SpringMVC(3) SSM框架整合

2022-09-19

SpringMVC

2.1 一些准备：

数据库环境

创建一个存放书籍数据的数据库表

CREATE DATABASE `ssmbuild`;

USE `ssmbuild`;

DROP TABLE IF EXISTS `books`;

CREATE TABLE `books` (
`bookID` INT(10) NOT NULL AUTO_INCREMENT COMMENT '书id',
`bookName` VARCHAR(100) NOT NULL COMMENT '书名',
`bookCounts` INT(11) NOT NULL COMMENT '数量',
`detail` VARCHAR(200) NOT NULL COMMENT '描述',
KEY `bookID` (`bookID`)
) ENGINE=INNODB DEFAULT CHARSET=utf8

INSERT  INTO `books`(`bookID`,`bookName`,`bookCounts`,`detail`)VALUES
(1,'Java',1,'从入门到放弃'),
(2,'MySQL',10,'从删库到跑路'),
(3,'Linux',5,'从进门到进牢');

基本环境搭建

1、新建一Maven项目！ssmbuild ， 添加web的支持

2、导入相关的pom依赖！

3、Maven资源过滤设置

4、避免中文注释捣乱在pom.xml中的properties标签下加上：

<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>

5、建立基本结构和配置框架！

pojo
dao
service
controller

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>
  
</configuration>

applicationContext.xml（Spring核心配置文件）

2.2 Mybatis层编写

1、数据库配置文件 database.properties

jdbc.driver=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/ssmbuild?useSSL=true&useUnicode=true&characterEncoding=utf8
jdbc.username=root
jdbc.password=123456

2、IDEA关联数据库

3、编写MyBatis的核心配置文件

<?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>
       <package name="com.kuang.pojo"/>
   </typeAliases>
   <mappers>
       <mapper resource="com/kuang/dao/BookMapper.xml"/>
   </mappers>

</configuration>

<配置数据源可以交给spring去做>

4、编写数据库对应的实体类 com.bo.pojo.Books

public class Books {
    private int bookID;
    private String bookName;
    private int bookCounts;
    private String detail;
构造，get、set，tostring

5、编写Dao层的 Mapper接口！

public interface BookMapper {
    int addBook(Books book);

    //根据id删除一个Book
    int deleteBookById(int id);

    //更新Book
    int updateBook(Books books);

    //根据id查询,返回一个Book
    Books queryBookById(int id);

    //查询全部Book,返回list集合
    List<Books> queryAllBook();
}

6、编写接口对应的 Mapper.xml 文件。需要导入MyBatis的包:

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
        PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">

然后mapper下面写sql就行：

 <!--增加一个Book-->
   <insert id="addBook" parameterType="Books">
      insert into ssmbuild.books(bookName,bookCounts,detail)
      values (#{bookName}, #{bookCounts}, #{detail})
   </insert>

   <!--根据id删除一个Book-->
   <delete id="deleteBookById" parameterType="int">
      delete from ssmbuild.books where bookID=#{bookID}
   </delete>

   <!--更新Book-->
   <update id="updateBook" parameterType="Books">
      update ssmbuild.books
      set bookName = #{bookName},bookCounts = #{bookCounts},detail = #{detail}
      where bookID = #{bookID}
   </update>

   <!--根据id查询,返回一个Book-->
   <select id="queryBookById" resultType="Books">
      select * from ssmbuild.books
      where bookID = #{bookID}
   </select>

   <!--查询全部Book-->
   <select id="queryAllBook" resultType="Books">
      SELECT * from ssmbuild.books
   </select>

</mapper>

7、编写Service层的接口和实现类

//BookService:底下需要去实现,调用dao层
public interface BookService {
   //增加一个Book
   int addBook(Books book);
   //根据id删除一个Book
   int deleteBookById(int id);
   //更新Book
   int updateBook(Books books);
   //根据id查询,返回一个Book
   Books queryBookById(int id);
   //查询全部Book,返回list集合
   List<Books> queryAllBook();
}

实现类：

public class BookServiceImpl implements BookService {
    //调用dao层的操作，把dao层组合进来设置一个set，方便Spring管理
    private BookMapper bookMapper;

    public void setBookMapper(BookMapper bookMapper) {
        this.bookMapper = bookMapper;
    }
    @Override
    public int addBook(Books book) {
        return this.bookMapper.addBook(book);
    }

