day62 JavaWeb框架阶段—— Mybatis的注解开发&SSM框架整合（原始方式整合&Spring整合MyBatis& MyBatis的注解实现复杂映射开发）

今日内容

• Mybatis的注解开发
• SSM框架整合

今日源码：
链接：https://pan.baidu.com/s/1MNV1nB4F6s5KuF3MnqLVmw
提取码：g0er

Mybatis的注解开发

1.1 MyBatis的常用注解

这几年来注解开发越来越流行，Mybatis也可以使用注解开发方式，这样我们就可以减少编写Mapper

映射文件了。我们先围绕一些基本的CRUD来学习，再学习复杂映射多表操作。

@Insert：实现新增

@Update：实现更新

@Delete：实现删除

@Select：实现查询

@Result：实现结果集封装

@Results：可以与@Result 一起使用，封装多个结果集

@One：实现一对一结果集封装

@Many：实现一对多结果集封装

1.2 MyBatis的增删改查

我们完成简单的user表的增删改查的操作

private UserMapper userMapper;

@Before
public void before() throws IOException {
    InputStream resourceAsStream = Resources.getResourceAsStream("SqlMapConfig.xml");
    SqlSessionFactory sqlSessionFactory = new 
                 SqlSessionFactoryBuilder().build(resourceAsStream);
    SqlSession sqlSession = sqlSessionFactory.openSession(true);
    userMapper = sqlSession.getMapper(UserMapper.class);
}

@Test
public void testAdd() {
    User user = new User();
    user.setUsername("测试数据");
    user.setPassword("123");
    user.setBirthday(new Date());
    userMapper.add(user);
}
@Test
public void testUpdate() throws IOException {
    User user = new User();
    user.setId(16);
    user.setUsername("测试数据修改");
    user.setPassword("abc");
    user.setBirthday(new Date());
    userMapper.update(user);
}

@Test
public void testDelete() throws IOException {
    userMapper.delete(16);
}
@Test
public void testFindById() throws IOException {
    User user = userMapper.findById(1);
    System.out.println(user);
}
@Test
public void testFindAll() throws IOException {
    List<User> all = userMapper.findAll();
    for(User user : all){
        System.out.println(user);
    }
}

修改MyBatis的核心配置文件，我们使用了注解替代的映射文件，所以我们只需要加载使用了注解的Mapper接口即可

<mappers>
    <!--扫描使用注解的类-->
    <mapper class="cn.wbslz.mapper.UserMapper"></mapper>
</mappers>

或者指定扫描包含映射关系的接口所在的包也可以

<mappers>
    <!--扫描使用注解的类所在的包-->
    <package name="cn.wbslz.mapper"></package>
</mappers>

1.3 MyBatis的注解实现复杂映射开发

实现复杂关系映射之前我们可以在映射文件中通过配置来实现，使用注解开发后，我们可以使用@Results注解，@Result注解，@One注解，@Many注解组合完成复杂关系的配置

1.4 一对一查询

1.4.1 一对一查询的模型

用户表和订单表的关系为，一个用户有多个订单，一个订单只从属于一个用户

一对一查询的需求：查询一个订单，与此同时查询出该订单所属的用户

1.4.2 一对一查询的语句

对应的sql语句：

select * from orders;

select * from user where id=查询出订单的uid;

查询的结果如下：

1.4.3 创建Order和User实体

public class Order {

    private int id;
    private Date ordertime;
    private double total;

    //代表当前订单从属于哪一个客户
    private User user;
}

public class User {
    
    private int id;
    private String username;
    private String password;
    private Date birthday;

}

1.4.4 创建OrderMapper接口

public interface OrderMapper {
    List<Order> findAll();
}

1.4.5 使用注解配置Mapper

public interface OrderMapper {
    /**
     * 一对一查询
     * 两张表分开查
     * @return
     */
    @Select("select * from orders")
    @Results({
            @Result(column = "id",property = "id"),
            @Result(column = "ordertime",property = "ordertime"),
            @Result(column = "total",property = "total"),
            @Result(
                    property = "user", //要封装的属性名称
                    column = "uid", //根据那个字段去查询user表的数据
                    javaType = User.class, //要封装的实体类型
                    //select属性 代表查询那个接口的方法获得数据
                    one = @One(select = "cn.wbslz.mapper.UserMapper.findById")
            )
    })
    public List<Order> findAll();
}

public interface UserMapper {

    @Select("select * from user where id=#{id}")
    User findById(int id);
    
}

1.4.6 测试结果

 	@Test
    public void testfindAll(){
        List<Order> all = mapper.findAll();
        for (Order order:all){
            System.out.println(order);
        }
    }

