Now added support for ProvidedInterfaces in Container.

[utils] / system / general / src / main / java / org / wamblee / system / core / Container.java

diff --git a/system/general/src/main/java/org/wamblee/system/core/Container.java b/system/general/src/main/java/org/wamblee/system/core/Container.java
index a0130f7cf3420094198d72b616f3b281a1973987..d117da95462055d1bfe2a0d703cc1e4551805be2 100644 (file)
--- a/system/general/src/main/java/org/wamblee/system/core/Container.java
+++ b/system/general/src/main/java/org/wamblee/system/core/Container.java
@@ -185,38 +185,42 @@ public class Container extends AbstractComponent<Scope> {
     }
 
     private void validateProvidedInterfacesArePresent() {
-        List<ProvidedInterface> provided = new ArrayList<ProvidedInterface>();
-        for (Component component : _components) {
-            provided.addAll(Arrays.asList(component.getProvidedInterfaces()));
-        }
         for (ProvidedInterface service : getProvidedInterfaces()) {
-            // TODO provided interfaces by components could be
-            // provide subclasses or implementations of the
-            // provided interfaces of the container.
-            // The code below assumes an exact match.
-            if (!(provided.contains(service))) {
-                throw new SystemAssemblyException(getName() + ": Service '"
-                        + service
-                        + "' is not provided by any of its components");
-            }
+            findProvidedInterface(service);
         }
     }
-
+    
     /**
-     * Starts the container. After the container is started, the container
-     * becomes sealed meaning that no further components, required or provided
-     * interfaces may be added.
-     * 
-     * @return Scope.
+     * Finds the component and provided interface that matches a provided interface of this 
+     * container. 
+     * @param aProvided Interface to provide externally. 
+     * @return Pair of component and provided interface
+     * @throws SystemAssemblyException In case there are multiple matches or no match at all.  
      */
-    public Scope start() {
-        checkSealed();
-        validate();
-        Scope scope = super.start(new DefaultScope(new ProvidedInterface[0]));
-        seal();
-        return scope;
+    private Pair<Component,ProvidedInterface> findProvidedInterface(ProvidedInterface aProvided) {
+        List<Pair<Component,ProvidedInterface>> result = 
+            new ArrayList<Pair<Component,ProvidedInterface>>(); 
+        for (Component component: _components) { 
+            for (ProvidedInterface provided: component.getProvidedInterfaces()) { 
+                if ( aProvided.equals(provided) ) { 
+                    result.add(new Pair<Component,ProvidedInterface>(component, provided));   
+                }
+            }
+        }
+        if ( result.size() == 0) { 
+            throw new SystemAssemblyException(getQualifiedName() + ": Service '"
+                    + aProvided
+                    + "' is not provided by any of its components");
+        }
+        if ( result.size() > 1) { 
+            throw new SystemAssemblyException(getQualifiedName() + ": Service '"
+                    + aProvided
+                    + "' is provided by multiple components: " + result);
+        }
+        return result.get(0);
     }
 
+    
     /**
      * Seal the container, meaning that no further components or interfaces may
      * be added.
@@ -233,16 +237,38 @@ public class Container extends AbstractComponent<Scope> {
     public boolean isSealed() {
         return _sealed;
     }
+    
+    /**
+     * Utility method to start with an empty external scope. This is useful for
+     * top-level containers which are not part of another container. 
+     * @return Scope. 
+     */
+    public Scope start() {
+        Scope scope = new DefaultScope(getProvidedInterfaces()); 
+        return super.start(scope);
+    }
 
     @Override
     protected Scope doStart(Scope aExternalScope) {
-        return doStartOptionalDryRun(aExternalScope, false);
+        checkSealed();
+        validate();
+        Scope scope = new DefaultScope(getProvidedInterfaces(), aExternalScope);
+        doStartOptionalDryRun(scope, false);
+        exposeProvidedInterfaces(aExternalScope, scope);
+        seal();
+        return scope;
     }
 
-    private Scope doStartOptionalDryRun(Scope aExternalScope, boolean aDryRun) {
-        LOG.info("Starting '" + getQualifiedName() + "'");
+    private void exposeProvidedInterfaces(Scope aExternalScope, Scope aInternalScope) {
+        for (ProvidedInterface intf: getProvidedInterfaces()) { 
+            Pair<Component, ProvidedInterface> found = findProvidedInterface(intf);
+            Object svc = aInternalScope.getInterfaceImplementation(found.getSecond(), Object.class);
+            addInterface(intf, svc, aExternalScope);
+        }
+    }
 
-        Scope scope = new DefaultScope(getProvidedInterfaces(), aExternalScope);
+    private void doStartOptionalDryRun(Scope aScope, boolean aDryRun) {
+        LOG.info("Starting '" + getQualifiedName() + "'");
 
         List<Pair<ProvidedInterface,Component>> allProvided = new ArrayList<Pair<ProvidedInterface,Component>>();
         
@@ -256,8 +282,8 @@ public class Container extends AbstractComponent<Scope> {
 
                 // Start the service.
                 if (!aDryRun) {
-                    Object runtime = component.start(scope);
-                    scope.addRuntime(component, runtime);
+                    Object runtime = component.start(aScope);
+                    aScope.addRuntime(component, runtime);
                     started.add(component);
                 }
 
@@ -272,11 +298,10 @@ public class Container extends AbstractComponent<Scope> {
             } catch (RuntimeException e) {
                 LOG.error(getQualifiedName() + ": could not start '"
                         + component.getQualifiedName() + "'", e);
-                stopAlreadyStartedComponents(started, scope);
+                stopAlreadyStartedComponents(started, aScope);
                 throw e;
             }
         }
-        return scope;
     }
 
     private void addProvidersOfRequiredInterfaces(