1）创建Spring Boot项目并集成Mybatis。使用XML配置的方式实现完整的学生信息管理模块，包括学生、班级等信息的新增、修改、删除、查询等功能。

答案:

1. application.properties 配置数据库

spring.datasource.test1.driver-class-name=com.mysql.cj.jdbc.Driver
spring.datasource.test1.jdbc-url=jdbc:mysql://127.0.0.1:3306/test?useSSL=false&serverTimezone=UTC
spring.datasource.test1.username=root
spring.datasource.test1.password=123456
spring.datasource.test2.driver-class-name=com.mysql.cj.jdbc.Driver
spring.datasource.test2.jdbc-url=jdbc:mysql://127.0.0.1:3306/dp_database?useSSL=false&serverTimezone=UTC
spring.datasource.test2.username=root
spring.datasource.test2.password=123456

2. mybatis多数据源配置

DataSource1Config.java

package com.example.demo.config;

import org.apache.ibatis.session.SqlSessionFactory;
import org.mybatis.spring.SqlSessionFactoryBean;
import org.mybatis.spring.SqlSessionTemplate;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.boot.jdbc.DataSourceBuilder;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Primary;
import org.springframework.core.io.support.PathMatchingResourcePatternResolver;
import org.springframework.jdbc.datasource.DataSourceTransactionManager;

import javax.sql.DataSource;

@Configuration
@MapperScan(basePackages = "com.example.demo.mapper.test1", sqlSessionFactoryRef = "test1SqlSessionFactory")
public class DataSource1Config {

    @Primary
    @Bean(name = "test1DataSource")
    @ConfigurationProperties(prefix = "spring.datasource.test1")
    public DataSource dataSource() {
        return DataSourceBuilder.create().build();
    }

    @Primary
    @Bean(name = "test1SqlSessionFactory")
    public SqlSessionFactory sqlSessionFactory(@Qualifier("test1DataSource") DataSource dataSource) throws Exception {
        SqlSessionFactoryBean bean = new SqlSessionFactoryBean();
        bean.setDataSource(dataSource);
        bean.setMapperLocations(new PathMatchingResourcePatternResolver().getResources("classpath*:/mapper/test1/*.xml"));
        return bean.getObject();
    }

    @Primary
    @Bean(name = "test1TransactionManager")
    public DataSourceTransactionManager transactionManager(@Qualifier("test1DataSource") DataSource dataSource) {
        return new DataSourceTransactionManager(dataSource);
    }

    @Primary
    @Bean(name = "test1SqlSessionTemplate")
    public SqlSessionTemplate sqlSessionTemplate(@Qualifier("test1SqlSessionFactory") SqlSessionFactory sqlSessionFactory) {
        return new SqlSessionTemplate(sqlSessionFactory);
    }
}

DataSource2Config.java

package com.example.demo.config;

import org.apache.ibatis.session.SqlSessionFactory;
import org.mybatis.spring.SqlSessionFactoryBean;
import org.mybatis.spring.SqlSessionTemplate;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.boot.jdbc.DataSourceBuilder;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.io.support.PathMatchingResourcePatternResolver;
import org.springframework.jdbc.datasource.DataSourceTransactionManager;

import javax.sql.DataSource;

@Configuration
@MapperScan(basePackages = "com.example.demo.mapper.test2", sqlSessionFactoryRef = "test2SqlSessionFactory")
public class DataSource2Config {

    @Bean(name = "test2DataSource")
    @ConfigurationProperties(prefix = "spring.datasource.test2")
    public DataSource dataSource() {
        return DataSourceBuilder.create().build();
    }

    @Bean(name = "test2SqlSessionFactory")
    public SqlSessionFactory sqlSessionFactory(@Qualifier("test2DataSource") DataSource dataSource) throws Exception {
        SqlSessionFactoryBean bean = new SqlSessionFactoryBean();
        bean.setDataSource(dataSource);
        bean.setMapperLocations(new PathMatchingResourcePatternResolver().getResources("classpath*:/mapper/test2/*.xml"));
        return bean.getObject();
    }

    @Bean(name = "test2TransactionManager")
    public DataSourceTransactionManager transactionManager(@Qualifier("test2DataSource") DataSource dataSource) {
        return new DataSourceTransactionManager(dataSource);
    }

    @Bean(name = "test2SqlSessionTemplate")
    public SqlSessionTemplate sqlSessionTemplate(@Qualifier("test2SqlSessionFactory") SqlSessionFactory sqlSessionFactory) {
        return new SqlSessionTemplate(sqlSessionFactory);
    }
}

3. 学生实体类 Student.java

package com.example.demo.bean;

public class Student {

    private Long id;
    private String name;
    private Integer sex;
    private Integer age;
    private Classes classes;

    public Student() {
    }

    public Student(String name, int sex, int age) {
        this.name = name;
        this.sex = sex;
        this.age = age;
    }

