SSM整合、环境配置以及基础综合测试

准备：创建maven项目以及项目框架准备

在这里插入图片描述

SSM整合简介

介绍:

SSM(Spring+SpringMVC+MyBatis) 整合，就是三个框架协同开发。
Spring整合Mybatis就是将Mybatis核心配置文件当中数据源的配置、事务处理、以及工厂的配置，Mapper接口的实现类等交给Spring管理。即spring.xml
Spring整合SpringMVC，就是在web.xml当中添加监听器，当服务启动，监听触发，监听器执行了Spring的核心配置文件，核心配置文件被加载。即springmvc.xml

整合核心步骤：

Spring基础框架单独运行
SpringMVC框架单独运行
Spring整合SpringMVC框架
Spring整合Mybatis框架

添加依赖和配置文件

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>com.etime</groupId>
    <artifactId>day13</artifactId>
    <version>1.0-SNAPSHOT</version>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <maven.compiler.source>8</maven.compiler.source>
        <maven.compiler.target>8</maven.compiler.target>
        <spring-version>5.2.5.RELEASE</spring-version>
        <mybatis-version>3.4.6</mybatis-version>
    </properties>
    <dependencies>
        <!--mybatis相关包-->
        <!--mysql的驱动包-->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.11</version>
            <scope>runtime</scope>
        </dependency>
        <!--mybatis核心-->
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
            <version>${mybatis-version}</version>
        </dependency>
        <!--连接池-->
        <dependency>
            <groupId>com.mchange</groupId>
            <artifactId>c3p0</artifactId>
            <version>0.9.5.2</version>
        </dependency>
        <!--junit-->
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
            <scope>test</scope>
        </dependency>
        <!--日志包-->
        <dependency>
            <groupId>log4j</groupId>
            <artifactId>log4j</artifactId>
            <version>1.2.17</version>
        </dependency>
        <!--分页插件-->
        <dependency>
            <groupId>com.github.pagehelper</groupId>
            <artifactId>pagehelper</artifactId>
            <version>5.1.10</version>
        </dependency>

        <!--spring相关的-->
        <!--springIOC包-->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>${spring-version}</version>
        </dependency>
        <!--jdbc-->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-jdbc</artifactId>
            <version>${spring-version}</version>
        </dependency>
        <!--织入器包：-->
        <dependency>
            <groupId>org.aspectj</groupId>
            <artifactId>aspectjweaver</artifactId>
            <version>1.8.7</version>
        </dependency>

        <!--springmvc依赖：-->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
            <version>${spring-version}</version>
        </dependency>
        <!--解析器包-->
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-databind</artifactId>
            <version>2.9.9</version>
        </dependency>
        <!--文件上传-->
        <dependency>
            <groupId>commons-fileupload</groupId>
            <artifactId>commons-fileupload</artifactId>
            <version>1.3.1</version>
        </dependency>

        <!--spring整合mybatis-->
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis-spring</artifactId>
            <version>1.3.2</version>
        </dependency>
        <!--spring整合junit-->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-test</artifactId>
            <version>${spring-version}</version>
        </dependency>

        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>1.18.16</version>
        </dependency>
    </dependencies>

</project>

jdbc.properties：与数据库建立连接的密码驱动等的属性配置文件

jdbc.driver=com.mysql.cj.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/db_418?useUnicode=true&characterEncoding=utf-8&useSSL=false&serverTimezone=UTC
jdbc.username=root
jdbc.password=h123456

spring.xml配置文件配置扫描包

<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:mvc="http://www.springframework.org/schema/mvc"
       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/mvc
        http://www.springframework.org/schema/mvc/spring-mvc.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">
    <context:component-scan base-package="com.etime.service"></context:component-scan>
</beans>

新建实体类Student

package com.etime.pojo;

import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;

//注解注入无参构造函数
@NoArgsConstructor
//注解注入全参构造函数
@AllArgsConstructor
//注解注入get,set等方法
@Data
public class Student {
    private int sid;
    private String sname;
    private int cid;
}

