寫在前面

本文的出發點在於：本人師傅比較NB，在專案中資料庫操作用的MyBatis，需要涉及到多對多的操作，問師傅多對多是否需要建立關聯實體，師傅說了句“低階的可以建，高階的不需要”，於是乎，為了挑戰難度，在專案中最終以不建立關聯實體解決了多對多的操作問題。於是空閒的時間自己用spring-mvc 4、MyBatis 、MySQL 、Maven從零搭建起一個 簡單的demo，一是為了從頭到尾鞏固理解，二是為了留著以後忘記了可以查閱，三是也希望能幫助到一些像我這樣菜鳥級別的人。此片文章可能非常長，我寫的步驟也算很細了，NB的人肯定認為很累贅，不過重在分享！

環境工具

• 作業系統：Windows 7
• 開發工具：Intellij IDEA 14
• 資料庫連線：Navicat 11 Premium
• 介面測試：Postman

demo要完成的功能

• 對學生student的操作：學生學號必須唯一
  
  • 新增學生資訊；
  • 修改學生資訊；
  • 按學號查詢學生資訊；
  • 查詢所有學生資訊(不載入所選教師資訊)；
  • 查詢所有學生資訊(同時載入所選教師資訊);
• 對教師teacher的操作：教師工號必須唯一
  
  • 新增教師資訊；
  • 修改教師資訊；
  • 按工號查詢教師資訊；
  • 查詢所有教師資訊(不載入所教學生資訊)；
  • 查詢所有教師資訊(同時載入所教學生資訊);
• 對關聯表student_teacher的操作：學生選授課教師
  
  • 學生選擇多個授課教師，關聯資訊插入關聯表中

demo依賴jar包說明

• junit-3.8.1.jar：用於單元測試；
• spring-jdbc-4.1.6.RELEASE.jar：事務管理；
• spring-webmvc-4.1.6.RELEASE.jar：spring-mvc 4必須；
• spring-aspects-4.1.6.RELEASE.jar：面向切面程式設計；
• mybatis-3.2.8.jar：MyBatis必須；
• mybatis-spring-1.2.2.jar：MyBatis整合spring所需；
• commons-dbcp-1.4.jar：資料庫連線池；
• slf4j-log4j12-1.7.7.jar：列印日誌；
• servlet-api-2.5.jar：servlet容器所需
• fastjson-1.1.36.jar：json資料轉換工具；
• jackson-databind-2.3.3.jar：序列化類為json格式資料所需；
• mysql-connector-java-5.1.32.jar：java連線MySQL資料庫驅動包

開發步驟

第一步：新建資料庫

1.ER圖：

2.student表：

3.teacher表：

4.關聯表student_teacher：

5.關聯表增加外來鍵與student和teacher關聯：

第二步：新建Maven工程

1.新建maven webapp工程：

2.填寫maven座標：

3.新建完成的工程：

4.配置maven：
(1).maven home directory：maven解壓後所在的路徑；
(2).usere settings file:maven conf目錄下的setting檔案，具體配置略；
(3).local repository：本地maven倉庫所在的目錄，用於存放jar

第三步：搭建專案結構

新建entity包、dao包、service包、impl包、controller包，結構按需自定義

第四步：配置開發環境引數

修改專案編碼：三處均為 “UTF-8”

第五步：增加所有jar依賴到pom.xml

新增專案所需的所有jar的maven座標：

<dependencies>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>3.8.1</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-jdbc</artifactId>
            <version>4.1.6.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
            <version>4.1.6.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-aspects</artifactId>
            <version>4.1.6.RELEASE</version>
        </dependency>
        <!-- mybatis -->
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
            <version>3.2.8</version>
        </dependency>
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis-spring</artifactId>
            <version>1.2.2</version>
        </dependency>
        <dependency>
            <groupId>commons-dbcp</groupId>
            <artifactId>commons-dbcp</artifactId>
            <version>1.4</version>
        </dependency>
        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-log4j12</artifactId>
            <version>1.7.7</version>
        </dependency>
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>servlet-api</artifactId>
            <version>2.5</version>
            <scope>provided</scope>
        </dependency>
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>fastjson</artifactId>
            <version>1.1.36</version>
        </dependency>