1.5 一对多查询

1.5.1 一对多查询的模型

用户表和订单表的关系为，一个用户有多个订单，一个订单只从属于一个用户

一对多查询的需求：查询一个用户，与此同时查询出该用户具有的订单

1.5.2 一对多查询的语句

对应的sql语句：

select * from user;

select * from orders where uid=查询出用户的id;

查询的结果如下：

1.5.3 修改User实体

public class Order {

    private int id;
    private Date ordertime;
    private double total;

    //代表当前订单从属于哪一个客户
    private User user;
}

public class User {
    
    private int id;
    private String username;
    private String password;
    private Date birthday;
    //代表当前用户具备哪些订单
    private List<Order> orderList;
}

1.5.4 创建UserMapper接口

List<User> findUserAndOrderAll();

1.5.5 使用注解配置Mapper

public interface UserMapper {
  /**
     * 一对多查询
     * @return
     */
    @Select("select * from user")
    @Results({
            @Result(id = true, column = "id", property = "id"),
            @Result(column = "username", property = "username"),
            @Result(column = "password", property = "password"),
            @Result(
                    property = "orderList",
                    column = "id",//SELECT * FROM USER 查询结果的id作为查询条件参数
                    javaType = List.class,
                    many = @Many(select = "cn.wbslz.mapper.OrderMapper.findByUid")
            )
       }
    )
    public List<User> findUserAndOrderAll();
}

public interface OrderMapper {
    @Select("select * from orders where uid=#{uid}")
    List<Order> findByUid(int uid);

}

1.5.6 测试结果

    @Test
    public void findUserAndOrderAll(){
        List<User> userAndOrderAll = mapper.findUserAndOrderAll();
        for (User user:userAndOrderAll){
            System.out.println(user);
        }
    }

1.6 多对多查询

1.6.1 多对多查询的模型

用户表和角色表的关系为，一个用户有多个角色，一个角色被多个用户使用

多对多查询的需求：查询用户同时查询出该用户的所有角色

1.6.2 多对多查询的语句

对应的sql语句：

select * from user;

select * from role r,user_role ur where r.id=ur.role_id and ur.user_id=用户的id

查询的结果如下：

1.6.3 创建Role实体，修改User实体

public class User {
    private int id;
    private String username;
    private String password;
    private Date birthday;
    //代表当前用户具备哪些订单
    private List<Order> orderList;
    //代表当前用户具备哪些角色
    private List<Role> roleList;
}

public class Role {

    private int id;
    private String rolename;

}

1.6.4 添加UserMapper接口方法

List<User> findUserAndRoleAll();

1.6.5 使用注解配置Mapper

public interface UserMapper {
     /**
     * 多对多查询
     * @return
     */
    @Select("SELECT * FROM USER")
    @Results({
            @Result(id = true,column = "id",property = "id"),
            @Result(column = "username",property = "username"),
            @Result(column = "password",property = "password"),
            @Result(
                    property = "roleList",
                    column = "id",//SELECT * FROM USER 查询结果的id作为查询条件参数
                    javaType = List.class,
                    many = @Many(select = "cn.wbslz.mapper.RoleMapper.findByUid")
            )
    })
    public List<User> findUserAndRoleAll();



public interface RoleMapper {
    @Select("select * from role r,user_role ur where r.id=ur.role_id and ur.user_id=#{uid}")
    List<Role> findByUid(int uid);
}

1.6.6 测试结果

@Test
    public void findUserAndRoleAll(){
        List<User> userAndRoleAll = mapper.findUserAndRoleAll();
        for (User user:userAndRoleAll){
            System.out.println(user);
        }
    }

SSM框架整合

1.1 原始方式整合

1.准备工作

2.创建Maven工程

3.导入Maven坐标

<dependencies>
        <!--数据库驱动和连接池-->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.15</version>
        </dependency>
        <dependency>
            <groupId>com.mchange</groupId>
            <artifactId>c3p0</artifactId>
            <version>0.9.5.2</version>
            <type>jar</type>
            <scope>compile</scope>
        </dependency>
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid</artifactId>
            <version>1.0.9</version>
        </dependency>

        <!--测试-->
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
            <scope>test</scope>
        </dependency>

        <!--jstl-->
        <dependency>
            <groupId>jstl</groupId>
            <artifactId>jstl</artifactId>
            <version>1.2</version>
        </dependency>

        <!--spring相关-->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>5.0.5.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-test</artifactId>
            <version>5.0.5.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-web</artifactId>
            <version>5.0.5.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
            <version>5.0.5.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-jdbc</artifactId>
            <version>5.0.5.RELEASE</version>
        </dependency>

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-tx</artifactId>
            <version>5.0.5.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-jdbc</artifactId>
            <version>5.0.5.RELEASE</version>
            <scope>compile</scope>
        </dependency>

