employeedaoimpl.java

用JSF1.2和EJB3.0实现的一个项目实例

package org.qiujy.ejb3.dao.impl;

import java.util.List;

import javax.ejb.Local;
import javax.ejb.Remote;
import javax.ejb.Stateless;
import javax.persistence.EntityManager;
import javax.persistence.PersistenceContext;

import org.qiujy.ejb3.dao.EmployeeDao;
import org.qiujy.ejb3.entity.Employee;

/**
 * 员工DAO实现类--无状态会话Bean
 * @author qiujy
 * @version 1.0
 */
@Stateless
@Local(EmployeeDao.class)
@Remote(EmployeeDao.class)
public class EmployeeDaoImpl implements EmployeeDao {
	
	/** 持久化实例管理器类--由EJB容器动态注入 */
	@PersistenceContext
	private EntityManager em;

	public void delete(Employee employee) {
		Employee empl = em.merge(employee);
		em.remove(empl);
	}

	@SuppressWarnings("unchecked")
	public List<Employee> findAllEmployees() {
		return (List<Employee>) em.createQuery("select empl from Employee empl")
								  .getResultList();
	}

	public Employee findEmployee(Integer id) {
		return (Employee) em.find(Employee.class, id);
	}

	public void persist(Employee employee) {
		em.persist(employee);
	}

	public void update(Employee employee) {
		em.merge(employee);
	}

}