创建接口StudentService.java:查询所有学生信息

package com.etime.service;

import com.etime.pojo.Student;

import java.util.List;

public interface StudentService {
    List<Student> getAllStudent();
}

创建StudentService.java接口的实现类StudentServiceImpl.java并继承StudentService且实现里面的方法getAllStudent

package com.etime.service.impl;

import com.etime.pojo.Student;
import com.etime.service.StudentService;
import org.springframework.stereotype.Service;

import java.util.List;

@Service
public class StudentServiceImpl implements StudentService {
    @Override
    public List<Student> getAllStudent() {
        System.out.println("这是service实现类里面的方法");
        return null;
    }
}

测试：测试通过spring的配置是否可行

package com.etime.test;

import com.etime.service.StudentService;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;

//通过@RunWith注解的方式加载注入SpringJunit4ClalssRunner.class文件对spring进行测试
@RunWith(SpringJUnit4ClassRunner.class)
//通过注解@ContextConfiguration注解加载文件spring.xml
@ContextConfiguration("classpath:spring.xml")
public class SsmTest {

    //使用自动注入注解@Autowired对接口StudentService进行注入
    @Autowired
    private StudentService studentService;

    //使用@Test单元注解的方式对实现层的方法调用
    @Test
    public void t01(){
        studentService.getAllStudent();
    }
}

单独测试service结果是spring的单独测试下面将对它进行整合：如下的测试结果表名确实是通过spring.xml配置文件可以测试当前接口实现类里面的方法

在这里插入图片描述

在web.xml中配置核心控制器（DispatcherServlet）:通过web.xml中配置核心控制器控制加载springmvc的配置文件，加载web.xml同时也加载springmvc.xml文件

<!--配置前端控制器： -->
<!--    将配置文件springmvc.xml文件整合到项目中当web.xml被加载的同时，springmvc.xml也同样被控制器内进行加载拿到配置文件内的内容-->
    <servlet>
        <servlet-name>DispatcherServlet</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
        <!--加载springmvc的配置文件：-->
        <init-param>
            <param-name>contextConfigLocation</param-name>
            <param-value>classpath:springmvc.xml</param-value>
        </init-param>
        <!--设置加载时机： -->
        <load-on-startup>1</load-on-startup>
    </servlet>

    <!-- 设置Servlet的映射路径-->
    <servlet-mapping>
        <servlet-name>DispatcherServlet</servlet-name>
        <url-pattern>/</url-pattern>
    </servlet-mapping>

创建springmvc核心配置文件：配置扫描控制层的处理文件，以及处理器，但是后期用了前后端分离的模式来讲解，所以其实，配置视图解析器的但是没有用到。

<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:mvc="http://www.springframework.org/schema/mvc"
       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/mvc
        http://www.springframework.org/schema/mvc/spring-mvc.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">

    <!--配置注解扫描器-->
<!--    目的是通过扫描器能找到控制层包下的所有文件，然后根据文件对其进行其它操作-->
    <context:component-scan base-package="com.etime.controller"></context:component-scan>
    <!--处理器配置-->
    <mvc:annotation-driven></mvc:annotation-driven>
    <!--配置视图解析器：-->
    <bean  class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="prefix" value="/"/>
        <property name="suffix" value=".jsp"/>
    </bean>
</beans>

创建控制器整理数据，对数据进行简单处理

package com.etime.controller;

import com.etime.pojo.Student;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;

@Controller
@RequestMapping("/student")
public class StudentController {

    @RequestMapping("t02")
    @ResponseBody
    public Student test(){
        return new Student(1,"mchh",2);
    }
}

这里测试工具我使用Apifox进行接口测试：如果想要使用该工具的，大家可以去该路径下我有写在哪可以下载，以及使用：

https://blog.csdn.net/m0_56245143/article/details/130270652?spm=1001.2014.3001.5501

运行结果：

在这里插入图片描述

整合Spring 和 SpringMVC:web.xml中添加监听器的方式当在加载的web.xml的时候就能将所需要加载的配置加载上，使用servletContext的监听器，是在该项目第一次被访问的时候就加载的，监听到的时候就对该文件的其它配置进行加载