    @Override
    public int deleteBookById(int id) {
        return this.bookMapper.deleteBookById(id);
    }

    @Override
    public int updateBook(Books books) {
        return this.bookMapper.updateBook(books);
    }

    @Override
    public Books queryBookById(int id) {
        return this.bookMapper.queryBookById(id);
    }

    @Override
    public List<Books> queryAllBook() {
        return this.bookMapper.queryAllBook();
    }
}

2.3 Spring层

1、配置Spring整合MyBatis，我们这里数据源使用c3p0连接池；

2、我们去编写Spring整合Mybatis的相关的配置文件；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"
       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/context
       https://www.springframework.org/schema/context/spring-context.xsd">

    <!-- 配置整合mybatis -->
    <!-- 1.关联数据库文件 -->
    <context:property-placeholder location="classpath:database.properties"/>

    <!-- 2.数据库连接池 -->
    <!--数据库连接池
        dbcp 半自动化操作 不能自动连接
        c3p0 自动化操作（自动的加载配置文件 并且设置到对象里面）
    -->
    <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
        <!-- 配置连接池属性 -->
        <property name="driverClass" value="${jdbc.driver}"/>
        <property name="jdbcUrl" value="${jdbc.url}"/>
        <property name="user" value="${jdbc.username}"/>
        <property name="password" value="${jdbc.password}"/>

        <!-- c3p0连接池的私有属性 -->
        <property name="maxPoolSize" value="30"/>
        <property name="minPoolSize" value="10"/>
        <!-- 关闭连接后不自动commit -->
        <property name="autoCommitOnClose" value="false"/>
        <!-- 获取连接超时时间 -->
        <property name="checkoutTimeout" value="10000"/>
        <!-- 当获取连接失败重试次数 -->
        <property name="acquireRetryAttempts" value="2"/>
    </bean>

    <!-- 3.配置SqlSessionFactory对象 -->
    <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
        <!-- 注入数据库连接池 -->
        <property name="dataSource" ref="dataSource"/>
        <!-- 配置MyBaties全局配置文件:mybatis-config.xml -->
        <property name="configLocation" value="classpath:mybatis-config.xml"/>
    </bean>

    <!-- 4.配置扫描Dao接口包，动态实现Dao接口注入到spring容器中 -->
    <!--解释 ：https://www.cnblogs.com/jpfss/p/7799806.html-->
    <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
        <!-- 注入sqlSessionFactory -->
        <property name="sqlSessionFactoryBeanName" value="sqlSessionFactory"/>
        <!-- 给出需要扫描Dao接口包 -->
        <property name="basePackage" value="com.bo.dao"/>
    </bean>

</beans>

3、Spring整合service层

<?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
       http://www.springframework.org/schema/beans/spring-beans.xsd
       http://www.springframework.org/schema/context
       https://www.springframework.org/schema/context/spring-context.xsd">
    <import resource="classpath:spring-dao.xml"/>

    <!--扫描service包-->
    <context:component-scan base-package="com.bo.service"/>
    <!--将所有业务类注入到spring容器-->
    <bean id="BookServiceImpl" class="com.bo.service.BookServiceImpl">
        <property name="bookMapper" ref="bookMapper"/>
    </bean>
    <!-- 配置事务管理器 -->
    <bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
        <!-- 注入数据库连接池 -->
        <property name="dataSource" ref="dataSource" />
    </bean>

</beans>

疑问：

<bean id="BookServiceImpl" class="com.bo.service.BookServiceImpl">
        <property name="bookMapper" ref="bookMapper"/>
    </bean>

这里的bookMapper是哪里来的？，前面好像并没有配置文件注入了bookMapper，那么ref从何而来。

看这句代码，显然，bookmapper来源只能是spring-dao.xml，根据映射关系，bookMapper这个接口与bookMapper的配置文件是绑定的，我们之前是吧xml文件注册到了spring中

现在我们是这样搞的：

 <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
        <!-- 注入sqlSessionFactory -->
        <property name="sqlSessionFactoryBeanName" value="sqlSessionFactory"/>
        <!-- 给出需要扫描Dao接口包 -->
        <property name="basePackage" value="com.bo.dao"/>
    </bean>

扫瞄的包可以被spring识别，因此就行了