SSM整合开发

SSM：SpringMVC + Spring +MyBatis

SpringMVC：视图层，用于接收页面请求，显示处理结果
Spring：业务层，管理service，dao，工具类对象
Mybatis：持久层，访问数据库

用户发起请求—>SpringMVC接收—>Spring中调用的Service对象处理事务—>MyBatis处理数据

1、整合的思路

在进行整合时，有两个容器对象
1、SpringMVC容器，管理Controller控制器对象
2、Spring容器，管理Service，Dao，工具类对象
我们要把使用的对象交给合适的容器去创建，管理。
把Controller还有web开发相关对象交给SpringMVC容器，将这些web使用的对象写在springmvc配置文件中。
把Service，Dao对象定义在Spring的配置文件中，让Spring管理这些对象。

两个容器之间的关系：
SpringMVC容器是Spring的子容器，类似于Java中的子父类关系——子类可以访问父类的数据。
即在子容器SpringMVC中的Controller可以访问父容器Spring中的Service对象，就可以实现Controller使用Service对象。

2、整合的步骤

使用之前创建好的mybatis数据库，使用student表

1、创建maven web项目

2、加入依赖

springmvc，spring，mybatis三个框架的依赖，jackson依赖，mysql驱动，druid连接池，jsp,servlet依赖

<dependencies>
    <dependency>
        <groupId>junit</groupId>
        <artifactId>junit</artifactId>
        <version>4.11</version>
        <scope>test</scope>
    </dependency>
    <!-- servlet依赖-->
    <dependency>
        <groupId>javax.servlet</groupId>
        <artifactId>javax.servlet-api</artifactId>
        <version>3.1.0</version>
        <scope>provided</scope>
    </dependency>
    <!-- jsp依赖-->
    <dependency>
        <groupId>javax.servlet.jsp</groupId>
        <artifactId>jsp-api</artifactId>
        <version>2.2.1-b03</version>
        <scope>provided</scope>
    </dependency>
    <!--springmvc依赖-->
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-webmvc</artifactId>
        <version>5.2.5.RELEASE</version>
    </dependency>
    <!--事务-->
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-tx</artifactId>
        <version>5.2.5.RELEASE</version>
    </dependency>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-jdbc</artifactId>
        <version>5.2.5.RELEASE</version>
    </dependency>
    <!--jackson-->
    <dependency>
        <groupId>com.fasterxml.jackson.core</groupId>
        <artifactId>jackson-core</artifactId>
        <version>2.9.0</version>
    </dependency>
    <dependency>
        <groupId>com.fasterxml.jackson.core</groupId>
        <artifactId>jackson-databind</artifactId>
        <version>2.9.0</version>
    </dependency>
    <!--mybatis-->
    <dependency>
        <groupId>org.mybatis</groupId>
        <artifactId>mybatis-spring</artifactId>
        <version>1.3.1</version>
    </dependency>
    <dependency>
        <groupId>org.mybatis</groupId>
        <artifactId>mybatis</artifactId>
        <version>3.5.1</version>
    </dependency>
    <dependency>
        <!--mysql-->
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <version>8.0.19</version>
    </dependency>
    <!--druid-->
    <dependency>
        <groupId>com.alibaba</groupId>
        <artifactId>druid</artifactId>
        <version>1.1.12</version>
    </dependency>
</dependencies>

<build>
    <resources>
        <resource>
            <directory>src/main/java</directory><!--所在的目录-->
            <includes><!--包括目录下的.properties,.xml 文件都会扫描到-->
                <include>**/*.properties</include>
                <include>**/*.xml</include>
            </includes>
            <filtering>false</filtering>
        </resource>
    </resources>
    <plugins>
        <plugin>
            <artifactId>maven-compiler-plugin</artifactId>
            <version>3.1</version>
            <configuration>
                <source>1.8</source>
                <target>1.8</target>
            </configuration>
        </plugin>
    </plugins>
</build>

3、写web.xml

1、注册中央处理器DispatcherServlet，
目的：1、创建springmvc容器对象，才能创建Controller对象；2、创建的是Servlet，才能接收用户的请求。