        <!--Servlet和jsp-->
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>javax.servlet-api</artifactId>
            <version>3.0.1</version>
            <scope>provided</scope>
        </dependency>
        <dependency>
            <groupId>javax.servlet.jsp</groupId>
            <artifactId>javax.servlet.jsp-api</artifactId>
            <version>2.2.1</version>
            <scope>provided</scope>
        </dependency>

        <!--json-->
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-core</artifactId>
            <version>2.9.8</version>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-databind</artifactId>
            <version>2.9.8</version>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-annotations</artifactId>
            <version>2.9.8</version>
        </dependency>

        <!--文件上传和下载-->
        <dependency>
            <groupId>commons-fileupload</groupId>
            <artifactId>commons-fileupload</artifactId>
            <version>1.3.1</version>
        </dependency>
        <dependency>
            <groupId>commons-io</groupId>
            <artifactId>commons-io</artifactId>
            <version>2.3</version>
        </dependency>

        <!--日志-->
        <dependency>
            <groupId>log4j</groupId>
            <artifactId>log4j</artifactId>
            <version>1.2.17</version>
        </dependency>

        <!--mybatis-->
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
            <version>3.4.6</version>
        </dependency>
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis-spring</artifactId>
            <version>1.3.1</version>
        </dependency>
        <!--自定义类型处理相关-->
        <dependency>
            <groupId>com.github.pagehelper</groupId>
            <artifactId>pagehelper</artifactId>
            <version>3.7.5</version>
        </dependency>
        <dependency>
            <groupId>com.github.jsqlparser</groupId>
            <artifactId>jsqlparser</artifactId>
            <version>1.0</version>
        </dependency>

        <dependency>
            <groupId>org.aspectj</groupId>
            <artifactId>aspectjweaver</artifactId>
            <version>1.8.14</version>
        </dependency>

    </dependencies>


    <build>
        <resources>
            <resource>
                <directory>src/main</directory>
                <includes>
                    <include>**/*.xml</include>
                </includes>
            </resource>
        </resources>


        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.3</version>
                <configuration>
                    <source>11</source>
                    <target>11</target>
                </configuration>
            </plugin>
        </plugins>

    </build>

4.编写实体类

public class Account {
    private int id;
    private String name;
    private double money;
    //省略getter和setter方法
}

5.编写Mapper接口

public interface AccountMapper {
    //保存账户数据
    void save(Account account);
    //查询账户数据
    List<Account> findAll();
}

6.编写Service接口

public interface AccountService {
    void save(Account account); //保存账户数据
    List<Account> findAll(); //查询账户数据
}

7.编写Service接口实现

@Service("accountService")
public class AccountServiceImpl implements AccountService {
    public void save(Account account) {
        SqlSession sqlSession = MyBatisUtils.openSession();
        AccountMapper accountMapper = sqlSession.getMapper(AccountMapper.class);
        accountMapper.save(account);
        sqlSession.commit();
        sqlSession.close();
    }
    public List<Account> findAll() {
        SqlSession sqlSession = MyBatisUtils.openSession();
        AccountMapper accountMapper = sqlSession.getMapper(AccountMapper.class);
        return accountMapper.findAll();
    }
}

8.编写Controller

@Controller
@RequestMapping("/account")
public class AccountController {
    @Autowired
    private AccountService accountService;
    @RequestMapping("/save")
    @ResponseBody
    public String save(Account account){
        accountService.save(account);
        return "save success";
    }
    @RequestMapping("/findAll")
    public ModelAndView findAll(){
        ModelAndView modelAndView = new ModelAndView();
        modelAndView.setViewName("accountList");
        modelAndView.addObject("accountList",accountService.findAll());
        return modelAndView;
    }
}

9.编写添加页面

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>Title</title>
</head>
<body>
    <h1>保存账户信息表单</h1>
    <form action="${pageContext.request.contextPath}/account/save" method="post">
        用户名称<input type="text" name="name"><br/>
        账户金额<input type="text" name="money"><br/>
        <input type="submit" value="保存"><br/>
    </form>
</body>
</html>

10.编写列表页面

<table border="1">
    <tr>
        <th>账户id</th>
        <th>账户名称</th>
        <th>账户金额</th>
    </tr>
    <c:forEach items="${accountList}" var="account">
        <tr>
            <td>${account.id}</td>
            <td>${account.name}</td>
            <td>${account.money}</td>
        </tr>
    </c:forEach>
</table>

11.编写相应配置文件(看源码)

•Spring配置文件：applicationContext.xml

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

•SprngMVC配置文件：spring-mvc.xml

<!--组件扫描 主要扫描controller-->
    <context:component-scan base-package="cn.wbslz.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>

