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  • Hibernate（三）

    ================================HQL=========================
    HQL:Hibernate Query Language
        from Dept(类名)
    范例：Dept类名
        1.select dept from Dept as dept
        2.from Dept where deptName = 'SALES'
        
        3.from Dept dept where dept.location is not null
            dept对象.对象的属性location
        
        4.from Emp order by hireDate，salary desc

    步骤：
        1.获取Session对象；
        2.编写HQL语句；
        3.创建Query对象；
        4.执行查询，得到查询结果。
            a.list()
            b.iterate() 先查询id，再执行查询其他（执行n+1次）
        
    JDBC步骤：
        1.获取JDBC对象；
        2.编写SQL语句；（Structure Query Language）
        3.创建PreparedStatement对象；
        4.执行查询，得到查询结果。

    查询语句中绑定参数:
        String hql = "from User where name ='" + name + "'"; -- 不安全，性能地

        方法：
            a.参数位置绑定
                使用 ? 设置占位符 -- from Dept as dept where dept.deptName = ?

            b.参数名字绑定(实现动态查询:条件最多3个/条件个数不确定)
                使用:name方式设置 -- from Dept as dept where dept.deptName = :name

    实现动态查询：
        1.封装查询条件
        2.动态生成HQL语句
        3.使用setProperties赋值

    范例：

    技巧：

    　　1.转发：/jsp
    　　2.重定向：request.getContextPath()/

    1.dept.jsp
    startup 启动tomcat
    网页是入口，tomcat的main入口

     1 <%-- 引入JSP页面PAGE指令 --%>
 2 <%@ page language="java" contentType="text/html; charset=UTF-8"
 3     pageEncoding="UTF-8"%>
 4 <%-- 引入JSTL标签指令 --%>
 5 <%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
 6 <!DOCTYPE html>
 7 <html language="zh-CN">
 8 <head>
 9     <meta charset="utf-8">
10     <!-- 设置浏览器渲染的引擎  -->
11     <meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1">
12     <!-- 设置支持移动设备  -->
13     <meta name="viewport" content="width=device-width, initial-scale=1">
14     <title>网页标题</title>
15     <!-- 引用bootstrap样式 -->
16     <link rel="stylesheet" type="text/css" href="<%=request.getContextPath() %>/css/bootstrap.min.css">
17 </head>
18 <body>
19     <div class="container-fluid">
20         <div class="panel panel-primary">
21             <div class="panel-heading"><span class="h3">部门信息</span></div>
22             <div class="panel-body">
23                 <form action="<%=request.getContextPath()%>/dept/search?oper=byCondition" method="post">
    　　　　　　　　　　　　　 <label>部门编号</label> 
    　　　　　　　　　　　　　 <input name="deptId" type="text"/>
24                     <label>部门名称</label>
25                     <!-- name与Dept类的属性名一样 -->
26                     <input name="deptName" type="text"/>
27                     <label>部门位置</label>
28                     <input name="location" type="text"/>
29                     <input type="submit" value="搜索" data-toggle="search"/>
30                 </form>
31             </div>
32             
33             <table class="table table-bordered">
34                 <thead>
35                     <tr>
36                         <td>部门编号</td>
37                         <td>部门名称</td>
38                         <td>部门位置</td>
39                         <td>操作</td>
40                     </tr>
41                 </thead>
42                 <tbody>
43                     <c:forEach items="${requestScope.depts }" var="dept">
44                         <tr>
45                             <td>${dept.deptId }</td>
46                             <td>${dept.deptName }</td>
47                             <td>${dept.location }</td>
48                             <td><a class="btn btn-primary btn-xs" href="javascript:;">删除</a></td>
49                         </tr>
50                     
51                     </c:forEach>
52                 </tbody>
53             </table>
54         </div>    
55     </div>
56     
57     <!-- 引用外部JS文件  -->
58     <script type="text/javascript" src="<%=request.getContextPath() %>/js/jquery-2.2.4.js"></script>
59     <script type="text/javascript" src="<%=request.getContextPath() %>/js/bootstrap.min.js"></script>
60 
61     <script type="text/javascript">
62         $(function() {
63             $('[data-toggle="search"]').click(function() {
64                 
65             });
66         });
67     </script>
68 </body>
69 </html>

    2.Dept 类

     1 package com.Elastic.HibernateDemo3.ivy.entity;
 2 
 3 import java.io.Serializable;
 4 import java.util.Set;
 5 
 6 public class Dept implements Serializable {
 7     /**
 8      * <p>
 9      * <h3>作用：</h3>
10      * </p>
11      * @see long
12      * @see serialVersionUID
13      */
14     private static final long serialVersionUID = 2261199233032137882L;
15     private Integer deptId;
16     private String deptName;
17     private String location;
    
