(详细)Hibernate查询技术（Query、Session、Criteria），Hibernate的三种状态，Hibernate集合struts2实现登录功能（二）

一、Hibernate的三种查询方式（掌握）

org.hibernate.LazyInitializationException: could not initialize proxy - no Session

1.1、Query查询（重点）

public void doRemove(Integer id) throws Exception {
		// 注意,使用Hibernate删除时,必须先查询对象,再删除.
		// HibernateSessionFactory.getSession().delete(findById(id));
		String hql = "DELETE FROM News AS n WHERE n.id = ?" ;
		Query query = HibernateSessionFactory.getSession().createQuery(hql);
		query.setInteger(0, id);
		query.executeUpdate();
	}

public void doUpdate(News vo) throws Exception {
		// HibernateSessionFactory.getSession().update(vo);
		String hql = "UPDATE News AS n SET n.title = ?,n.content = ? WHERE n.id = ?" ;
		Query query = HibernateSessionFactory.getSession().createQuery(hql);
		query.setString(0, vo.getTitle());
		// ....其他参数一样设置
		query.executeUpdate();
	}

public List testHQL() throws Exception {
		String hql = "SELECT n.id,n.title FROM News AS n";
		Query query = HibernateSessionFactory.getSession().createQuery(hql);
		return query.list();
	}

public void testHQL() throws Exception {
		List all = ServiceFactory.getINewsServiceInstance().testHQL();
		Object[] value1 = (Object[]) all.get(0);
		System.out.println(value1[1]);
	}

public List testHQL() throws Exception {
		String hql = "SELECT n.id AS id,n.title AS title FROM News AS n";
		Query query = HibernateSessionFactory.getSession().createQuery(hql);
		query
				.setResultTransformer(new AliasToBeanResultTransformer(
						News.class));
		return query.list();
	}

<query name="findAll">
		FROM News AS n WHERE n.title LIKE ?
	</query>

Query query = HibernateSessionFactory.getSession().getNamedQuery(
				"findAll");
		query.setString(0, "%测试%");
		return query.list();

1.2、Criteria查询（了解）

public List<News> testCriteria() throws Exception {
		// 根据传入的pojo类型,查询该类型对应的全部数据
		Criteria c = HibernateSessionFactory.getSession().createCriteria(
				News.class);		
		return c.list();
	}

public List<News> testCriteria() throws Exception {
		// 根据传入的pojo类型,查询该类型对应的全部数据
		Criteria c = HibernateSessionFactory.getSession().createCriteria(
				News.class);
		// 1、WHERE id = 26
		// c.add(Restrictions.eq("id", 26));
		// 2、WHERE id > 26
		// c.add(Restrictions.gt("id", 26));
		// 3、WHERE id < 26
		// c.add(Restrictions.lt("id", 26));
		// 4、WHERE id >= 26
		// c.add(Restrictions.ge("id", 26));
		// 5、WHERE id <= 26
		// c.add(Restrictions.le("id", 26));
		// 6、WHERE id <> 26
		// c.add(Restrictions.ne("id", 26));
		// 7、WHERE title LIKE '%测试%'
		// c.add(Restrictions.like("title", "%测试%"));
		// 8、WHERE id between 23 and 27
		// c.add(Restrictions.between("id", 23, 27));
		// 9、WHERE id IN (23,25,27)
		// List<Integer> allIds = new ArrayList<Integer>();
		// allIds.add(23);
		// allIds.add(25);
		// allIds.add(27);
		// c.add(Restrictions.in("id", allIds));
		// 10、复杂条件，需要使用and或or来连接各个条件
		// WHERE id = 23 OR (id <> 26 AND title LIKE '%测试%')
		c
				.add(Restrictions.or(Restrictions.eq("id", 23), Restrictions
						.and(Restrictions.ne("id", 26), Restrictions.like(
								"title", "%测试%"))));
		return c.list();
	}

c.addOrder(Order.desc("id"));

ProjectionList pro = Projections.projectionList();
		// 加入统计函数
		pro.add(Projections.rowCount());
		// 还可以加入分组条件
		pro.add(Projections.groupProperty("title"));
		c.setProjection(pro);

二、Hibernate中Session操作的三种状态

三、Struts2 + Hibernate实现用户登陆功能

CREATE TABLE T_User (
       userid         varchar2(40)        primary key , 
       real_name      varchar2(20)        not null,
       password       varchar2(32)        not null,
       regist_date    date                default sysdate,
       last_login_date         date                           
);

INSERT INTO t_USER (userid,real_name,password) 
VALUES ('zhangsan','张三','123');

commit;

public class TUserDAOImpl implements ITUserDAO {
	public boolean isLogin(TUser user) throws Exception {
		String hql = "FROM TUser AS u WHERE u.userid = ? AND u.password = ?";
		Query query = HibernateSessionFactory.getSession().createQuery(hql);
		query.setString(0, user.getUserid());
		query.setString(1, user.getPassword());
		List<User> allUser = query.list();
		if (allUser != null && allUser.size() > 0) {
			// 登陆成功
			// 取得查询的结果
			TUser result = (TUser) allUser.get(0);
			// 根据引用传递,将值设置到传入的user中
			user.setRealName(result.getRealName());
			user.setRegistDate(result.getRegistDate());
			user.setLastLoginDate(result.getLastLoginDate());
			return true;
		}
		return false;
	}
}

<%@ taglib uri="/struts-tags" prefix="s"%>

<center>
			<form action="tuser!login.action" method="post">
				用户名：<input type="text" name="tuser.userid"/> <br/>
				密码：<input type="password" name="tuser.password"/> <br/>
				<input type="submit" value="提交" /> 
			</form>
		//下面的为struts标签
			<s:form action="tuser!login" namespace="/" method="post" theme="simple">
				用户名：<s:textfield name="tuser.userid"></s:textfield> <br/>
				密码：<s:password name="tuser.password"></s:password> <br/>
				<s:submit value="提交"></s:submit>
			</s:form>
		</center>

public class TUserAction extends ActionSupport {
	private TUser tuser;
	public TUser getTuser() {
		return tuser;
	}
	public void setTuser(TUser tuser) {
		this.tuser = tuser;
	}

	public String login() throws Exception {
		boolean flag = ServiceFactory.getITUserServiceInstance().login(tuser);

		// 根据结果,决定跳转的位置
		if (flag) {
			// 将用户保存到session属性范围中
			ServletActionContext.getRequest().getSession().setAttribute("user",
					tuser);
			return "suc";
		}
		// 添加错误信息,页面使用标签显示
		super.addActionError("用户名或密码错误,请重新输入!");
		return "input";
	}
}

<struts>
	<package name="root" namespace="/" extends="struts-default">
		<action name="tuser" class="org.liky.login.action.TUserAction">
			<result name="suc">/pages/suc.jsp</result>
			<result name="input">/index.jsp</result>
		</action>
	</package>
</struts>

<center>
			用户登陆成功,当前登陆用户为: ${user.userid} 
		</center>

<font color="red">
			<s:actionerror/>
		</font>