        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-databind</artifactId>
            <version>2.3.3</version>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.32</version>
            <scope>runtime</scope>
        </dependency>
    </dependencies>

第六步：配置application.development.properties和applicationContext.xml

1. application.development.properties：資料庫連線引數以及資料庫連線池引數；

#mysql database setting
jdbc.driver=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://127.0.0.1/mybatis-demo?useUnicode=true&characterEncoding=utf-8
jdbc.username=user
jdbc.password=123456

#connection pool settings
jdbc.pool.minIdle=3
jdbc.pool.maxIdle=5
jdbc.pool.maxActive=15
jdbc.pool.maxWait=120000

2 . applicationContext.xml：spring容器核心配置

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:context="http://www.springframework.org/schema/context"
       xmlns:tx="http://www.springframework.org/schema/tx"
       xmlns:p="http://www.springframework.org/schema/p"
       xmlns="http://www.springframework.org/schema/beans" xmlns:aop="http://www.springframework.org/schema/aop"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.2.xsd
        http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.2.xsd

        http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.2.xsd
        http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd"
       default-lazy-init="true">
    <description>Spring公共配置</description>
    <!-- 該 BeanPostProcessor 將自動對標註 @Autowired 的 Bean 進行注入 -->
    <context:annotation-config/>
    <!-- 使用annotation 自動註冊bean, 並保證@Required、@Autowired的屬性被注入 -->
    <context:component-scan base-package="com.xiaolong.demo"/>

    <!-- MyBatis配置 -->
    <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
        <property name="dataSource" ref="dataSource"/>
        <!-- 自動掃描entity目錄, 省掉Configuration.xml裡的手工配置 -->
        <property name="typeAliasesPackage" value="com.xiaolong.demo"/>
        <!-- 顯式指定Mapper檔案位置 -->
        <property name="mapperLocations" value="classpath:/mybatis/*Mapper.xml"/>
    </bean>
    <!-- 掃描basePackage下所有以@MyBatisRepository標識的 介面 -->
    <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
        <property name="basePackage" value="com.xiaolong.demo.dao"/>
        <property name="annotationClass"
                  value="com.xiaolong.demo.dao.MyBatisRepository"/>
    </bean>

    <!-- 使用annotation定義事務 -->
    <tx:annotation-driven proxy-target-class="true"/>
    <bean id="transactionManager" name="transactionManager"
          class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
        <property name="dataSource">
            <ref bean="dataSource"/>
        </property>
    </bean>
    <tx:advice id="transactionAdvice" transaction-manager="transactionManager">
        <!--<tx:attributes>-->
            <!--<tx:method name="*" propagation="REQUIRED" rollback-for="Exception"/>-->
        <!--</tx:attributes>-->
    </tx:advice>
    <aop:config proxy-target-class="true">
        <aop:pointcut id="transactionPointcut"
                      expression="execution(* com.xiaolong.demo.service.impl.*.*(..))"/>
        <aop:advisor pointcut-ref="transactionPointcut"
                     advice-ref="transactionAdvice"/>
    </aop:config>

    <!-- local development環境 -->
    <beans profile="development">
        <context:property-placeholder
                ignore-resource-not-found="true"
                location="classpath*:/application.development.properties"/>

        <bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource">
            <property name="driverClassName" value="${jdbc.driver}"/>
            <property name="url" value="${jdbc.url}"/>
            <property name="username" value="${jdbc.username}"/>
            <property name="password" value="${jdbc.password}"/>