29     public Integer getDeptId() {
30         return deptId;
31     }
32     public void setDeptId(Integer deptId) {
33         this.deptId = deptId;
34     }
35     public String getDeptName() {
36         return deptName;
37     }
38     public void setDeptName(String deptName) {
39         this.deptName = deptName;
40     }
41     public String getLocation() {
42         return location;
43     }
44     public void setLocation(String location) {
45         this.location = location;
46     }
47 }

    3.Dept.hbm.xml

     1 <?xml version="1.0" encoding="UTF-8"?>
 2 <!DOCTYPE hibernate-mapping PUBLIC 
 3     "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
 4     "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
 5     
 6 <hibernate-mapping>
 7     <!-- 实体类路径：数据库表名-->
 8     <class name="com.Elastic.HibernateDemo3.ivy.entity.Dept" table="dept">
 9         <!-- 主键OID(唯一标识) -->
10         <id name="deptId" column="deptid"><!-- column单独一行，属性更全 -->
11             <!-- 主键生成策略：increment，assigned，native等 -->
12             <generator class="increment"></generator>
13         </id>
14         
15         <!-- 属性名（★★setDeptName★★）：数据库表字段(如果是关键字，用``标志) -->
16         <property name="deptName" column="deptname"></property>
17         <property name="location" column="location"></property>
18         
19     </class>
20 </hibernate-mapping>

    6.DeptDao 类

    1 package com.Elastic.HibernateDemo3.ivy.dao;
2 
3 import com.Elastic.HibernateDemo3.ivy.entity.Dept;
4 public interface DeptDao extends IBaseDao<Dept>{
5 
6 
7 }

    7.DeptDaoImpl 类

     1 package com.Elastic.HibernateDemo3.ivy.dao.impl;
 2 
 3 import com.Elastic.HibernateDemo3.ivy.dao.BaseDao;
 4 import com.Elastic.HibernateDemo3.ivy.dao.DeptDao;
 5 import com.Elastic.HibernateDemo3.ivy.entity.Dept;
 6 
 7 public class DeptDaoImpl extends BaseDao<Dept> implements DeptDao {
 8 
 9     
10 }

    4.IBaseDao类

     1 package com.Elastic.HibernateDemo3.ivy.dao;
 2 
 3 import java.io.Serializable;
 4 import java.util.List;
 5 import java.util.Map;
 6 public interface IBaseDao<T> {
 7     void save(T record);
 8     
 9     //不明确id的类型，就用Serializable
10     void delete(Serializable id);
11     
12     void update(T record);
13     
14     T findById(Serializable id);
15     
16     List<T> find(Map<String, Object> params);
17     
18     List<T> find(String hql,Map<String, Object> params);
19 }

    5.BaseDao

     1 /**
 2  * 
 3  */
 4 package com.Elastic.HibernateDemo3.ivy.dao;
 5 
 6 import java.io.Serializable;
 7 import java.lang.reflect.ParameterizedType;
 8 import java.util.List;
 9 import java.util.Map;
10 
11 import org.hibernate.Query;
12 import org.hibernate.Session;
13 
14 import com.Elastic.HibernateDemo3.ivy.util.HibernateUtil;
15 //忽略警告
16 @SuppressWarnings({ "rawtypes", "unchecked" })
17 public class BaseDao<T> implements IBaseDao<T>{
18     
19     private Class entityClass;
20     
21     public BaseDao(){
22         entityClass = this.getEntityClass();
23     }
24     
25     /**
26      * 
27      * <p>
28      * <h3>方法功能描述：根据反射得到实体类的类型</h3>
29      * </p>
30      * @return
31      * @procedure 执行过程
32      * @see BaseDao
33      */
34     private Class getEntityClass(){
35         try {
36             ParameterizedType paramsType = (ParameterizedType)this.getClass().getGenericSuperclass();
37             return (Class)paramsType.getActualTypeArguments()[0];
38         } catch (Exception e) {
39             e.printStackTrace();
40         }
41         return null;
42     }
43     
44     public Session getSession(){
45         return HibernateUtil.getSession();
46     }
47     
48     @Override
49     public void save(T record){
50         this.getSession().save(record);
51     }
52     
53     @Override
54     public void delete(Serializable id){
55         this.getSession().delete(this.findById(id));
56     }
57     
58     @Override
59     public void update(T record){
60         this.getSession().update(record);
61     }
62     
63     
64     @Override
65     public T findById(Serializable id){
66         return (T)this.getSession().get(entityClass, id);
67     }
68     
69     @Override
70     public List<T> find(Map<String, Object> params){
71         StringBuffer hql = new StringBuffer("from ");
72         hql.append(entityClass.getName());
73         hql.append(" where 1 = 1 ");
74         if (null != params) {
75             for (String key : params.keySet()) {
76                 hql.append(" and ");
77                 hql.append(key);
78                 hql.append(" = :");
79                 hql.append(key);
80             }
81         }
82         Query query = this.getSession().createQuery(hql.toString());
83         if (null != params) {
84             query.setProperties(params);
85         }
86         return query.list();
87     }
88 
89     @Override
90     public List<T> find(String hql, Map<String, Object> params) {
91         Query query = this.getSession().createQuery(hql.toString());
92         if (null != params) {
93             query.setProperties(params);
94         }
95         return query.list();
96     }
99 }

