Package rename org.wamblee.system to org.wamblee.system.core

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

diff --git a/system/general/src/main/java/org/wamblee/system/core/DefaultRequiredInterface.java b/system/general/src/main/java/org/wamblee/system/core/DefaultRequiredInterface.java
new file mode 100644 (file)
index 0000000..32276a2
--- /dev/null
+++ b/system/general/src/main/java/org/wamblee/system/core/DefaultRequiredInterface.java
@@ -0,0 +1,121 @@
+/*
+ * Copyright 2007 the original author or authors.
+ * 
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * 
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */ 
+package org.wamblee.system.core;
+
+import java.util.Arrays;
+
+public class DefaultRequiredInterface implements RequiredInterface {
+
+       private String _name;
+       private Class[] _required;
+       private ProvidedInterface _provider; 
+       
+       public DefaultRequiredInterface(String aName, Class aInterface) {
+               this(aName, new Class[] { aInterface }); 
+       }
+
+       public DefaultRequiredInterface(String aName, Class[] aInterfaces) {
+               _name = aName; 
+               _required = aInterfaces; 
+       }
+
+       @Override
+       public String getName() {
+               return _name;
+       }
+       
+       @Override
+       public boolean implementedBy(ProvidedInterface aDescriptor) {
+               Class[] provided = aDescriptor.getInterfaceTypes();
+               for (Class required : _required) {
+                       if ( !serviceProvided(required, provided)) { 
+                               return false; 
+                       }
+               }
+               // all required interfaces are provided.
+               return true; 
+       }
+       
+       /**
+        * Check if the required interface is implemented by one of the provided interfaces. 
+        * @param aRequired required interface
+        * @param aProvided Provided interfaces.
+        * @return
+        */
+       private boolean serviceProvided(Class aRequired, Class[] aProvided) { 
+               for (Class provided: aProvided) {
+                       try {
+                               provided.asSubclass(aRequired);
+                               return true; 
+                       } catch (ClassCastException e) {
+                               // No match, try the next one.
+                       }
+               }
+               return false; 
+       }
+       
+       @Override
+       public ProvidedInterface getProvider() {
+               return _provider; 
+       }
+       
+       @Override
+       public void setProvider(ProvidedInterface aProvider) {
+               _provider = aProvider;  
+       }
+
+       @Override
+       public <T> T getImplementation(Class<T> aClass) {
+               if ( _provider == null ) { 
+                       return null; 
+               }
+               return (T)_provider.getImplementation();
+       }
+       
+       @Override
+       public boolean equals(Object obj) {
+               if ( !(obj instanceof DefaultRequiredInterface)) { 
+                       return false; 
+               }
+               DefaultRequiredInterface descr = (DefaultRequiredInterface)obj;
+               if ( _required.length != descr._required.length ) { 
+                       return false; 
+               }
+               String[] interfaces1 = new String[_required.length];
+               String[] interfaces2 = new String[_required.length];
+               for (int i = 0; i < _required.length; i++) {  
+                       interfaces1[i] = _required[i].getName();
+                       interfaces2[i] = descr._required[i].getName();
+               }
+               Arrays.sort(interfaces1);
+               Arrays.sort(interfaces2);
+               return Arrays.equals(interfaces1, interfaces2);
+       }
+
+       @Override
+       public int hashCode() {
+               return _required.hashCode(); 
+       }
+       
+       @Override
+       public String toString() {
+               StringBuffer buf = new StringBuffer();
+               for (Class intf: _required) { 
+                       buf.append("." + intf.getName());
+               }
+               return buf.toString();
+       }
+}