学习依赖

导入依赖

<dependency>
    <groupId>junit</groupId>
    <artifactId>junit</artifactId>
    <version>4.13</version>
</dependency>
<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-webmvc</artifactId>
    <version>5.2.6.RELEASE</version>
</dependency>
<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-jdbc</artifactId>
    <version>5.2.6.RELEASE</version>
</dependency>
</dependencies>

byName:会自动在容器上下文中查找，和自己对象set方法后面值对应的 beanid
bytype:会自动在容器上下文中查找，和自己对象属性类型相同的bean

使用注解进行开发

开发之前需要引入头文件

<?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:context="http://www.springframework.org/schema/context"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
        https://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/context
        https://www.springframework.org/schema/context/spring-context.xsd">

    <context:annotation-config/>
    有些是文件创建就自动生成的

@Autowired() 是按照类型自动装配的

@Resource()

如有指定的name属性，先按该属性进行byName方式查找装配
其次在进行默认的byName方式进行装配
如果以上都不成功，则按byType的方式自动装配
都不成功就报异常

属性注入


@Component("user")
public class User {
    //相当于在配置文件中<property name="name" value="余浩"/>
    @Value("余浩")
    public String name;

如果提供了set方法，在set方法上添加@Valur("值")


@Component("user")
public class User {

    public String name;

    @Value("余浩")
    public void setName(String name) {
        this.name = name;
    }

衍生注解

@Controller：web层
@Service：service层
@Repository：dao层

它们功能都是一样的，写上这些注解，就是把这个类交给了Spring管理装配
xml和注解整合开发

xml管理bean
注解完成属性注入
context:annotation-config/

动态代理

核心：

InvocationHandler 和 Proxy

public class ProxyInvocationHandler implements InvocationHandler {
    private Rent rent;

    public void setRent(Rent rent) {
        this.rent = rent;
    }

    //生成代理类，获取要代理的抽象角色
    public Object getProxy() {
        return Proxy.newProxyInstance(this.getClass().getClassLoader(), rent.getClass().getInterfaces(), this);
    }

    @Override
    public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
        log(method.getName());
        Object result = method.invoke(rent, args);
        return result;
    }

    public void log(String methodName) {
        System.out.println("执行了" + methodName + "方法");
    }
}

动态代理的好处：

公共的业务由代理来完成，实现了业务的分工
公共业务发生拓展时变得更加集中和方便
一个动态代理类可以代理多个类，代理的是接口

AOP切面编程

导入约束

<?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"
        xsi:schemaLocation="http://www.springframework.org/schema/beans
        http://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/aop
        https://www.springframework.org/schema/aop/spring-aop.xsd">
</beans>

实现aop切入

    <!--注册bean-->
<bean id="userService"class="com.cqgs.service.UserServiceImpl"/>
<bean id="log"class="com.cqgs.log.Log"/>
<bean id="afterLog"class="com.cqgs.log.AfterLog"/>

<!--aop的配置-->
<aop:config>
<!--切入点 expression:表达式匹配要执行的方法-->
<aop:pointcut id="pointcut"expression="execution(* com.cqgs.service.UserServiceImpl.*(..))"/>
<!--执行环绕-->
<aop:advisor advice-ref="log"pointcut-ref="pointcut"/>
<aop:advisor advice-ref="afterLog"pointcut-ref="pointcut"/>
</aop:config>

自定义实现AOP

写入一个切入类

public class Diy {
    public void before() {
        System.out.println("方法执行前");
    }

    public void after() {
        System.out.println("方法执行后");
    }
}

配置
<!--注册bean-->
<bean id="userService"class="com.cqgs.service.UserServiceImpl"/>
<!--第二种自定义实现-->
<bean id="diy"class="com.cqgs.diy.Diy"/>
<aop:config>
<aop:aspect ref="diy">
<aop:pointcut id="diypointcut"expression="execution(* com.cqgs.service.UserServiceImpl.*(..))"/>
<aop:before pointcut-ref="diypointcut"method="before"/>
<aop:after pointcut-ref="diypointcut"method="after"/>
</aop:aspect>
</aop:config>

MyBatis整合

导入相关的jar包

junit


<dependency>
  <groupId>junit</groupId>
  <artifactId>junit</artifactId>
  <version>4.13</version>
</dependency>

MyBatis


<dependency>
    <groupId>org.mybatis</groupId>
    <artifactId>mybatis</artifactId>
    <version>3.5.7</version>
</dependency>

mysql-connector-java

<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
    <version>8.0.19</version>
</dependency>

spring相关

<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-webmvc</artifactId>
    <version>5.2.6.RELEASE</version>
</dependency>
<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-jdbc</artifactId>
    <version>5.2.6.RELEASE</version>
</dependency>

mybatis-spring整合包

<dependency>
    <groupId>org.mybatis</groupId>
    <artifactId>mybatis-spring</artifactId>
    <version>2.0.2</version>
</dependency>

`ClassPathXmlApplicationContextBeans.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:context="http://www.springframework.org/schema/context"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
        https://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/context
        https://www.springframework.org/schema/context/spring-context.xsd">
    <context:annotation-config/>