            <property name="maxActive">
                <value>${jdbc.pool.maxActive}</value>
            </property>
            <property name="maxIdle">
                <value>${jdbc.pool.maxIdle}</value>
            </property>
            <property name="minIdle">
                <value>${jdbc.pool.minIdle}</value>
            </property>
            <property name="maxWait">
                <value>${jdbc.pool.maxWait}</value>
            </property>
        </bean>
        <bean id="studentService" class="com.xiaolong.demo.service.impl.StudentServiceImpl" />
        <bean id="teacherService" class="com.xiaolong.demo.service.impl.TeacherServiceImpl" />
    </beans>
</beans>

第七步：配置spring-mvc.xml

<?xml version="1.0" encoding="UTF-8"?>
<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"
       xmlns="http://www.springframework.org/schema/beans"
       xsi:schemaLocation="http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.2.xsd
        http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.2.xsd
        http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.2.xsd">

    <!-- 自動掃描且只掃描@Controller -->
    <context:component-scan base-package="com.xiaolong.demo" use-default-filters="false">
        <context:include-filter type="annotation" expression="org.springframework.stereotype.Controller"/>
        <context:include-filter type="annotation"
                                expression="org.springframework.web.bind.annotation.ControllerAdvice"/>
    </context:component-scan>

    <!--<context:property-placeholder location="/WEB-INF/*.properties"/>-->

    <mvc:annotation-driven>
        <mvc:message-converters register-defaults="true">
            <!-- 將StringHttpMessageConverter的預設編碼設為UTF-8 -->
            <bean class="org.springframework.http.converter.StringHttpMessageConverter">
                <constructor-arg value="UTF-8"/>
            </bean>
        </mvc:message-converters>
    </mvc:annotation-driven>
</beans>

第七步：新建實體Student和Teacher

Student實體：

public class Student {
    private Integer id;                 //id
    private String name;                //姓名
    private String number;              //學號,保證唯一
    private String gender;              //性別
    private Integer age;                //年齡
    private List<Teacher> teachers;     //授課老師集合
    ..........省略get、set............
  }

Teacher實體：

public class Teacher {
    private Integer id;                 //id
    private String name;                //姓名
    private String number;              //工號,保證唯一
    private String gender;              //性別
    private Integer age;                //年齡
    private List<Student> students;     //所教學生集合
    ............省略get、set方法.....................   
 }

第八步：新建StudentMyBatisDao介面

在此之前需要先寫個註解類MyBatisRepository

@Retention(RetentionPolicy.RUNTIME)
@Target({ElementType.TYPE})
public @interface MyBatisRepository {
}

然後新建StudentMyBatisDao介面

@MyBatisRepository
public interface StudentMyBatisDao {
    int addStudent(Student student);

    int updateStudent(Student student);

    Student findStudentByNumber(String number);

    Student findStudentById(Long id);

    List<Student> findAll();

    List<Student> findAllWithTeachers();

    int selectTeachers(Long studentId, List<Long> teacherIds);
}

第九步：編寫MyBatis的StudentMapper.xml

說明：這裡我使用了查詢結果的繼承關係，當不需要查詢列表是resultMap就寫studentMap，當需要將教師資訊同時載入時返回的resultMap就是studentTeacherMap。另外，多對多在插入關聯表的時候我使用的是批量插入，用了foreach，param2代表第二個集合引數

<?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">
<!-- namespace必須指向Dao介面 -->
<mapper namespace="com.xiaolong.demo.dao.StudentMyBatisDao">
    <!--查詢結果不包含app列表-->
    <resultMap id="studentMap" type="com.xiaolong.demo.entity.Student">
        <id column="id" property="id" jdbcType="BIGINT"/>

        <result column="name" property="name" jdbcType="VARCHAR"/>
        <result column="number" property="number" jdbcType="VARCHAR"/>
        <result column="gender" property="gender" jdbcType="VARCHAR"/>
        <result column="age" property="age" jdbcType="INTEGER"/>
    </resultMap>
    <!--查詢的時候將教師列表一起查詢出來-->
    <resultMap id="studentTeacherMap" type="com.xiaolong.demo.entity.Student"
               extends="studentMap">
        <collection property="teachers" ofType="com.xiaolong.demo.entity.Teacher">
            <id property="id" column="t_id" jdbcType="BIGINT"/>

