Spring整合mybatis完整示例

桃扇骨 2022-05-19 02:07 215阅读 0赞

# Spring整合mybatis完整示例 #

### 实现功能：根据id查找用户信息。 ###

### 1、首先创建一个与表中数据相对应的实体类，User.java ###

package bean;
    
    public class User {
        int id;
        String name;
        int age;
        String sex;
        String school;
    
        public int getId() {
            return id;
        }
    
        public void setId(int id) {
            this.id = id;
        }
    
        public String getName() {
            return name;
        }
    
        public void setName(String name) {
            this.name = name;
        }
    
        public int getAge() {
            return age;
        }
    
        public void setAge(int age) {
            this.age = age;
        }
    
        public String getSex() {
            return sex;
        }
    
        public void setSex(String sex) {
            this.sex = sex;
        }
    
        public String getSchool() {
            return school;
        }
    
        public void setSchool(String school) {
            this.school = school;
        }
    
        @Override
        public String toString() {
            return ("姓名："+name+"\n年龄："+age+"\n性别"+sex+"\n学校"+school);
        }
    }

## ##

### 2、写出这个类的映射接口，里面有我们要实现的查询的抽象方法。 ###

package dao;
    
    import bean.User;
    
    public interface IUser {
        User getUserByID (int id);
    }

### 3、写出这个类的映射Mapper文件，里面有select语句。 ###

<?xml version="1.0" encoding="UTF-8"?>
    <!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
            "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
    <mapper namespace="dao.IUser">
    
        <select id="getUserByID" resultType="User" parameterType="int">
            SELECT * from user where id = #{id}
        </select>
    
    
    </mapper>

### 4、以上都准备好之后，后面就是与没用spring不同的地方。 ###

*  准备mysql.properteis的参数配置文件，里面写上数据库连接要用到的参数。
 *      jdbc.driver=com.mysql.jdbc.Driver
        jdbc.url=jdbc:mysql://localhost/test?useUnicode=true&characterEncoding=UTF-8
        jdbc.uid=root
        jdbc.password=123456
    
      
     
 *  mybatis文件与之前不同，之前实在**mybatis-config.xml**中配置数据库连接的，现在要把这些放在spring的配置文件中，所以mybatis配置文件中只写类的别名和引用的Mapper
 *      <?xml version="1.0" encoding="UTF-8"?>
        <!DOCTYPE configuration PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
                "http://mybatis.org/dtd/mybatis-3-config.dtd">
        
        
        
        
        <configuration>
            <typeAliases>
                <typeAlias alias="User" type="bean.User"/>
            </typeAliases>
        
            
                
                    
                    
                        
                        
                        
                        
                    
                
            
        
        
            <mappers>
                
                <mapper resource="xml/User.xml"/>
            </mappers>
        
        
        
        </configuration>
    
     
 *  在**spring-config.xml中，**我们要配置数据库连接池，和sqlSessionFactory对象，以及UserMapper对象。
    
     *  sqlSessionFactory中引用mybatis-config.xml文件
     *  userMapper中标明要实现的接口

<?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:p="http://www.springframework.org/schema/p"
            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/context
           http://www.springframework.org/schema/context/spring-context-4.2.xsd
            http://www.springframework.org/schema/aop
            http://www.springframework.org/schema/aop/spring-aop-4.3.xsd
            http://www.springframework.org/schema/tx
            http://www.springframework.org/schema/tx/spring-tx-4.3.xsd">
    
    
    
    
    <bean id="propertyConfigurer" class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
        <property name="locations">
            <list>
                <value>
                    mysql-local.properties
                </value>
            </list>
        </property>
    </bean>
    
    
        
        <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
            <property name="driverClass" value="${jdbc.driver}"/>
            <property name="jdbcUrl" value="${jdbc.url}"/>
            <property name="user" value="${jdbc.uid}"/>
            <property name="password" value="${jdbc.password}"/>
            
            <property name="initialPoolSize" value="10"/>
            
            <property name="minPoolSize" value="5"/>
            <property name="maxPoolSize" value="20"/>
         </bean>
    
    
        
        <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
            
            <property name="dataSource" ref="dataSource"/>
            <property name="configLocation" value="mybatis-spring-config.xml"/>
    
        </bean>
    
        
            
        
    
        
        <bean id="userMapper" class="org.mybatis.spring.mapper.MapperFactoryBean">
            <property name="mapperInterface" value="dao.IUser"/>
            <property name="sqlSessionFactory" ref="sqlSessionFactory"/>
        </bean>
    
    </beans>

## ##

### 5、以上3个xml文件都配置完成之后，我们调用这个查询方法就只需要短短几行代码。 ###

package bean;
    
    import dao.IUser;
    import org.apache.ibatis.session.SqlSession;
    import org.springframework.context.ApplicationContext;
    import org.springframework.context.support.ClassPathXmlApplicationContext;
    
    public class DemoTest {
        public static void main(String[] args) {
            ApplicationContext context = new ClassPathXmlApplicationContext("spring-config.xml");
            IUser userMapper = (IUser)context.getBean("userMapper");
            User user = userMapper.getUserByID(2);
            System.out.println(user);
    
        }
    
    }

### 6、运行结果 ###

![70][]

[70]: /images/20220519/f907aa9e76564a3f81850607e4a017b5.png