Spring和MyBatis配置补充

Posted 2020-11-19 刚刚睡醒

一、配置properties属性文件读取数据源信息

　1、db.properties的配置属性文件　

driver=com.mysql.jdbc.Driver
url=jdbc:mysql://localhost:3306/test?characterEncoding=utf-8
name=root
pass=0000

　2、spring核心配置文件的编写

<!-- 使用属性文件配置数据源 -->
　　<bean id="propertyPlaceholderConfigurer" class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
        <property name="location" value="classpath:db.properties"/>
    </bean>
    <bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource">
        <property name="driverClassName" value="${driver}"></property>
        <property name="url" value="${url}"></property>
        <property name="username" value="${name}"></property>
        <property name="password" value="${pass}"></property>
    </bean>
    
    <bean id="sqlSessionFactoryBean" class="org.mybatis.spring.SqlSessionFactoryBean">
        <property name="dataSource" ref="dataSource"/>
        <property name="configLocation" value="classpath:configuration.xml"/>
        <property name="mapperLocations">
            <list>
                <value>com/entity/*.xml</value>
            </list>
        </property>
    </bean>
    
    <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
        <property name="basePackage" value="com.mapper"/>
    </bean>
    
    <bean id="userService" class="com.service.UserService">
        <property name="userMapper" ref="userMapper"/>
    </bean>

　

二、通过JNDI读取数据源信息的配置

　　1、在META-INF目录下配置context.xml文件

<?xml version="1.0" encoding="UTF-8"?>
<Context>
           <Resource name="jdbc/news" auth="Container" type="javax.sql.DataSource"
          maxActive="100" maxIdle="30" maxWait="10000" 
          username="root"
           password="0000" 
           driverClassName="com.mysql.jdbc.Driver"
          url="jdbc:mysql://127.0.0.1:3306/test?characterEncoding=utf-8" />
</Context>

　　2、spring核心配置文件的编写

　　

<!-- 通过JNDI配置DataSource -->
    <bean id="dataSource" class="org.springframework.jndi.JndiObjectFactoryBean">
        <!--通过jndiName指定引用的JNDI数据源名称 -->
        <property name="jndiName">
            <value>java:comp/env/abc</value>
        </property>
    </bean>
    
    
    <bean id="sqlSessionFactoryBean" class="org.mybatis.spring.SqlSessionFactoryBean">
        <property name="dataSource" ref="dataSource"/>
        <property name="configLocation" value="classpath:configuration.xml"/>
        <property name="mapperLocations">
            <list>
                <value>com/entity/*.xml</value>
            </list>
        </property>
    </bean>
    
    <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
        <property name="basePackage" value="com.mapper"/>
    </bean>
    
    <bean id="userService" class="com.service.UserService">
        <property name="userMapper" ref="userMapper"/>
    </bean>

 

三、bean的单例和原型的两种设置

<!-- 可以在bean的配置中设置 -->
    <bean id="user" class="com.entity.User" scope="singleton"></bean>
    <bean id="user" class="com.entity.User" scope="prototype"></bean>

//注解的方式设置bean的作用域
@Component
//@Scope("singleton")
@Scope("prototype")
public class User {
    private Integer uid;
    private String uname;
}

<!-- 使用注解spring的配置文件中需设置自动扫描 -->
    <context:component-scan base-package="com.entity"/>

 

四、spring中多种方式的自动装配

　　1、在类中使用注解进行装配

@Service
public class UserService {
    @Autowired //or @Resource
    private UserMapper userMapper;
    
    public void setUserMapper(UserMapper userMapper) {
        this.userMapper = userMapper;
    }

    public List<User> findAll(){
        return userMapper.findAll();
    }
}

　　2、在配置文件中设置autowire属性进行注入　

<!-- 在配置文件中设置autowire属性进行注入 -->
    <bean id="userService" class="com.service.UserService" autowire="byName">
        <!-- <property name="userMapper" ref="userMapper"/> -->
    </bean>

　　      也可以设置全局的装配方式，但要注意bean的作用域，需要进行spring核心文件的拆分

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

    default-autowire="byName"
    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-3.1.xsd
    http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.1.xsd
    http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.1.xsd
    http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.1.xsd">
    
    ......省略
    
    <!-- 在配置文件中设置autowire属性进行注入 -->
    <bean id="userService" class="com.service.UserService">
        <!-- <property name="userMapper" ref="userMapper"/> -->
    </bean> 
</beans>

　　

五、spring核心文件的拆分

<!-- spring文件拆分后可以用import标签导入 -->
<import resource="classpath:applicationContext.xml"/>

 

六、一键生成的工具使用　　

SqlSessionFactoryBuilder builder=new SqlSessionFactoryBuilder();
        SqlSessionFactory f=builder.build(Test.class.getClassLoader().getResourceAsStream("configuration.xml"));
        SqlSession s=f.openSession();
        StudentMapper m=s.getMapper(StudentMapper.class);
        
        //m.insert();//如果实体中的属性值为null，则会把null插入到表中
        //m.insertSelective();//如果实体中的属性值为null，则不会把null插入到表中，而是走数据库的null值，效率高
        
        //m.deleteByPrimaryKey(id);//普通删除
        
        //m.updateByPrimaryKey(record);//如果实体中的属性值是null，则会把表中该列设置成null值
        //m.updateByPrimaryKeySelective(record);//如果实体中的属性值是null，则不会动表中该列，效率高
        
        //m.selectByPrimaryKey(id);//普通的查询
        StudentExample e=new StudentExample();
        Criteria c=e.createCriteria();
        c.andAgeGreaterThanOrEqualTo(20);
        c.andNameLike("%李%3%");
        List<Student> list=m.selectByExample(e);
        for (Student student : list) {
            System.out.println(student);
        }