            <result property="name" column="t_name" jdbcType="VARCHAR"/>
            <result property="number" column="t_number" jdbcType="VARCHAR"/>
            <result property="gender" column="t_gender" jdbcType="VARCHAR"/>
            <result property="age" column="t_age" jdbcType="INTEGER"/>
        </collection>
    </resultMap>


    <sql id="columns">
        id,name,number,gender,age
    </sql>

    <select id="findStudentByNumber" resultMap="studentMap" parameterType="java.lang.String">
        SELECT
        <include refid="columns"/>
        FROM student
        WHERE number=#{0}
    </select>

    <select id="findStudentById" resultMap="studentTeacherMap" parameterType="java.lang.Long">
        SELECT
        s.id,s.name,s.number,s.gender,s.age,

        t.id as t_id,t.name as t_name,t.number as t_number,t.gender as t_gender,t.age as t_age
        FROM
        student s LEFT JOIN student_teacher st
        ON s.id=st.s_id
        LEFT JOIN teacher t
        ON t.id=st.t_id
        WHERE s.id=#{0}
    </select>

    <select id="findAll" resultMap="studentMap">
        SELECT * FROM student
    </select>

    <select id="findAllWithTeachers" resultMap="studentTeacherMap">
        SELECT
        s.id,s.name,s.number,s.gender,s.age,

        t.id as t_id,t.name as t_name,t.number as t_number,t.gender as t_gender,t.age as t_age
        FROM
        student s LEFT JOIN student_teacher st
        ON s.id=st.s_id
        LEFT JOIN teacher t
        ON t.id=st.t_id
    </select>

    <insert id="addStudent" parameterType="com.xiaolong.demo.entity.Student">
        insert into student
        (
        name,number,gender,age
        )
        values
        (
        #{name,jdbcType=VARCHAR},#{number,jdbcType=VARCHAR},#{gender,jdbcType=VARCHAR},#{age,jdbcType=INTEGER}
        )
    </insert>
    <update id="updateStudent" parameterType="com.xiaolong.demo.entity.Student">
        update student
        <set>
            <if test="name != null">
                name = #{name,jdbcType=VARCHAR},
            </if>
            <if test="number != null">
                number = #{number,jdbcType=VARCHAR},
            </if>
            <if test="gender != null">
                gender = #{gender,jdbcType=VARCHAR},
            </if>
            <if test="age != null">
                age = #{age,jdbcType=INTEGER},
            </if>
        </set>
        where id=#{id,jdbcType=BIGINT}
    </update>
    <!--/*這種方式使用批量插入*/-->
    <insert id="selectTeachers">

        INSERT INTO student_teacher
        (s_id,t_id)
        VALUES
        <foreach collection="param2" item="id" separator=",">
            (#{0}, #{id})
        </foreach>

    </insert>
</mapper> 

第十步：編寫StudentService介面

功能包括:對學生的增刪改查以及學生選擇教師

public interface StudentService {
    public void addStudent(Student student) throws Exception;

    public void updateStudent(Student student) throws Exception;

    public Student findStudentByNumber(String number);

    public List<Student> findAll();

    public List<Student> findAllWithTeachers();

    public void selectTeachers(Long studentId,List<Long> teacherIds)throws Exception;
}

第十一步：編寫StudentServiceImpl實現類

在新增和修改是我手動判斷了學號是否重複

package com.xiaolong.demo.service.impl;

import com.alibaba.fastjson.JSONObject;
import com.xiaolong.demo.dao.StudentMyBatisDao;
import com.xiaolong.demo.entity.Student;
import com.xiaolong.demo.entity.Teacher;
import com.xiaolong.demo.service.StudentService;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;
import org.springframework.transaction.annotation.Transactional;

import java.util.List;

