• Spring和MyBatis配置补充(四)


    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);
            }
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  • 原文地址:https://www.cnblogs.com/newbest/p/9206085.html
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