    8.hibernate.cfg.xml

     1 <?xml version="1.0" encoding="UTF-8"?>
 2 
 3 <!DOCTYPE hibernate-configuration PUBLIC
 4     "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
 5     "http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">
 6 
 7 <hibernate-configuration>
 8     <session-factory>
 9         <!-- 1.连接数据库 -->
10         <!-- 连接数据库名 -->
11         <property name="connection.url">jdbc:mysql://localhost:3306/hibernatedb</property>
12         
13         <!-- 连接数据库的用户名 -->
14         <property name="connection.username">root</property>
15         
16         <!-- 连接数据库的密码 -->
17         <property name="connection.password">root</property>
18         
19         <!-- 数据库驱动类 -->
20         <property name="connection.driver_class">com.mysql.jdbc.Driver</property>
21         
22         <!-- 2.数据库方言（不同的数据库） -->
23         <property name="dialect">org.hibernate.dialect.MySQL5Dialect</property>
24         
25         <!-- 3.其他属性 -->
26         <!-- 是否显示sql语句 -->
27         <property name="show_sql">true</property>
28         <!-- 是否显示格式化sql语句，如果要显示，★★★一定要先显示show_sql语句★★★ -->
29         <property name="format_sql">true</property>
30         
31         <!-- 4.数据库对应的实体类的映射文件路径 -->
32         <mapping resource="com/Elastic/HibernateDemo3/ivy/entity/Dept.hbm.xml"></mapping>
33     </session-factory>
34 </hibernate-configuration>

    9.HibernateUtil 类

     1 package com.Elastic.HibernateDemo3.ivy.util;
 2 
 3 import org.hibernate.Session;
 4 import org.hibernate.SessionFactory;
 5 import org.hibernate.cfg.Configuration;
 6 public final class HibernateUtil {
 7     private static Configuration cfg = null;
 8     private static SessionFactory sessionFactory = null;
 9     
10     //本地线程
11     public static ThreadLocal<Session> threadLocal = new ThreadLocal<Session>();
12     
13     static{
14         cfg = new Configuration().configure();
15         sessionFactory = cfg.buildSessionFactory();
16     }
17     
18     public static Session getSession(){
19         Session session = threadLocal.get();
20         if (null == session || !session.isOpen()) {
21             session = sessionFactory.openSession();
22             threadLocal.set(session);
23         }
24         return session;
25     }
26 }

    10.OpenSessionInViewFilter 类

     1 package com.Elastic.HibernateDemo3.ivy.filter;
 2 
 3 import java.io.IOException;
 4 
 5 import javax.servlet.Filter;
 6 import javax.servlet.FilterChain;
 7 import javax.servlet.FilterConfig;
 8 import javax.servlet.ServletException;
 9 import javax.servlet.ServletRequest;
10 import javax.servlet.ServletResponse;
11 
12 import org.hibernate.HibernateException;
13 import org.hibernate.Session;
14 import org.hibernate.Transaction;
15 
16 import com.Elastic.HibernateDemo3.ivy.util.HibernateUtil;
17 public class OpenSessionInViewFilter implements Filter{
18 
19     /* (non-Javadoc)
20      * @see javax.servlet.Filter#destroy()
21      */
22     @Override
23     public void destroy() {
24         // TODO Auto-generated method stub
25         
26     }
27 
28     /* (non-Javadoc)
29      * @see javax.servlet.Filter#doFilter(javax.servlet.ServletRequest, javax.servlet.ServletResponse, javax.servlet.FilterChain)
30      */
31     @Override
32     public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
33             throws IOException, ServletException {
34         
35         /*  事务以及session的关闭    */
36         
37         //获取session
38         Session session = HibernateUtil.getSession();
39         //开启事务
40         Transaction tx = session.beginTransaction();
41         
42         try {
43             chain.doFilter(request, response);
44             //提交事务
45             tx.commit();
46         } catch (HibernateException e) {
47             tx.rollback();
48             e.printStackTrace();
49         } finally {
50             //关闭session
51             session.close();
52         }
53         
54     }
55 
56     /* (non-Javadoc)
57      * @see javax.servlet.Filter#init(javax.servlet.FilterConfig)
58      */
59     @Override
60     public void init(FilterConfig arg0) throws ServletException {
61         // TODO Auto-generated method stub
62         
63     }
64 
65 }