2、注册监听器ContextLoaderListener，
目的：创建spring容器对象，才能创建service，dao等对象

3、注册字符集过滤器CharacterEncodingFilter，
目的：解决post请求乱码

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd"
         version="4.0">

<!--  注册中央调度器  -->
    <servlet>
        <servlet-name>myweb</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
        <init-param>
            <param-name>contextConfigLocation</param-name>
            <param-value>classpath:conf/springmvc.xml</param-value>
        </init-param>
        <load-on-startup>1</load-on-startup>
    </servlet>
    <servlet-mapping>
        <servlet-name>myweb</servlet-name>
        <url-pattern>*.do</url-pattern>
    </servlet-mapping>

<!-- 注册监听器  用于创建Spring容器   -->
    <context-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>classpath:conf/application.xml</param-value>
    </context-param>
    <listener>
        <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
    </listener>

<!--注册字符集过滤器-->
    <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>
        <init-param>
            <param-name>forceRequestEncoding</param-name>
            <param-value>true</param-value>
        </init-param>
        <init-param>
            <param-name>forceResponseEncoding</param-name>
            <param-value>true</param-value>
        </init-param>
    </filter>
    <filter-mapping>
        <filter-name>characterEncodingFilter</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>
</web-app>

4、创建包

创建controller、service、dao、bean包

5、写springmvc，spring，mybatis的配置文件

1、springmvc.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"
       xmlns:mvc="http://www.springframework.org/schema/mvc"
       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
       http://www.springframework.org/schema/mvc
       https://www.springframework.org/schema/mvc/spring-mvc.xsd">

    <!--springmvc配置文件，声明 controller和它相关的对象-->
    <context:component-scan base-package="com.zyz.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>

    <!--注解驱动-->
    <mvc:annotation-driven/>
</beans>

2、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: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">

    <!--  将数据库配置文件写入单独的文件中        -->
    <context:property-placeholder location="classpath:conf/jdbc.properties"/>
    <!--声明数据源  用于连接数据库-->
    <bean id="myDataSource" class="com.alibaba.druid.pool.DruidDataSource"
          init-method="init" destroy-method="close">
        <property name="url" value="${jdbc.url}"/>
        <property name="username" value="${jdbc.username}"/>
        <property name="password" value="${jdbc.password}"/>
        <property name="maxActive" value="${jdbc.maxActive}"/>
    </bean>

    <!--声明mybatis中的SqlSessionFactoryBean 用于创建SqlSessionFactory对象    -->
    <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
        <!-- set注入，把数据库连接池赋值给dateSource属性-->
        <property name="dataSource" ref="myDataSource"/>
        <!-- mybatis主配置文件的位置-->
        <property name="configLocation" value="classpath:conf/mybatisConfig.xml"/>
    </bean>

    <!-- 声明Dao类
         MapperScannerConfigurer:在内部调用getMapper()生成每一个接口的dao代理对象
         创建好的dao对象放在spring容器中，默认名称为 接口名首字母小写-->
    <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
        <property name="sqlSessionFactoryBeanName" value="sqlSessionFactory"/>
        <property name="basePackage" value="com.zyz.dao"/>
    </bean>

    <!--  声明service的注解@Service所在的包名位置  -->
    <context:component-scan base-package="com.zyz.service"/>

    <!--  事务配置：注解的配置或aspectj的配置  -->
</beans>

3、mybatisConfig.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>
    <!--  注册映射文件  -->
    <mappers>
        <package name="com.zyz.dao"/>
    </mappers>

</configuration>

4、jdbc.properties

jdbc.url=jdbc:mysql://localhost:3306/mybatis?serverTimezone=Asia/Shanghai
jdbc.username=root
jdbc.password=2824199842
jdbc.maxActive=20

6、编写各个包的代码

bean实体类

dao接口和mapper文件

package com.zyz.dao;

import com.zyz.bean.Employee;

import java.util.List;

public interface EmployeeDao {

    public int insertEmp(Employee employee);
    List<Employee> listAllEmps();
}

<?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.zyz.dao.EmployeeDao">
    <select id="listAllEmps" resultType="com.zyz.bean.Employee">
        select name,gender,email,dept_id deptId from employee order by id asc
    </select>

