HibernateTemplate实现CRUD操作

时间:2021-11-11 08:34:45

---------------------siwuxie095

HibernateTemplate 实现 CRUD 操作

1、在 SSH 框架中使用 HibernateTemplate 模板类实现 CRUD 操作

2、HibernateTemplate 是 Spring 对 Hibernate 的封装

3、使用 HibernateTemplate 时,必须进行事务管理,否则将报错

建议:使用基于注解方式的声明式事务管理

4、测试

(1)编写一个实体类

User.java:

package com.siwuxie095.entity;

public class User {

private Integer uid;

private String username;

private String address;

public Integer getUid() {

return uid;

}

public void setUid(Integer uid) {

this.uid = uid;

}

public String getUsername() {

return username;

}

public void setUsername(String username) {

this.username = username;

}

public String getAddress() {

return address;

}

public void setAddress(String address) {

this.address = address;

}

@Override

public String toString() {

return "User [uid=" + uid + ", username=" + username +

", address=" + address + "]";

}

}

(2)编写一个 Action 类

UserAction.java:

package com.siwuxie095.action;

import com.opensymphony.xwork2.ActionSupport;

import com.siwuxie095.service.UserService;

public class UserAction extends ActionSupport {

private UserService userService;

public void setUserService(UserService userService) {

this.userService = userService;

}

@Override

public String execute() throws Exception {

//userService.add();

userService.find();

return "none";

}

}

(3)编写一个 Service 类

UserService.java:

package com.siwuxie095.service;

import org.springframework.transaction.annotation.Transactional;

import com.siwuxie095.dao.UserDao;

/**

* 在 Service 层进行声明式事务管理

* 即加上注解 @Transactional

*

* 使用 HibernateTemplate 实现 CRUD 操作,

* 一定要加上事务管理,否则将报错

*/

@Transactional

public class UserService {

private UserDao userDao;

public void setUserDao(UserDao userDao) {

this.userDao = userDao;

}

public void add() {

userDao.add();

}

public void find() {

userDao.find();

}

}

(4)编写一个 Dao 接口和其实现类:

UserDao.java:

package com.siwuxie095.dao;

public interface UserDao {

public void add();

public void find();

}

UserDaoImpl.java:

package com.siwuxie095.dao.impl;

import java.util.List;

import org.springframework.orm.hibernate5.HibernateTemplate;

import com.siwuxie095.dao.UserDao;

import com.siwuxie095.entity.User;

public class UserDaoImpl implements UserDao {

private HibernateTemplate hibernateTemplate;

public void setHibernateTemplate(HibernateTemplate hibernateTemplate) {

this.hibernateTemplate = hibernateTemplate;

}

@Override

public void add() {

User user=new User();

user.setUsername("小白");

user.setAddress("中国");

hibernateTemplate.save(user);

/*

* HibernateTemplate 还有 update()、delete() 方法,

* 都是直接传入对象即可

*/

}

@Override

public void find() {

// 根据 id 查询

User user=hibernateTemplate.get(User.class, 1);

System.out.println(user);

System.out.println("------------------");

// 查询所有

List<User> list=(List<User>) hibernateTemplate.find("from User");

for (User user1 : list) {

System.out.println(user1);

}

System.out.println("------------------");

// 根据条件查询

List<User> listx=(List<User>) hibernateTemplate.find("from User where username=?", "小黑");

for (User user2 : listx) {

System.out.println(user2);

}

/*

* HibernateTemplate 的 findByCriteria() 方法可以做到分页查询

*

* find() 方法则无法做到

*/

}

}

(5)在 Hibernate 映射配置文件中进行配置

User.hbm.xml:

<?xml version="1.0" encoding="UTF-8"?>

<!DOCTYPE hibernate-mapping PUBLIC

"-//Hibernate/Hibernate Mapping DTD 3.0//EN"

"http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">

<hibernate-mapping>

<class name="com.siwuxie095.entity.User" table="t_user">

<id name="uid" column="uid">

<generator class="native"></generator>

</id>

<property name="username" column="username"></property>

<property name="address" column="address"></property>

</class>

</hibernate-mapping>

(6)在 Hibernate 核心配置文件中进行配置

hibernate.cfg.xml:

<?xml version="1.0" encoding="UTF-8"?>

<!DOCTYPE hibernate-configuration PUBLIC

"-//Hibernate/Hibernate Configuration DTD 3.0//EN"

"http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">

<hibernate-configuration>

<session-factory>

<property name="hibernate.show_sql">true</property>

<property name="hibernate.format_sql">true</property>

<!-- 注意:只有配置 hibernate.hbm2ddl.auto 为 update,才能自动创建表 -->

<property name="hibernate.hbm2ddl.auto">update</property>

<property name="hibernate.dialect">org.hibernate.dialect.MySQLDialect</property>

<!--

原来的配置:

