ssm development focus, the purpose of each configuration file, maven sub-module project and configuration file

1. ssm development focus

1. What you want to use to directly echo data (annotation-driven, must be added, otherwise it will be troublesome to write back objects and collections
):

2. Form does not need name (you can write it), form item only needs name (input is summit or not name):

3.ajax return type:

6. Generally, the method of calling the service in the Controller, and the service is the method of calling dao.
7. Load the xxxMapper.xml file in sqlMapConfig.xml, UserMapper.xml writes the sql statement corresponding to the mapper layer (dao) interface. Mybatis just omits the impl of (mapper) dao, but the mapper interface still has to be written. Then spring can simplify the creation of polymorphic implementation classes, which are generally used in services. And Springmvc is responsible for the Controller layer, jsp requests to the Controller, then the Controller calls the Service layer, and the Service calls the mapper layer.

8. Generally, spring-mvc is only responsible for the controller package, while applicationContext.xml is responsible for business packages such as dao, service, etc. It is divided into several xmls to separate business and logic control.

9. Inject service into the Controller class (not to write ServiceImpl). Inject the mapper interface in the ServiceImpl class. The mapper interface is combined with xxxMapper.xml, it does not need to inject the implementation class of its mapper ( applicationContext.xml will scan the mapper layer to automatically create its implementation class ), because the mapper layer does not have impl, xxxMapper.Xml will be in sqlMapConfig.xml Loading the loaded is equivalent to impl. (The interface must be the same as the package name of the xml where the interface is placed before it can be scanned, otherwise an error will be reported, which has troubled me for several days)

10. To build a package in resources, you must use/separate, and to build a package in java, you can use a dot to separate

Second, the purpose of each configuration file

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:tx="http://www.springframework.org/schema/tx"
       xmlns:context="http://www.springframework.org/schema/context"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/tx
http://www.springframework.org/schema/tx/spring-tx.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">

    <!--组件扫描 扫描service和mapper-->
    <context:component-scan base-package="com.itheima">
        <!--排除controller的扫描-->
        <context:exclude-filter type="annotation" expression="org.springframework.stereotype.Controller"></context:exclude-filter>
    </context:component-scan>

    <!--加载propeties文件-->
    <context:property-placeholder location="classpath:jdbc.properties"></context:property-placeholder>

    <!--配置数据源信息-->
    <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
        <property name="driverClass" value="${jdbc.driver}"></property>
        <property name="jdbcUrl" value="${jdbc.url}"></property>
        <property name="user" value="${jdbc.username}"></property>
        <property name="password" value="${jdbc.password}"></property>
    </bean>

    <!--配置sessionFactory-->
    <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
        <property name="dataSource" ref="dataSource"></property>
        <!--加载mybatis核心文件-->
        <property name="configLocation" value="classpath:sqlMapConfig.xml"></property>
    </bean>

    <!--扫描mapper.xml（也要和接口的包名一致才行,也可以说是扫接口）所在的包 为mapper创建实现类-->
    <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
        <!--<mapper resource="com/itheima/mapper/AccountMapper.xml"></mapper>-->
        <!--这是扫对应mapper.xml（也要和接口的包名一致才行,也可以说是扫接口）那个包-->
        <property name="basePackage" value="com.itheima.mapper"></property>
    </bean>


    <!--声明式事务控制-->
    <!--平台事务管理器-->
    <bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
        <property name="dataSource" ref="dataSource"></property>
    </bean>

    <!--配置事务增强-->
    <tx:advice id="txAdvice">
        <tx:attributes>
            <tx:method name="*"/>
        </tx:attributes>
    </tx:advice>

    <!--事务的aop织入-->
    <aop:config>
        <aop:advisor advice-ref="txAdvice" pointcut="execution(* com.itheima.service.impl.*.*(..))"></aop:advisor>
    </aop:config>

</beans>

spring-mvc.xml:

<?xml version="1.0" encoding="UTF-8" ?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:mvc="http://www.springframework.org/schema/mvc"
       xmlns:context="http://www.springframework.org/schema/context"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/mvc
http://www.springframework.org/schema/mvc/spring-mvc.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context.xsd">

    <!--组件扫描  主要扫描controller-->
    <context:component-scan base-package="com.itheima.controller"></context:component-scan>
    <!--配置mvc注解驱动-->
    <mvc:annotation-driven></mvc:annotation-driven>
    <!--内部资源视图解析器-->
    <bean id="resourceViewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="prefix" value="/WEB-INF/pages/"></property>
        <property name="suffix" value=".jsp"></property>
    </bean>
    <!--开发静态资源访问权限-->
    <mvc:default-servlet-handler></mvc:default-servlet-handler>