    <!--开放静态资源访问权限-->
    <mvc:default-servlet-handler></mvc:default-servlet-handler>

•MyBatis映射文件：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="cn.wbslz.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>

•MyBatis核心文件：sqlMapConfig.xml

    <!--原始方式整合时所用文件-->
    
    <!--通过properties标签加载外部properties文件-->
    <properties resource="jdbc.properties"></properties>
    
    <!--定义别名-->
    <typeAliases>
        <!--<typeAlias type="cn.wbslz.domain.Account" alias="account"></typeAlias>-->
        <!--扫包方式 当前包下实体名称首字母小写-->
        <package name="cn.wbslz.domain"/>
    </typeAliases>

    <!--数据源环境-->
    <environments default="developement">
        <environment id="developement">
            <transactionManager type="JDBC"></transactionManager>
            <dataSource type="POOLED">
                <property name="driver" value="${jdbc.driver}"/>
                <property name="url" value="${jdbc.url}"/>
                <property name="username" value="${jdbc.username}"/>
                <property name="password" value="${jdbc.password}"/>
            </dataSource>
        </environment>
    </environments>

    <!--加载映射-->
    <mappers>
       <!-- <mapper resource="cn/wbslz/mapper/AccountMapper.xml"></mapper>-->
        <!--扫包方式-->
        <package name="cn/wbslz/mapper"/>
    </mappers>

•数据库连接信息文件：jdbc.properties

jdbc.driver=com.mysql.cj.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/ssm?serverTimezone=GMT%2B8&useSSL=false
jdbc.username=root
jdbc.password=密码

•Web.xml文件：web.xml

    <!--spring监听器-->
    <context-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>classpath:applicationContext.xml</param-value>
    </context-param>
    <listener>
        <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
    </listener>

    <!--SpringMVC的前端控制器-->
    <servlet>
        <servlet-name>DispatcherServlet</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
        <init-param>
            <param-name>contextConfigLocation</param-name>
            <param-value>classpath:spring-mvc.xml</param-value>
        </init-param>
        <load-on-startup>1</load-on-startup>
    </servlet>
    <servlet-mapping>
        <servlet-name>DispatcherServlet</servlet-name>
        <url-pattern>/</url-pattern>
    </servlet-mapping>

    <!--乱码过滤器-->
    <filter>
        <filter-name>CharacterEncodingFilter</filter-name>
        <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
        <init-param>
            <param-name>encoding</param-name>
            <param-value>UTF-8</param-value>
        </init-param>
    </filter>
    <filter-mapping>
        <filter-name>CharacterEncodingFilter</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>

•日志文件：[log4j.xml](

12.测试添加账户

13.测试账户列表

1.2 Spring整合MyBatis

1.整合思路

2.将SqlSessionFactory配置到Spring容器中

<!--加载jdbc.properties-->
<context:property-placeholder location="classpath:jdbc.properties"/>
<!--配置数据源-->
<bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
    <property name="driverClass" value="${jdbc.driver}"/>
    <property name="jdbcUrl" value="${jdbc.url}"/>
    <property name="user" value="${jdbc.username}"/>
    <property name="password" value="${jdbc.password}"/>
</bean>
<!--配置MyBatis的SqlSessionFactory-->
<bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
    <property name="dataSource" ref="dataSource"/>
    <property name="configLocation" value="classpath:sqlMapConfig.xml"/>
</bean>

3.扫描Mapper，让Spring容器产生Mapper实现类

<!--配置Mapper扫描-->
<bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
    <property name="basePackage" value="cn.wbslz.mapper"/>
</bean>

4.配置声明式事务控制

    <!--配置声明式事务控制-->
    <!--平台事务管理器-->
    <bean id="transacionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
        <property name="dataSource" ref="dataSource"/>
    </bean>
    <!--配置事务增强-->
    <tx:advice id="txAdvice" transaction-manager="transacionManager">
        <tx:attributes>
            <tx:method name="*"/>
        </tx:attributes>
    </tx:advice>
    <!--事务aop织入-->
    <aop:config>
        <aop:pointcut id="txPointcut" expression="execution(* cn.wbslz.service.impl.*.*(..))"/>
        <aop:advisor advice-ref="txAdvice" pointcut-ref="txPointcut"/>
    </aop:config>

5.修改Service实现类代码

@Service("accountService")
public class AccountServiceImpl implements AccountService {

    @Autowired
    private AccountMapper accountMapper;

    public void save(Account account) {
        accountMapper.save(account);
    }
    public List<Account> findAll() {
        return accountMapper.findAll();
    }
}

6.完成

（[点开我的主页系统的学习java]）