<property name="hibernate.current_session_context_class">thread</property>

在 SSH 框架整合中会报错,要么将这个配置删了,要么改成如下配置

参考链接:http://blog.****.net/maoyuanming0806/article/details/61417995

-->

<property name="hibernate.current_session_context_class">

org.springframework.orm.hibernate5.SpringSessionContext

</property>

<mapping resource="com/siwuxie095/entity/User.hbm.xml"/>

</session-factory>

</hibernate-configuration>

(7)在 Spring 核心配置文件中进行配置

applicationContext.xml:

<?xml version="1.0" encoding="UTF-8"?>

<beans xmlns="http://www.springframework.org/schema/beans"

xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

xmlns:aop="http://www.springframework.org/schema/aop"

xmlns:context="http://www.springframework.org/schema/context"

xmlns:tx="http://www.springframework.org/schema/tx"

xsi:schemaLocation="

http://www.springframework.org/schema/beans

http://www.springframework.org/schema/beans/spring-beans.xsd

http://www.springframework.org/schema/aop

http://www.springframework.org/schema/aop/spring-aop.xsd

http://www.springframework.org/schema/context

http://www.springframework.org/schema/context/spring-context.xsd

http://www.springframework.org/schema/tx

http://www.springframework.org/schema/tx/spring-tx.xsd">

<!-- (1) -->

<!-- 配置 C3P0 连接池 -->

<bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">

<property name="driverClass" value="com.mysql.jdbc.Driver"/>

<!--

jdbc:mysql:///test_db 是 jdbc:mysql://localhost:3306/test_db 的简写

-->

<property name="jdbcUrl" value="jdbc:mysql:///test_db"/>

<property name="user" value="root"/>

<property name="password" value="8888"/>

</bean>

<!-- SessionFactory 对象的创建交给 Spring 进行管理 -->

<bean id="sessionFactory"

class="org.springframework.orm.hibernate5.LocalSessionFactoryBean">

<!--

因为在 Hibernate 核心配置文件中,没有数据库配置,

而是在 Spring 的核心配置文件中进行配置,所以需要

注入 dataSource

LocalSessionFactoryBean 中有相关属性,所以可以

注入

-->

<property name="dataSource" ref="dataSource"></property>

<!-- 指定 Hibernate 核心配置文件的位置 -->

<property name="configLocations" value="classpath:hibernate.cfg.xml"></property>

</bean>

<!-- (2) -->

<!-- 配置 Action 对象 -->

<bean id="userAction" class="com.siwuxie095.action.UserAction" scope="prototype">

<property name="userService" ref="userService"></property>

</bean>

<!-- 配置 Service 对象 -->

<bean id="userService" class="com.siwuxie095.service.UserService">

<property name="userDao" ref="userDaoImpl"></property>

</bean>

<!-- 配置 Dao 实现类对象 -->

<bean id="userDaoImpl" class="com.siwuxie095.dao.impl.UserDaoImpl">

<property name="hibernateTemplate" ref="hibernateTemplate"></property>

</bean>

<!-- 配置 HibernateTemplate 对象 -->

<bean id="hibernateTemplate" class="org.springframework.orm.hibernate5.HibernateTemplate">

<!-- 注入 SessionFactory 对象 -->

<property name="sessionFactory" ref="sessionFactory"></property>

</bean>

<!-- (3) -->

<!-- 配置事务管理器 HibernateTransactionManager -->

<bean id="transactionManager"

class="org.springframework.orm.hibernate5.HibernateTransactionManager">

<!--注入 SessionFactory 对象 -->

<property name="sessionFactory" ref="sessionFactory"></property>

</bean>

<!-- 开启事务注解 -->

<tx:annotation-driven transaction-manager="transactionManager"/>

</beans>

(8)在 Struts2 核心配置文件中进行配置

struts.xml:

<?xml version="1.0" encoding="UTF-8" ?>

<!DOCTYPE struts PUBLIC

"-//Apache Software Foundation//DTD Struts Configuration 2.3//EN"

"http://struts.apache.org/dtds/struts-2.3.dtd">

<struts>

<package name="demo" extends="struts-default" namespace="/">

<!--

此时,class 属性对应 Spring 核心配置文件中 Bean 的 id

如果还写 Action 类的全限定名,Action 对象就会创建两次

-->

<action name="user" class="userAction"></action>

</package>

</struts>

(9)在部署描述文件中进行配置

web.xml:

<?xml version="1.0" encoding="UTF-8"?>

<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://xmlns.jcp.org/xml/ns/javaee" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd" version="3.1">

<welcome-file-list>

<welcome-file>index.jsp</welcome-file>

</welcome-file-list>

<filter>

<!-- 配置 Struts2 的核心过滤器 -->

<filter-name>struts2</filter-name>

<filter-class>org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter</filter-class>

</filter>

<filter-mapping>

<filter-name>struts2</filter-name>

<url-pattern>/*</url-pattern>

</filter-mapping>

<!-- 配置 Spring 的监听器 ContextLoaderListener -->

<listener>

<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>

</listener>

<!-- 配置 Spring 核心配置文件的位置(路径) -->

<context-param>

<param-name>contextConfigLocation</param-name>

<param-value>classpath:applicationContext.xml</param-value>

</context-param>

</web-app>

(10)访问路径

http://localhost:8080/工程名/user.action

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