ecf 분석 - Container

//host.rs start과정

public void start(BundleContext context) throws Exception {

this.context = context;

// 1. Create R-OSGi Container

IContainerManager containerManager = getContainerManagerService();

container = containerManager.getContainerFactory().createContainer(

"ecf.r_osgi.peer");

// 2. Get remote service container adapter
//이놈이 Proxy.newInstance()로 생성되는 객체.... 

IRemoteServiceContainerAdapter containerAdapter = (IRemoteServiceContainerAdapter) container

.getAdapter(IRemoteServiceContainerAdapter.class);

// 3. Lookup IRemoteServiceReference

                // Proxy 객체를 이용해서 interface를 가져오네.... containerAdapter가 proxy.invokeObject
//그런데, getRemoteServiceReferences를 구현한 클래스를 찾을 수 없다... 어떻게 구현한걸까? 

IRemoteServiceReference[] helloReferences = containerAdapter

.getRemoteServiceReferences(IDFactory.getDefault().createID(

container.getConnectNamespace(), ROSGI_SERVICE_HOST),

IHello.class.getName(), null);

Assert.isNotNull(helloReferences);

Assert.isTrue(helloReferences.length > 0);

// 4. Get remote service for reference

IRemoteService remoteService = containerAdapter

.getRemoteService(helloReferences[0]);

// 5. Get the proxy

IHello proxy = (IHello) remoteService.getProxy();

// 6. Finally...call the proxy

proxy.hello("RemoteService Consumer");

// Call asynchronously via listener

callViaListener(remoteService);

}

r-osgi에서는 local마다 container를 통해 서로 통신을 하게 된다.
container는 containerFactory에서 얻을 수 있으며, factory패턴을 이용해서 container를 가져온다.

createContainer는 여러가지로 오버로딩되어있으며, String, ID, ContainerType 객체를 파라미터로 받아 container를 생성한다.
예제에서는 String을 파라미터로 넘겨서 생성한다. 그 함수의 내용은

public IContainer createContainer(String containerTypeDescriptionName) throws ContainerCreateException {

return createContainer(getDescriptionByNameWithException(containerTypeDescriptionName), (Object[]) null);

} 

다시 createrContainer를 호출함. 모든 createContainer는
 public IContainer createContainer(ContainerTypeDescription containerTypeDescription, Object[] parameters) throws ContainerCreateException; 이를 호출하게 되어있다.

public IContainer createContainer(ContainerTypeDescription containerTypeDescription, Object[] parameters) throws ContainerCreateException {

String method = "createContainer"; //$NON-NLS-1$

Trace.entering(ECFPlugin.PLUGIN_ID, ECFDebugOptions.METHODS_ENTERING, ContainerFactory.class, method, new Object[] {containerTypeDescription, Trace.getArgumentsString(parameters)});

if (containerTypeDescription == null)

throwContainerCreateException("ContainerTypeDescription cannot be null", null, method); //$NON-NLS-1$
//객체를 그냥 써도 되는데, 왜 함수를 호출해서 다시 결과를 받는가? containerTypes을 동기화를 걸어서 한순간에 하나의 스레드만 가져오게 하려고, 

ContainerTypeDescription cd = getDescription0(containerTypeDescription);

if (cd == null)

throwContainerCreateException("ContainerTypeDescription '" //$NON-NLS-1$

+ containerTypeDescription.getName() + "' not found", null, method); //$NON-NLS-1$

IContainerInstantiator instantiator = null;

try {

instantiator = cd.getInstantiator();

} catch (Exception e) {

throwContainerCreateException("createContainer cannot get IContainerInstantiator for description : " //$NON-NLS-1$

+ containerTypeDescription, e, method);

}

// Ask instantiator to actually create instance

IContainer container = instantiator.createInstance(containerTypeDescription, parameters);

if (container == null)

throwContainerCreateException("Instantiator returned null for '" //$NON-NLS-1$

+ cd.getName() + "'", null, method); //$NON-NLS-1$

// Add to containers map if container.getID() provides a valid value.

ID containerID = container.getID();

if (containerID != null)

addContainer(container, cd);

Trace.exiting(ECFPlugin.PLUGIN_ID, ECFDebugOptions.METHODS_EXITING, ContainerFactory.class, method, container);

return container;

}


//container의 getAdapter
//serviceType이 이 클래스 객체로 형변환 될 수 있으면 이 객체를 리턴.

public Object getAdapter(Class serviceType) {

if (serviceType == null)

return null;

if (serviceType.isInstance(this)) {

return this;

}

ECFPlugin plugin = ECFPlugin.getDefault();

if (plugin == null)

return null;

IAdapterManager adapterManager = plugin.getAdapterManager();

return (adapterManager == null) ? null : adapterManager.loadAdapter(this, serviceType.getName());

}