roledao.java

来自「struts2 spring2.5 jpa hibernate 权限管理系统源代」· Java 代码 · 共 81 行

package sunyang.role.dao;

import java.util.List;

import javax.persistence.*;

import sunyang.persistence.EntityManagerHelper;
import sunyang.role.domain.Role;

public class RoleDAO implements IRoleDAO {
	// 声明静态常量
	public static final String ROLENAME = "rolename";

	// 得到实体管理器
	private EntityManager getEntityManager() {
		return EntityManagerHelper.getEntityManager();
	}

	// 新增数据
	public void save(Role entity) {
		try {
			EntityManagerHelper.beginTransaction();
			getEntityManager().persist(entity);
			EntityManagerHelper.commit();
		} catch (RuntimeException re) {
			EntityManagerHelper.rollback();
			throw re;
		}
	}

	// 删除数据
	public void delete(Role entity) {
		try {
			EntityManagerHelper.beginTransaction();
			entity = getEntityManager()
					.getReference(Role.class, entity.getId());
			getEntityManager().remove(entity);
			EntityManagerHelper.commit();
		} catch (RuntimeException re) {
			EntityManagerHelper.rollback();
			throw re;
		}
	}

	// 修改数据
	public Role update(Role entity) {
		try {
			EntityManagerHelper.beginTransaction();
			Role result = getEntityManager().merge(entity);
			EntityManagerHelper.commit();
			return result;
		} catch (RuntimeException re) {
			EntityManagerHelper.rollback();
			throw re;
		}
	}

	// 通过id查询数据
	public Role findById(Integer id) {
		try {
			Role instance = getEntityManager().find(Role.class, id);
			return instance;
		} catch (RuntimeException re) {
			throw re;
		}
	}

	// 查询所有数据
	@SuppressWarnings("unchecked")
	public List<Role> findAll() {
		try {
			final String queryString = "select model from Role model";
			Query query = getEntityManager().createQuery(queryString).setHint(
					"toplink.refresh", true);
			return query.getResultList();
		} catch (RuntimeException re) {
			throw re;
		}
	}

}