jtulach@75: 
jtulach@75: package api;
jtulach@75: 
jtulach@75: // BEGIN: instanceof.class.InstanceProvider2
jtulach@210: 
jtulach@210: import java.util.Arrays;
jtulach@210: import java.util.HashSet;
jtulach@210: import java.util.Set;
jtulach@210: import java.util.concurrent.Callable;
jtulach@210: 
jtulach@209: public final class InstanceProvider {
jtulach@210:     private final Callable<Object> instance;
jtulach@210:     private final Set<String> types;
jtulach@191: 
jtulach@210:     public InstanceProvider(Callable<Object> instance) {
jtulach@75:         this.instance = instance;
jtulach@210:         this.types = null;
jtulach@210:     }
jtulach@210:     /** Specifies not only a factory for creating objects, but
jtulach@210:      * also additional information about them.
jtulach@210:      * @param instance the factory to create the object
jtulach@210:      * @param type the class that the create object will be instance of
jtulach@210:      * @since 2.0 
jtulach@210:      */
jtulach@210:     public InstanceProvider(Callable<Object> instance, String... types) {
jtulach@210:         this.instance = instance;
jtulach@210:         this.types = new HashSet<String>();
jtulach@210:         this.types.addAll(Arrays.asList(types));
jtulach@75:     }
jtulach@75:     
jtulach@210:     public Class<?> instanceClass() throws Exception {
jtulach@210:         return instance.call().getClass();
jtulach@75:     }
jtulach@210:     public Object instanceCreate() throws Exception {
jtulach@210:         return instance.call();
jtulach@75:     }
jtulach@75:     
jtulach@210:     /** Allows to find out if the InstanceProvider creates object of given
jtulach@210:      * type. This check can be done without loading the actual object or
jtulach@210:      * its implementation class into memory.
jtulach@210:      * 
jtulach@210:      * @param c class to test 
jtulach@210:      * @return if the instances produced by this provider is instance of c
jtulach@210:      * @since 2.0 
jtulach@210:      */
jtulach@210:     public boolean isInstanceOf(Class<?> c) throws Exception {
jtulach@210:         if (types != null) {
jtulach@210:             return types.contains(c.getName());
jtulach@75:         } else {
jtulach@75:             // fallback
jtulach@75:             return c.isAssignableFrom(instanceClass());
jtulach@75:         }
jtulach@75:     }
jtulach@75: 
jtulach@75:     
jtulach@75: }
jtulach@75: // END: instanceof.class.InstanceProvider2