/**
 * Created by xiaolong.zhu on 2015/6/4.
 */
@SuppressWarnings("ALL")
@Transactional
@Component
public class StudentServiceImpl implements StudentService {
    private static final Logger logger = LoggerFactory.getLogger(StudentServiceImpl.class);
    @Autowired
    private StudentMyBatisDao studentMyBatisDao;

    @Override
    public void addStudent(Student student) throws Exception {
        logger.info("新增學生資訊{}", JSONObject.toJSONString(student));
        Student another = studentMyBatisDao.findStudentByNumber(student.getNumber());
        if (another != null && another.getId() != student.getId())
            throw new Exception("引數異常，number重複");
        int result = studentMyBatisDao.addStudent(student);
        if (result != 1)
            throw new Exception("新增學生資訊失敗");
    }

    @Override
    public void updateStudent(Student student) throws Exception {
        logger.info("修改學生資訊{}", JSONObject.toJSONString(student));
        if (student.getId() == null)
            throw new Exception("引數異常，id為null");
        Student another = studentMyBatisDao.findStudentByNumber(student.getNumber());
        if (another != null && another.getId() != student.getId())
            throw new Exception("引數異常，number重複");
        int result = studentMyBatisDao.updateStudent(student);
        if (result != 1)
            throw new Exception("修改學生資訊失敗");
    }

    @Override
    public Student findStudentByNumber(String number) {
        logger.info("通過學號{}查詢學生資訊", number);
        Student student = studentMyBatisDao.findStudentByNumber(number);
        return student;
    }

    @Override
    public List<Student> findAll() {
        logger.info("查詢所有學生資訊");
        return studentMyBatisDao.findAll();
    }

    @Override
    public List<Student> findAllWithTeachers() {
        logger.info("查詢所有學生資訊及授課老師");
        return studentMyBatisDao.findAllWithTeachers();
    }

    @Override
    public void selectTeachers(Long studentId, List<Long> teacherIds) throws Exception {
        logger.info("學生{}選擇授課老師{}", studentId, teacherIds.toArray());
        Student student = studentMyBatisDao.findStudentById(studentId);
        for (Teacher teacher : student.getTeachers()) {
            if (teacher != null) {
                if (teacherIds.contains(teacher.getId()))
                    throw new Exception("引數異常,該學生" + studentId + "已經選擇了此教師" + teacher.getId() + "，不允許重複操作");
            }
        }
        int result = studentMyBatisDao.selectTeachers(studentId, teacherIds);
        if (result != teacherIds.size())
            throw new Exception("引數異常，教師id錯誤");
    }
}

在完成StudentServiceImpl之後，為了在Controller中能用@Autowired自動注入，需要將StudentServiceImpl在spring容器中註冊，見applicationContext.xml

第十二步：編寫StudentController類

說明：由於用的spring mvc 4，所以@ResponseBody就不用在寫了，它已經寫在了註解類@RestController中了。另外，ip是獲取客戶端真是ip，若使用了代理，就從header中取得，未使用代理，就使用request.getRemoteHost()得到。

package com.xiaolong.demo.controller;

import com.alibaba.fastjson.JSONObject;
import com.xiaolong.demo.entity.Student;
import com.xiaolong.demo.service.StudentService;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.HttpStatus;
import org.springframework.http.MediaType;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.*;

import javax.servlet.http.HttpServletRequest;
import java.util.List;


/**
 * Created by xiaolong.zhu on 2015/6/4.
 */
@SuppressWarnings("SpringJavaAutowiringInspection")
@RestController
@RequestMapping(value = "/demo/", consumes = {MediaType.ALL_VALUE})
public class StudentController {
    private static final Logger logger = LoggerFactory.getLogger(StudentController.class);

    @Autowired
    private StudentService studentService;