    <insert id="insertEmp">
        insert into employee(name,gender,email,dept_id) values (#{name},#{gender},#{email},#{deptId})
    </insert>
</mapper>

service及其实现类

public interface EmployeeService {
    int addEmp(Employee employee);
    List<Employee> listAllEmps();
}

@Service
public class EmployeeServiceImpl implements EmployeeService {

    // 引用类型自动注入@Autowired,@Resource    dao对象就在Spring容器中
    @Resource
    private EmployeeDao employeeDao;
    @Override
    public int addEmp(Employee employee) {
        return employeeDao.insertEmp(employee);
    }

    @Override
    public List<Employee> listAllEmps() {
        return employeeDao.listAllEmps();
    }
}

controller

@Controller
@RequestMapping("/employee")
public class EmployeeController {

    @Resource
    private EmployeeService employeeService;

    // 员工注册
    @RequestMapping("/addEmployee.do")
    public ModelAndView addStudent(Employee employee){
        ModelAndView modelAndView = new ModelAndView();
        String tips = "注册失败";
        // 调用service
        int num = employeeService.addEmp(employee);
        if(num>0){
            // 注册成功
            tips="注册成功！";
        }
        // 添加数据
        modelAndView.addObject("tips",tips);
        // 指定结果页面
        modelAndView.setViewName("result");
        return modelAndView;
    }

    // 员工查询
    @RequestMapping("/listAllEmps.do")
    @ResponseBody
    public List<Employee> listAllEmp(){
        return employeeService.listAllEmps();
    }
}

7、编写页面

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%String basePath = request.getContextPath()+"/";%>
<html>
<head>
    <title>首页</title>
    <base href="<%=basePath%>"/>

</head>
<body>
    <div align="center">
        <img src="images/yy.jpg" style="width: 200px;height: 200px">
        <table>
            <tr>
                <td><a href="addEmployee.jsp">注册员工</a></td>
            </tr>
            <tr>
                <td><a href="listAllEmployee.jsp">浏览员工</a></td>
            </tr>
        </table>
    </div>
</body>
</html>

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%String basePath = request.getContextPath() + "/";%>
<html>
<head>
    <title>注册员工</title>
    <base href="<%=basePath%>"/>
</head>
<body>
<div align="center">
    <form action="employee/addEmployee.do" method="post">
        <table>
            <tr>
                <td>姓名：</td>
                <td><input type="text" name="name"/></td>
            </tr>
            <tr>
                <td>性别：</td>
                <td><input type="radio" name="gender" value="1"/>男&nbsp;&nbsp;&nbsp;
                    <input type="radio" name="gender" value="0"/>女
                </td>
            </tr>
            <tr>
                <td>电子邮箱：</td>
                <td><input type="text" name="email"/></td>
            </tr>
            <tr>
                <td>部门编号：</td>
                <td><input type="number" name="deptId"/></td>
            </tr>
            <tr>
                <td>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</td>
                <td><input type="submit" value="注册"/></td>
            </tr>
        </table>
    </form>
</div>
</body>
</html>

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%String basePath = request.getContextPath() + "/";%>
<html>
<head>
    <title>查询所有员工</title>
    <base href="<%=basePath%>"/>
    <script type="text/javascript" src="js/jquery-3.4.1.js"></script>
    <script type="text/javascript">
        $(function () {
            // 当前页面dom对象加载后，立即执行
            loadEmpData();
        })
        function loadEmpData() {
            $.ajax({
                url: "employee/listAllEmps.do",
                type: "get",
                dataType: "json",
                success: function (data) {
                    // alert(data);
                    // 清除旧数据
                    $("#info").html("");
                    $.each(data, function (k, v) {
                        $("#info").append("<tr>")
                            .append("<td>" + v.name + "</td>")
                            .append("<td>" + v.gender + "</td>")
                            .append("<td>" + v.email + "</td>")
                            .append("<td>" + v.deptId + "</td>")
                    })
                }
            })
        }
    </script>
</head>
<body>
<div align="center">
    <table border="1" cellspacing="0">
        <tr>
            <th>姓名</th>
            <th>性别</th>
            <th>电子邮箱</th>
            <th>部门编号</th>
        </tr>
        <tr>
            <tbody id="info"></tbody>
        </tr>
    </table>
</div>
</body>
</html>

项目整体结构：