如何将非Spring客户端与基于Spring的jar的配置脱钩？

Question

I have only limited experience with Spring but am working with someone who really likes it. We've built a set of packages that use Spring heavily and now we need to provide an access layer that exposes that functionality to clients that may not use Spring.

My primary goal is that clients of the access layer should not be required to configure Spring in order to use it. Obviously Spring will be on the deployment classpath. In an ideal world, the client could build against the access layer package and deploy without knowing that Spring is being used. Is this possible? (No, using a remote service is not an option.)

Answer 1

As you don't want to have to write a load of new code that essentially wires up your application the same way spring already does it, is it possible you could hide all of this behind some sort of "facade" class that you will give to your client?

For example, say I had a spring context that sets up ServiceA and ServiceB (these are the services that the client wants to access)

I could write some classes like this...

public interface ClientServiceFacade {
    ServiceA getServiceA();

    ServiceB getServiceB();

    void shutdown();
}

public class ClientServiceFacadeFactory {
    public static ClientServiceFacade create() {
        return new ClientServiceFacadeImpl();
    }
}

public class ClientServiceFacadeImpl implements ClientServiceFacade {
    private static final CONTEXT_LOCATION = "classpath:spring/context.xml";

    private ClassPathXmlApplicationContext context;

    public ClientServiceFacadeImpl() {
        context = new ClassPathXmlApplicationContext(CONTEXT_LOCATION);
    }

    @Override
    public ServiceA getServiceA() {
        return context.getBean(ServiceA.class);
    }

    @Override
    public ServiceB getServiceB() {
        return context.getBean(ServiceB.class);
    }

    @Override
    public void shutdown() {
        context.close();
    }
}

Your clients will still have to include the spring JAR as a dependency, but (apart form that) they would have no idea that Spring is being used in the background.

Answer 2

如何在静态块或静态init方法（如果要从外部触发）上初始化Spring上下文，或在守护进程线程上启动呢？