    @RequestMapping(value = "student", method = RequestMethod.POST, consumes = {MediaType.APPLICATION_JSON_VALUE})
    public ResponseEntity addStudent(@RequestBody Student student, HttpServletRequest request) {
        String ip = request.getHeader("X-Forwarded-For");
        if (ip == null)
            ip = request.getRemoteHost();
        logger.info("ip {} 正新增新的學生資訊{}", ip, JSONObject.toJSONString(student));
        try {
            studentService.addStudent(student);
            return new ResponseEntity(null, HttpStatus.OK);
        } catch (Exception e) {
            e.printStackTrace();
            logger.info(e.getMessage());
            JSONObject error = new JSONObject();
            error.put("error", e.getMessage());
            return new ResponseEntity(error, HttpStatus.BAD_REQUEST);
        }
    }

    @RequestMapping(value = "student", method = RequestMethod.PUT, consumes = {MediaType.APPLICATION_JSON_VALUE})
    public ResponseEntity updateStudent(@RequestBody Student student, HttpServletRequest request) {
        String ip = request.getHeader("X-Forwarded-For");
        if (ip == null)
            ip = request.getRemoteHost();
        logger.info("ip {} 正修改學生資訊{}", ip, JSONObject.toJSONString(student));
        try {
            studentService.updateStudent(student);
            return new ResponseEntity(null, HttpStatus.OK);
        } catch (Exception e) {
            e.printStackTrace();
            logger.info(e.getMessage());
            JSONObject error = new JSONObject();
            error.put("error", e.getMessage());
            return new ResponseEntity(error, HttpStatus.BAD_REQUEST);
        }
    }

    @RequestMapping(value = "student/{number}", method = RequestMethod.GET, produces = {MediaType.APPLICATION_JSON_VALUE})
    public ResponseEntity findByNumber(@PathVariable("number") String number,
                                       HttpServletRequest request) {
        String ip = request.getHeader("X-Forwarded-For");
        if (ip == null)
            ip = request.getRemoteHost();
        logger.info("ip {} 正通過學號{}獲取學生資訊", ip, number);
        Student student = studentService.findStudentByNumber(number);
        return new ResponseEntity(student, HttpStatus.OK);
    }


    @RequestMapping(value = "students", method = RequestMethod.GET, produces = {MediaType.APPLICATION_JSON_VALUE})
    public ResponseEntity findAll(HttpServletRequest request) {
        String ip = request.getHeader("X-Forwarded-For");
        if (ip == null)
            ip = request.getRemoteHost();
        logger.info("ip {} 獲取所有學生資訊", ip);
        List<Student> students = studentService.findAll();
        return new ResponseEntity(students, HttpStatus.OK);
    }

    @RequestMapping(value = "students/teachers", method = RequestMethod.GET, produces = {MediaType.APPLICATION_JSON_VALUE})
    public ResponseEntity findAllWithTeachers(HttpServletRequest request) {
        String ip = request.getHeader("X-Forwarded-For");
        if (ip == null)
            ip = request.getRemoteHost();
        logger.info("ip {} 獲取所有學生資訊以及其授課老師", ip);
        List<Student> students = studentService.findAllWithTeachers();
        return new ResponseEntity(students, HttpStatus.OK);
    }

    @RequestMapping(value = "student/{id}/teachers", method = RequestMethod.POST, consumes = {MediaType.APPLICATION_JSON_VALUE})
    public ResponseEntity selectTeachers(@PathVariable("id") Long studentId,
                                         @RequestBody JSONObject ids,
                                         HttpServletRequest request) {
        String ip = request.getHeader("X-Forwarded-For");
        if (ip == null)
            ip = request.getRemoteHost();
        logger.info("ip {} 學生{}選擇授課老師{}",ip,studentId,ids.toJSONString());
        try {
            studentService.selectTeachers(studentId, (List<Long>) ids.get("teacherIds"));
            return new ResponseEntity(null, HttpStatus.OK);
        }catch (Exception e) {
            e.printStackTrace();
            logger.info(e.getMessage());
            JSONObject error = new JSONObject();
            error.put("error", e.getMessage());
            <