans and throw away all old values. Is this expected behavior or how can I solve this issue?
Create a class extends AbstractModule
public class InterceptorModule extends AbstractModule{ public void configure()
{ LogInterceptor tracing = new LogInterceptor(); requestInjection(tracing); bindInterceptor(Matchers.any(), Matchers.annotatedWith(LogRequired.class), tracing); }
}
Define the interceptor business logic
public class LogInterceptor implements MethodInterceptor { //business logic here }
Create LogService class
Public class LogService { Injector injector = Guice.createInjector(new InterceptorModule()); }
I have one of the bean example below with the getName method wants to be intercepted:
public class UserImplTwo implements IUser {
private String name;
#LogRequired
public String getName() {
return this.name;
}
public void setName(String name) {
this.name = name;
}
}
which is initialized by Spring context:
Finally I have a consumer to consume the bean:
public class Consumer
{
#Inject
private UserImplTwo instance;
public void setInstance(UserImplTwo instance)
{
this.instance = instance;
}
public void init()
{
// the value of name is printed out as 'hello world'
System.out.println( this.instance.getName());
LogService.injector.injectMembers(this);
// the value of name is printed out as null, should be 'hello world'
System.out.println( this.instance.getName());
}
}
Then use Spring to initialized the bean:
<bean id="consumer" class="com.demo.Consumer" init-method="init">
<property name="instance" ref="userTwo"></property>
</bean>
Please let me know if this the the right approach or if I did something wrong, because I have to use Spring to initialize some beans.

Answer 1

A "right approach" is probably to keep things simple and use Spring's DI if you use Spring Framework, and not try to mix and match with Guice :-)
Having said that there seems no technical reason why they can't be mixed and matched together to some degree.
I think you will have more success with another approach. One that I have used before is to make use of Spring MVC Java-based configuration. Here is the basic approach.
Create a class that extends WebMvcConfigurationSupport:
#Configuration
#Import(BeansConfig.class)
public class Config extends WebMvcConfigurationSupport {
}
Separate out your beans config (probably it can be merged with the above but I guess it's quite dull code and you normally don't want want to see it). And use it to create your beans with your Guice injector before providing them to Spring.
#Configuration
public class BeansConfig {
#Bean
public Consumer getConsumer() {
return SomeGuiceInjectorFactory.newInstance(Consumer.class);
}
}
Include this in your spring.xml (or bootstrap other ways if your servlet container is newer than mine was)
<context:annotation-config/>
<bean id="extendedWebMvcConfig" class="Config"/>
Constructor injection and most/all? other Guice goodness should work also with such scenario.
Also you won't need to configure your beans in xml.