在web.xml中进行配置：

    <context-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>classpath:spring.xml</param-value>
    </context-param>
    <!--配置了一个监听器: ServletContext-->
    <listener>
        <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
    </listener>

修改service实现类方法代码及控制器代码并测试：准备一些简单测试数据对进行测试，因为目前所做的还是为了后面整合ssm做准备的。

在StudentServiceImpl.java中进行修改

package com.etime.service.impl;

import com.etime.pojo.Student;
import com.etime.service.StudentService;
import org.springframework.stereotype.Service;

import java.util.ArrayList;
import java.util.List;

@Service
public class StudentServiceImpl implements StudentService {
    @Override
    public List<Student> getAllStudent() {
        //准备多个学生数据信息进行测试
        Student student1= new Student(1,"cc",2);
        Student student2 = new Student(2,"mc",3);
        Student student3 = new Student(3,"mm",4);
        List<Student> list = new ArrayList<>();
        list.add(student1);
        list.add(student2);
        list.add(student3);
        return list;
    }
}

对控制层也进行微量的调节，获取到service返回的数据

对StudentController.java进行修改：

package com.etime.controller;

import com.etime.pojo.Student;
import com.etime.service.StudentService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;

import java.util.List;

@Controller
@RequestMapping("/student")
public class StudentController {
    
    //本来如果没有用注解的情况下，如果要对service的数据进行访问时，就只能进行对StudentService类进行创建新对象
    //可以使用@Autowired注解的方式对service进行引入
    @Autowired
    private StudentService studentService;

    @RequestMapping("t02")
    @ResponseBody
    public List<Student> test(){
        return studentService.getAllStudent();
    }
}

运行结果：

在这里插入图片描述

该次测试将打通数据访问层将mybatis也整合进来：
编写数据访问层的接口

StudentMapper.java

package com.etime.mapper;

import com.etime.pojo.Student;

import java.util.List;

public interface StudentMapper {
    List<Student> getAllStudent();
}

编写mybatis映射配置文件：这里有两种方式，一种使用配置文件的方式，另一种方式就是使用纯注解的方式进行数据访问层的操作。我这里采用的方式是直接使用配置文件的方式：

如图所示的创建StudentMappe.xml文件以及添加修改数据：

在这里插入图片描述

<?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.etime.mapper.StudentMapper">
    <select id="getAllStudent" resultType="Student">
        select * from student
    </select>
</mapper>

将Spring和mybatis配置进行整合

准备连接数据的配置属性文件，注意根据个人即将测试的数据，修改该数据库的名称，密码和用户等

jdbc.driver=com.mysql.cj.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/db_418?useUnicode=true&characterEncoding=utf-8&useSSL=false&serverTimezone=UTC
jdbc.username=root
jdbc.password=h123456

在spring.xml中配置连接数据库，准备数据源

<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:mvc="http://www.springframework.org/schema/mvc"
       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/mvc
        http://www.springframework.org/schema/mvc/spring-mvc.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">
    <context:component-scan base-package="com.etime.service"></context:component-scan>

    <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
        <property name="basePackage" value="com.etime.mapper" />
    </bean>

    <!--数据源-->
    <context:property-placeholder location="classpath:jdbc.properties"/>
    <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>

    <!--mybatis的核心工厂对象-->
    <bean id="sessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
        <!--注入数据源-->
        <property name="dataSource" ref="dataSource"/>
        <!--别名-->
        <property name="typeAliasesPackage" value="com.etime.pojo"/>
        <!--mapper 文件的位置-->
        <property name="mapperLocations" value="classpath:com/etime/mapper/*.xml"/>
        <!--配置分页插件-->
        <property name="plugins">
            <array>
                <bean  class="com.github.pagehelper.PageInterceptor">
                    <property name="properties">
                        <value>
                            helperDialect=mysql
                            reasonable=true
                            supportMethodsArguments=true
                            params=count=countSql
                            autoRuntimeDialect=true
                        </value>
                    </property>
                </bean>
            </array>
        </property>
    </bean>
</beans>

原本是需要对spring.xml中配置的事务进行处理的使用注解权限，但是这里用不到，配置上一方用到：

<!--事务管理器平台-->
<bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
    <!--注入一个数据源-->
    <property name="dataSource" ref="dataSource"/>
</bean>

