package org.spring4gwt.examples.simplerpc.server.servlet;

import javax.persistence.EntityManager;

import org.spring4gwt.examples.simplerpc.shared.dto.HasVersionAndId;
import org.springframework.beans.factory.annotation.Autowired;

import com.google.web.bindery.requestfactory.shared.Locator;

public class GWTSpringEntityLocator<T extends HasVersionAndId> extends
		Locator<T, Long> {
	@Autowired
	EntityManager entityManager;

	@Override
	public T create(Class<? extends T> clazz) {
		try {
			return clazz.newInstance();
		} catch (InstantiationException e) {
			throw new RuntimeException(e);
		} catch (IllegalAccessException e) {
			throw new RuntimeException(e);
		}
	}

	@Override
	public T find(Class<? extends T> clazz, Long id) {
		return entityManager.find(clazz, id);
	}

	@Override
	public Class<T> getDomainType() {
		// Unused, and if it becomes used, we're in trouble
		throw new UnsupportedOperationException();
	}

	@Override
	public Long getId(T domainObject) {
		return domainObject.getId();
	}

	@Override
	public Class<Long> getIdType() {
		return Long.class;
	}

	@Override
	public Object getVersion(T domainObject) {
		return domainObject.getVersion();
	}
}