    11.EncodingFilter 类

     1 package com.Elastic.HibernateDemo3.ivy.filter;
 2 
 3 import java.io.IOException;
 4 
 5 import javax.servlet.Filter;
 6 import javax.servlet.FilterChain;
 7 import javax.servlet.FilterConfig;
 8 import javax.servlet.ServletException;
 9 import javax.servlet.ServletRequest;
10 import javax.servlet.ServletResponse;
11 public class EncodingFilter implements Filter {
12 
13     /* (non-Javadoc)
14      * @see javax.servlet.Filter#destroy()
15      */
16     @Override
17     public void destroy() {
18         // TODO Auto-generated method stub
19 
20     }
21 
22     /* (non-Javadoc)
23      * @see javax.servlet.Filter#doFilter(javax.servlet.ServletRequest, javax.servlet.ServletResponse, javax.servlet.FilterChain)
24      */
25     @Override
26     public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
27             throws IOException, ServletException {
28         request.setCharacterEncoding("utf-8");
29         response.setCharacterEncoding("utf-8");
30         chain.doFilter(request, response);
31     }
32 
33     /* (non-Javadoc)
34      * @see javax.servlet.Filter#init(javax.servlet.FilterConfig)
35      */
36     @Override
37     public void init(FilterConfig arg0) throws ServletException {
38         // TODO Auto-generated method stub
39 
40     }
41 
42 }

    12.web.xml

     1 <?xml version="1.0" encoding="UTF-8"?>
 2 <web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" id="WebApp_ID" version="2.5">
 3   <display-name>HibernateDemo3_ivy</display-name>
 4   <welcome-file-list>
 5     <welcome-file>index.html</welcome-file>
 6     <welcome-file>index.htm</welcome-file>
 7     <welcome-file>index.jsp</welcome-file>
 8     <welcome-file>default.html</welcome-file>
 9     <welcome-file>default.htm</welcome-file>
10     <welcome-file>default.jsp</welcome-file>
11   </welcome-file-list>
12   
13   <!-- 编码格式放在最前面 -->
14   <filter>
15       <filter-name>encoding</filter-name>
16       <filter-class>com.Elastic.HibernateDemo3.ivy.filter.EncodingFilter</filter-class>
17   </filter>
18   <filter-mapping>
19       <filter-name>encoding</filter-name>
20       <url-pattern>/*</url-pattern>
21   </filter-mapping>
22   
23   <!-- 每个操作,事务都能正常操作 -->
24   <filter>
25       <filter-name>OpenSessionInView</filter-name>
26       <filter-class>com.Elastic.HibernateDemo3.ivy.filter.EncodingFilter</filter-class>
27   </filter>
28   <filter-mapping>
29       <filter-name>OpenSessionInView</filter-name>
30       <url-pattern>/*</url-pattern>
31   </filter-mapping>
32   
33   <servlet>
34     <description></description>
35     <display-name>DeptServlet</display-name>
36     <servlet-name>DeptServlet</servlet-name>
37     <servlet-class>com.Elastic.HibernateDemo3.ivy.controller.DeptServlet</servlet-class>
38   </servlet>
39   <servlet-mapping>
40     <servlet-name>DeptServlet</servlet-name>
41     <url-pattern>/DeptServlet</url-pattern>
42     <url-pattern>/dept/search</url-pattern>
43   </servlet-mapping>
44   
45 </web-app>

    13.DeptService 类

     1 package com.Elastic.HibernateDemo3.ivy.service;
 2 
 3 import java.util.List;
 4 import java.util.Map;
 5 
 6 import com.Elastic.HibernateDemo3.ivy.entity.Dept;
 7 
 8 public interface DeptService{
 9     List<Dept> searchALLDept();
10     
11     List<Dept> searchDeptsByName(String name);
12     
13     List<Dept> searchDeptByCondition(Map<String, Object> condition);
14 }