<!--开启注解式事务-->
<tx:annotation-driven transaction-manager="transactionManager"></tx:annotation-driven>

修改service实现类中的方法

StudentServiceImpl.java

package com.etime.service.impl;

import com.etime.mapper.StudentMapper;
import com.etime.pojo.Student;
import com.etime.service.StudentService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.ArrayList;
import java.util.List;

@Service
public class StudentServiceImpl implements StudentService {
    
    //使用@Autowired注解将StudentMapper接口引入
    @Autowired
    private StudentMapper studentMapper;
    
    @Override
    public List<Student> getAllStudent() {
        //准备多个学生数据信息进行测试
        return studentMapper.getAllStudent();
    }
}

启动服务进行测试整合结果：如下图的结果说明还是比较成功的打通了ssm的所有整合过程

在这里插入图片描述

SSM整合测试

使用前后端分离的技术对整合的ssm进行测试：

案例一、使用VScode、idea、js、vue3进行前后端分离的技术对查询所有学生信息进行页面展示：即简单单表操作

使用vue.global.js 、 axios.min.js 、进行页面编写

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <script src="js/axios.min.js"></script>
    <script src="js/vue.global.js"></script>
</head>
<body>
    <div id="app">
        <table>
            <tr>
                <td>学号</td>
                <td>姓名</td>
                <td>班级编号</td>
            </tr>
            <tr v-for="stu in students">
                <td>{{stu.sid}}</td>
                <td>{{stu.sname}}</td>
                <td>{{stu.cid}}</td>
            </tr>
        </table>
    </div>
    <script>
        const vueApp = Vue.createApp({
            data(){
                return{
                    students:""
                }
            },
            created(){
                axios({
                    url:"http://localhost:8080/day13_war_exploded/student/t02",
                    method:"get"
                }).then(resp => {
                    this.students = resp.data;
                });
            }
        });
        vueApp.mount("#app");
    </script>
</body>
</html>

控制层：

StudentController.java

package com.etime.controller;

import com.etime.pojo.Student;
import com.etime.service.StudentService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.CrossOrigin;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;

import java.util.List;

@Controller
@RequestMapping("/student")
//使用注解@CrossOrigin方式来解决跨域问题
@CrossOrigin
public class StudentController {

    //本来如果没有用注解的情况下，如果要对service的数据进行访问时，就只能进行对StudentService类进行创建新对象
    //可以使用@Autowired注解的方式对service进行引入
    @Autowired
    private StudentService studentService;

    @RequestMapping("t02")
    @ResponseBody
    public List<Student> test(){
        return studentService.getAllStudent();
    }
}

运行结果：由运行结果可以看出单表操作没有问题

在这里插入图片描述

接下来进行多表查询并进行分页测试，由上可知的配置中咱们是使用了mybatis分页插件的，可以利用这一工具进行数据分页到html上进行展示：

案例二：

index.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <script src="js/axios.min.js"></script>
    <script src="js/vue.global.js"></script>
</head>
<body>
    <div id="app">
        <table align="center">
            <tr>
                <td>学号</td>
                <td>姓名</td>
                <td>班级</td>
            </tr>
            <tr v-for="stu in students" align="center">
                <td>{{stu.sid}}</td>
                <td>{{stu.sname}}</td>
                <td>{{stu.classes.cname}}</td>
            </tr>
        </table>
        <div style="width: 500px;margin: auto;">
            <a href="javascript:void(0)" @click="getStudentByPage(1)">首页</a>
            <a href="javascript:void(0)" @click="getStudentByPage(prevPage)">上一页</a>
            {{pageNum}}/{{pageTotal}}
            <a href="javascript:void(0)" @click="getStudentByPage(nextPage)">下一页</a>
            <a href="javascript:void(0)" @click="getStudentByPage(pageTotal)">尾页</a>
        </div>
    </div>
    <script>
        const vueApp = Vue.createApp({
            data(){
                return{
                    students:"",
                    pageNum:"",
                    pageTotal:"",
                    prevPage:"",
                    nextPage:""
                }
            },
            methods:{
                getStudentByPage(page){
                    axios({
                    url:"http://localhost:8080/day13_war_exploded/student/t02?pageNum="+page+"&pageSize=2",
                    method:"get"
                }).then(resp => {
                    console.log(resp)
                    this.students = resp.data.list;
                    this.pageNum = resp.data.pageNum;
                    this.pageTotal = resp.data.pages;
                    this.prevPage = resp.data.prePage;
                    if(this.prevPage <= 0){
                        this.prevPage =1;
                    }
                    this.nextPage = resp.data.nextPage;
                });
                }
            },
            created(){
                this.getStudentByPage(1);
            }
        });
        vueApp.mount("#app");
    </script>
</body>
</html>