</beans>

sqlMapConfig.xml:

<?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>

    <!--定义别名-->
    <typeAliases>
        <!--<typeAlias type="com.itheima.domain.Account" alias="account"></typeAlias>-->
        <package name="com.itheima.domain"></package>
    </typeAliases>

</configuration>

com/itheima/mapper/AccountMapper.xml:

<?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="com.itheima.mapper.AccountMapper">
    <insert id="save" parameterType="account">
        insert into account values(#{id},#{name},#{money})
    </insert>
    <select id="findAll" resultType="account">
        select * from account
    </select>
</mapper>

Three, maven sub-module project and configuration files

The previous configuration file is like this:
now we generally subdivide it into this way:
subdivide applicationContext.xml into applicationContext-dao/service.xml.
The core configuration file (springConfig.xml) of mybatis is no longer needed, it has been placed in applicationContext-dao

applicationContext-dao.xml：

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:context="http://www.springframework.org/schema/context"
       xmlns:p="http://www.springframework.org/schema/p"
       xmlns:aop="http://www.springframework.org/schema/aop"
       xmlns:tx="http://www.springframework.org/schema/tx"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       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.xsd
						   http://www.springframework.org/schema/aop
						   http://www.springframework.org/schema/aop/spring-aop.xsd
						   http://www.springframework.org/schema/tx
						   http://www.springframework.org/schema/tx/spring-tx.xsd">

    <!--配置数据源信息，使用druid连接池-->
    <bean id="dataSource" class="com.alibaba.druid.pool.DruidDataSource">
        <property name="driverClassName" value="com.mysql.jdbc.Driver"/>
        <property name="url" value="jdbc:mysql://localhost:3306/ssmtest"/>
        <property name="username" value="root"/>
        <property name="password" value="root"/>
    </bean>
    <!--配置spring整合mybatis框架的SQLSessionFactoryBean-->
    <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
        <property name="dataSource" ref="dataSource"/>
        <!--扫描pojo包，为实体类创建别名-->
        <property name="typeAliasesPackage" value="com.itheima.ssm.pojo"/>
    </bean>

    <!--mapper扫描器，用于产生代理对象-->
    <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
        <property name="basePackage" value="com.itheima.ssm.dao"/>
    </bean>
</beans>

applicationContext-service.xml:

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:context="http://www.springframework.org/schema/context"
       xmlns:p="http://www.springframework.org/schema/p"
       xmlns:aop="http://www.springframework.org/schema/aop"
       xmlns:tx="http://www.springframework.org/schema/tx"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       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.xsd
						   http://www.springframework.org/schema/aop
						   http://www.springframework.org/schema/aop/spring-aop.xsd
						   http://www.springframework.org/schema/tx
						   http://www.springframework.org/schema/tx/spring-tx.xsd">

    <!--配置扫描器，扫描Service-->
    <context:component-scan base-package="com.itheima.ssm.service"/>

    <!--事务管理器-->
    <bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
        <property name="dataSource" ref="dataSource"/>
    </bean>

    <!--事物注解驱动-->
    <tx:annotation-driven transaction-manager="transactionManager"/>
</beans>

springmvc.xml:

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:context="http://www.springframework.org/schema/context"
       xmlns:p="http://www.springframework.org/schema/p"
       xmlns:aop="http://www.springframework.org/schema/aop"
       xmlns:tx="http://www.springframework.org/schema/tx"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       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.xsd
						   http://www.springframework.org/schema/aop
						   http://www.springframework.org/schema/aop/spring-aop.xsd
						   http://www.springframework.org/schema/tx
						   http://www.springframework.org/schema/tx/spring-tx.xsd">

    <!--配置扫描器，扫描Controller-->
    <context:component-scan base-package="com.itheima.ssm.controller"/>

    <!--视图解析器-->
    <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="prefix" value="/WEB-INF/jsp"/>
        <property name="suffix" value=".jsp"/>
    </bean>
</beans>

com/itheima/dao/ItemMapper.xml:

<?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="com.itheima.ssm.dao.ItemMapper">
    <select id="findById" parameterType="int" resultType="Item">
        select * from item where id = #{id}
    </select>
</mapper>