    14.DeptServiceImpl 类

     1 package com.Elastic.HibernateDemo3.ivy.service.impl;
 2 
 3 import java.util.HashMap;
 4 import java.util.List;
 5 import java.util.Map;
 6 
 7 import com.Elastic.HibernateDemo3.ivy.dao.DeptDao;
 8 import com.Elastic.HibernateDemo3.ivy.dao.impl.DeptDaoImpl;
 9 import com.Elastic.HibernateDemo3.ivy.entity.Dept;
10 import com.Elastic.HibernateDemo3.ivy.service.DeptService;
11 
12 public class DeptServiceImpl implements DeptService {
13 
14     private DeptDao deptDao = new DeptDaoImpl();
15 
16     /*
17      * (non-Javadoc)
18      * 
19      * @see com.Elastic.HibernateDemo3.ivy.service.DeptService#searchALLDept()
20      */
21     @Override
22     public List<Dept> searchALLDept() {
23         return deptDao.find(null);
24     }
25 
26     /*
27      * (non-Javadoc)
28      * 
29      * @see
30      * com.Elastic.HibernateDemo3.ivy.service.DeptService#searchDeptsByName(java
31      * .lang.String)
32      */
33     @Override
34     public List<Dept> searchDeptsByName(String name) {
35         Map<String, Object> params = new HashMap<String,Object>();
36         params.put("deptName", name);
37         
38         return deptDao.find(params);
39     }
40 
41     @Override
42     public List<Dept> searchDeptByCondition(Map<String, Object> condition) {
43         
44         return deptDao.find(condition);
45     }
46 
47 }

    15.DeptServlet 类

     1 package com.Elastic.HibernateDemo3.ivy.controller;
 2 
 3 import java.io.IOException;
 4 import java.util.HashMap;
 5 import java.util.List;
 6 import java.util.Map;
 7 
 8 import javax.servlet.ServletException;
 9 import javax.servlet.http.HttpServlet;
10 import javax.servlet.http.HttpServletRequest;
11 import javax.servlet.http.HttpServletResponse;
12 
13 import com.Elastic.HibernateDemo3.ivy.entity.Dept;
14 import com.Elastic.HibernateDemo3.ivy.service.DeptService;
15 import com.Elastic.HibernateDemo3.ivy.service.impl.DeptServiceImpl;
16 
17 
18 /**
19  * Servlet implementation class DeptServlet
20  */
21 public class DeptServlet extends HttpServlet {
22     private static final long serialVersionUID = 1L;
23        
24     /**
25      * @see HttpServlet#HttpServlet()
26      */
27     public DeptServlet() {
28         super();
29         // TODO Auto-generated constructor stub
30     }
31 
32     /**
33      * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
34      */
35     protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
36         String oper = request.getParameter("oper");
37         DeptService deptService = new DeptServiceImpl();
38         switch (oper) {
39         case "all":
40             List<Dept> depts = deptService.searchALLDept();
41             request.setAttribute("depts", depts);
42             
43             //转发
44             request.getRequestDispatcher("/dept.jsp").forward(request, response);
45             break;
46         case "byName":
47             request.setAttribute("depts", deptService.searchDeptsByName(request.getParameter("name")));
48             
49             //转发
50             request.getRequestDispatcher("/dept.jsp").forward(request, response);
51             break;
52         case "byCondition":
53             //获取页面提交的参数
54             String deptName = request.getParameter("deptName");
55             String location = request.getParameter("location");
56             String id = request.getParameter("deptId");
57             
58             //创建保存参数的map集合
59             Map<String, Object> condition = new HashMap<String, Object>();
60             if (null != deptName && deptName.trim().length() != 0) {
61                 //【属性名和页面参数一样要写对！！！】
62                 condition.put("deptName", deptName);
63             }
64             if (null != location && location.trim().length() != 0) {
65                 //【属性名和页面参数一样要写对！！！】
66                 condition.put("location", location);
67             }
68             if (null != id && id.trim().length() != 0) {
69                 //【属性名和页面参数一样要写对！！！】
70                 condition.put("deptId", Integer.parseInt(id));
71             }
72             
73             request.setAttribute("depts", deptService.searchDeptByCondition(condition));
74             
75             //转发
76             request.getRequestDispatcher("/dept.jsp").forward(request, response);
77             break;
78 
79         default:
80             break;
81         }
82     }
83 
84     /**
85      * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
86      */
87     protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
88         this.doGet(request, response);
89     }
90 
91 }
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  • 原文地址：https://www.cnblogs.com/ivy-xu/p/5592337.html
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