StudentController.java

package com.etime.controller;

import com.etime.pojo.Student;
import com.etime.service.StudentService;
import com.github.pagehelper.PageInfo;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.CrossOrigin;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;

import java.util.List;

@Controller
@RequestMapping("/student")
//使用注解@CrossOrigin方式来解决跨域问题
@CrossOrigin
public class StudentController {

    //本来如果没有用注解的情况下，如果要对service的数据进行访问时，就只能进行对StudentService类进行创建新对象
    //可以使用@Autowired注解的方式对service进行引入
    @Autowired
    private StudentService studentService;

    @RequestMapping("t02")
    @ResponseBody
    public PageInfo<Student> test(int pageNum,int pageSize){
        return studentService.getAllStudent(pageNum,pageSize);
    }
}

StudentService.java

package com.etime.service;

import com.etime.pojo.Student;
import com.github.pagehelper.PageInfo;


public interface StudentService {
    PageInfo<Student> getAllStudent(int pageNum,int pageSize);
}

StudentServiceImpl.java

package com.etime.service.impl;

import com.etime.mapper.StudentMapper;
import com.etime.pojo.Student;
import com.etime.service.StudentService;
import com.github.pagehelper.PageHelper;
import com.github.pagehelper.PageInfo;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.List;

@Service
public class StudentServiceImpl implements StudentService {

    //使用@Autowired注解将StudentMapper接口引入
    @Autowired
    private StudentMapper studentMapper;

    @Override
    public PageInfo<Student> getAllStudent(int pageNum, int pageSize) {
        PageHelper.startPage(pageNum,pageSize);
        List<Student> list = studentMapper.getAllStudent();
        PageInfo<Student> pageInfo = new PageInfo<>(list);
        return pageInfo;
    }
}

StudentMapper.java

package com.etime.mapper;

import com.etime.pojo.Student;

import java.util.List;

public interface StudentMapper {
   List<Student> getAllStudent();
}

StudentMapper.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.etime.mapper.StudentMapper">
    <select id="getAllStudent" resultMap="studentAndClasses">
        select * from student s,classes c where s.cid = c.cid
    </select>

    <resultMap id="studentAndClasses" type="Student">
        <id property="sid" column="sid"></id>
        <result property="sname" column="sname"></result>
        <result property="cid" column="cid"></result>
        <association property="classes" javaType="Classes">
            <id property="cid" column="cid"></id>
            <result property="cname" column="cname"></result>
        </association>
     </resultMap>
</mapper>

并在pojo中创建Classes.java班级实体类

package com.etime.pojo;

import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;

@AllArgsConstructor
@NoArgsConstructor
@Data
public class Classes {
    private int cid;
    private String cname;
}

测试结果：到目前为止基本的ssm整合对基础的查询都能成功

ntMapper">

select * from student s,classes c where s.cid = c.cid

<resultMap id="studentAndClasses" type="Student">
    <id property="sid" column="sid"></id>
    <result property="sname" column="sname"></result>
    <result property="cid" column="cid"></result>
    <association property="classes" javaType="Classes">
        <id property="cid" column="cid"></id>
        <result property="cname" column="cname"></result>
    </association>
 </resultMap>

```

并在pojo中创建Classes.java班级实体类

package com.etime.pojo;

import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;

@AllArgsConstructor
@NoArgsConstructor
@Data
public class Classes {
    private int cid;
    private String cname;
}