com.googlecode.mjorm.ObjectDescriptorRegistry Maven / Gradle / Ivy
package com.googlecode.mjorm;
import java.lang.reflect.Type;
import java.util.Collections;
import java.util.HashMap;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
/**
* A registry for {@link ObjectDescriptor}s.
*/
public class ObjectDescriptorRegistry {
private Map, ObjectDescriptor> descriptors
= new HashMap, ObjectDescriptor>();
/**
* Registers an {@link ObjectDescriptor}.
* @param descriptor the {@link ObjectDescriptor}
*/
public void registerDescriptor(ObjectDescriptor descriptor) {
if (descriptors.containsKey(descriptor.getType())) {
throw new IllegalStateException(
"ObjectDescriptor for "+descriptor.getType().getName()+" exists");
}
descriptors.put(descriptor.getType(), descriptor);
}
/**
* @param clazz the clazz
* @return
*/
public boolean hasDescriptor(Class clazz) {
return descriptors.containsKey(clazz);
}
/**
* @param type the type
* @return
*/
public boolean hasDescriptor(Type type) {
if (Class.class.isInstance(type)) {
return hasDescriptor(Class.class.cast(type));
}
return false;
}
/**
* @param clazz the clazz
* @return
*/
public ObjectDescriptor getDescriptor(Class clazz) {
return descriptors.get(clazz);
}
/**
* @param type the type
* @return
*/
public ObjectDescriptor getDescriptor(Type type) {
if (Class.class.isInstance(type)) {
return getDescriptor(Class.class.cast(type));
}
return null;
}
/**
* Returns a {@link List} of {@link ObjectDescriptor}s that describe
* how to map to and from the given type and it's class hieararchy.
* @param type the type
* @return the {@link List}
*/
public LinkedList getDescriptorsForType(Type type) {
List hierarchy = getClassHierarchy(type);
LinkedList ret = new LinkedList();
for (Type clazz : hierarchy) {
ObjectDescriptor desc = getDescriptor(clazz);
if (desc!=null) {
ret.add(desc);
}
}
return ret;
}
/**
* Returns a classes' hierarchy in superclass to subclass order.
* @param type the type
* @return the hierarchy.
*/
private LinkedList getClassHierarchy(Type type) {
LinkedList ret = new LinkedList();
while (type!=null && !Object.class.equals(type)) {
ret.add(type);
if (Class.class.isInstance(type)) {
type = Class.class.cast(type).getSuperclass();
}
}
Collections.reverse(ret);
return ret;
}
}