`mybatis-config.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>
    <properties resource="db.properties">
    </properties>
    <settings>
        <setting name="mapUnderscoreToCamelCase" value="true"/>
        <setting name="logImpl" value="STDOUT_LOGGING"/>
    </settings>

    <typeAliases>
        <package name="com.cqgs.pojo"/>
    </typeAliases>

    <environments default="development">
        <environment id="development">
            <transactionManager type="JDBC"/>
            <dataSource type="POOLED">
                <property name="driver" value="${driver}"/>
                <property name="url" value="${url}"/>
                <property name="username" value="${username}"/>
                <property name="password" value="${password}"/>
            </dataSource>
        </environment>
    </environments>
    <mappers>
        <mapper resource="com/cqgs/dao/BlogMapper.xml"/>

    </mappers>
</configuration>

`log4j.properties`

log4j.rootLogger=WARN, stdout
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%d %p [%c] - %m%n

`db.properties`

driver=com.mysql.cj.jdbc.Driver
url=jdbc:mysql://localhost:3306/cqgs?characterEncoding=utf8&allowPublicKeyRetrieval=true&serverTimezone=UTC
username=root
password=root123

`MyBatisUtils.java`

public class MyBatisUtils {
    private static SqlSessionFactory sqlSessionFactory;

    static {
        try {
            String resource = "mybatis-config.xml";
            InputStream inputStream = Resources.getResourceAsStream(resource);
            sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    public static SqlSession getSqlSession() {
        return sqlSessionFactory.openSession(true); //自动提交事务设置为true
    }
}

<?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="">

</mapper>

配置静态资源过滤问题

<build>
   <resources>
       <resource>
           <directory>src/main/java</directory>
           <includes>
               <include>**/*.properties</include>
               <include>**/*.xml</include>
           </includes>
           <filtering>true</filtering>
       </resource>
   </resources>
</build>

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


    <!--配置数据源-->
    <bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
        <property name="driverClassName" value="com.mysql.cj.jdbc.Driver"/>
        <property name="url"
                  value="jdbc:mysql://localhost:3306/cqgs?characterEncoding=utf8&amp;allowPublicKeyRetrieval=true&amp;serverTimezone=UTC"/>
        <property name="username" value="root"/>
        <property name="password" value="root123"/>
    </bean>
    <!--配置SqlSessionFactory-->
    <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
        <property name="dataSource" ref="dataSource"/>
        <!--关联mybatis-->
        <property name="configLocation" value="classpath:MyBatisConfig.xml"/>
        <property name="mapperLocations" value="classpath:com/cqgs/dao/*.xml"/>
    </bean>

    <!--使用 SqlSessionFactory 作为构造方法的参数来创建 SqlSessionTemplate 对象。-->
    <bean id="sqlSession" class="org.mybatis.spring.SqlSessionTemplate">
        <constructor-arg index="0" ref="sqlSessionFactory"/>
    </bean>
    <!--声明事务-->
    <bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
        <constructor-arg ref="dataSource" />
    </bean>
    <!--配置事务通知-->
    <tx:advice id="txAdvice" transaction-manager="transactionManager">
        <tx:attributes>
            <tx:method name="add" propagation="REQUIRED"/>
            <tx:method name="delet" propagation="REQUIRED"/>
            <tx:method name="update" propagation="REQUIRED"/>
            <tx:method name="serach" propagation="REQUIRED"/>
            <tx:method name="get" read-only="true"/>
            <tx:method name="*" propagation="REQUIRED"/>
        </tx:attributes>
    </tx:advice>

    <!--配置事务的切入点-->
    <aop:config>
        <aop:pointcut id="txPointCut" expression="execution(* com.cqgs.dao.*.*(..))"/>
        <aop:advisor advice-ref="txAdvice" pointcut-ref="txPointCut"/>
    </aop:config>

</beans>

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

    <import resource="spring-dao.xml"/>

    <!--注册bean实现-->
    <bean id="userMapper" class="com.cqgs.dao.UserMapperImpl">
        <property name="sqlSession" ref="sqlSession"/>
    </bean>

</beans>

最后的mybatisConfig.xml就只剩下

<?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>
    <!--    <settings>-->
    <!--        <setting name="mapUnderscoreToCamelCase" value="true"/>-->
    <!--        <setting name="logImpl" value="STDOUT_LOGGING"/>-->
    <!--    </settings>-->

    <typeAliases>
        <package name="com.cqgs.pojo"/>
    </typeAliases>

</configuration>

public class UserMapperImpl implements UserMapper {
    private SqlSessionTemplate sqlSession;

    public void setSqlSession(SqlSessionTemplate sqlSession) {
        this.sqlSession = sqlSession;
    }

    @Override
    public List<User> selectUser() {
        UserMapper mapper = sqlSession.getMapper(UserMapper.class);
        return mapper.selectUser();
    }
}

//第二种方式
public class UserServiceImpl2 extends SqlSessionDaoSupport implements UserMapper {
    @Override
    public List<User> selectUser() {
        return getSqlSession().getMapper(UserMapper.class).selectUser();
    }
}

为什么要配置事务：

如果不配置，就需要手动提交控制事务
设计到数据一致性问题，不容马虎！

spring-mybatis

posted @ 2021-11-10 09:13 这阵风是晚安阅读(32) 评论(0) 编辑收藏举报

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