    @Override
    public String toString() {
        return "Student{" +
                "id=" + id +
                ", name='" + name + '\'' +
                ", sex=" + sex +
                ", age=" + age +
                '}';
    }

    public Classes getClasses() {
        return classes;
    }

    public void setClasses(Classes classes) {
        this.classes = classes;
    }

    public void setAge(Integer age) {
        this.age = age;
    }

    public void setSex(Integer sex) {
        this.sex = sex;
    }

    public Long getId() {
        return id;
    }

    public void setId(Long id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public Integer getSex() {
        return sex;
    }

    public void setSex(int sex) {
        this.sex = sex;
    }

    public Integer getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }
}

4. StudentOneController 控制器  创建 StudentOneController 类，处理学生管理的 HTTP 请求。

package com.example.demo.controller;

import com.example.demo.bean.Student;
import com.example.demo.service.StudentOneService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.*;

@Controller
@RequestMapping("/studentsone")
public class StudentOneController {

    @Autowired
    private StudentOneService studentOneService;

    @GetMapping("/")
    public String getAllStudents(Model model) {
        model.addAttribute("students", studentOneService.listAllStudent());
        return "studentsone/list";
    }

    @GetMapping("/add")
    public String showAddForm(Model model) {
        model.addAttribute("student", new Student());
        return "studentsone/add";
    }

    @PostMapping("/add")
    public String addStudent(@ModelAttribute Student student) {
        studentOneService.insertStudent(student);
        return "redirect:/studentsone/";
    }

    @GetMapping("/edit/{id}")
    public String showEditForm(@PathVariable Long id, Model model) {
        Student student = studentOneService.getStudentById(id);
        model.addAttribute("student", student);
        return "studentsone/edit";
    }

    @PostMapping("/edit/{id}")
    public String updateStudent(@PathVariable Long id, @ModelAttribute Student student) {
        student.setId(id);
        studentOneService.updateStudent(student);
        return "redirect:/studentsone/";
    }

    @GetMapping("/delete/{id}")
    public String deleteStudent(@PathVariable Long id) {
        studentOneService.deleteStudent(id);
        return "redirect:/studentsone/";
    }

}

5. StudentOneService 服务类 创建 StudentOneService 类，用于业务逻辑处理。

package com.example.demo.service;

import com.example.demo.bean.Student;
import com.example.demo.mapper.test1.PrimaryStudentMapper;
import org.mybatis.spring.SqlSessionTemplate;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.stereotype.Service;

import java.util.List;

@Service
public class StudentOneService {



    private final PrimaryStudentMapper primaryMapper;

    @Autowired
    public StudentOneService(@Qualifier("test1SqlSessionTemplate") SqlSessionTemplate test1SqlSessionTemplate){
        this.primaryMapper = test1SqlSessionTemplate.getMapper(PrimaryStudentMapper.class);
    }


    public List<Student> listAllStudent(){
        List<Student> studentsPrimary = primaryMapper.selectAll();
        return studentsPrimary;
    }

    public Student getStudentById(Long id){
        Student student = primaryMapper.selectOne(id);
        return student;
    }

    public void insertStudent(Student student){
        primaryMapper.insert(student);
    }

    public void updateStudent(Student student){
        primaryMapper.update(student);
    }

    public void deleteStudent(Long id){
        primaryMapper.delete(id);
    }

}

6. mybatis PrimaryStudentMapper.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.example.demo.mapper.test1.PrimaryStudentMapper">
    <select id="selectAll" resultType="com.example.demo.bean.Student">
        SELECT * FROM student
    </select>
    <select id="selectOne" parameterType="Long" resultType="com.example.demo.bean.Student">
        SELECT * FROM student WHERE id = #{id}
    </select>
    <insert id="insert" parameterType="com.example.demo.bean.Student">
        INSERT INTO student (name, sex, age) values (#{name}, #{sex}, #{age})
    </insert>
    <update id="update" parameterType="com.example.demo.bean.Student">
        UPDATE student SET
            <if test="name != null">name = #{name},</if>
            <if test="sex != null">sex = #{sex},</if>
            age = #{age}
        WHERE
            id = #{id}
    </update>
    <delete id="delete" parameterType="Long">
        DELETE FROM student WHERE id = #{id}
    </delete>
    <resultMap id="StudentAndClassMap" type="com.example.demo.bean.Student">
        <id column="id" property="id" jdbcType="BIGINT"/>
        <result column="name" property="name" jdbcType="VARCHAR"/>
        <result column="sex" property="sex" jdbcType="INTEGER"/>
        <result column="age" property="age" jdbcType="INTEGER"/>
        <association property="classes" javaType="com.example.demo.bean.Classes">
            <id column="id" property="id"/>
            <result column="class_name" property="name" jdbcType="VARCHAR"/>
            <result column="memo" property="memo" jdbcType="VARCHAR"/>
        </association>
    </resultMap>
    <select id="selectStudentAndClass" parameterType="Long" resultMap="StudentAndClassMap">
        SELECT s.id,s.name,s.sex,s.age,s.class_id,c.name as class_name, c.memo
        FROM student s LEFT JOIN classes c ON s.class_id = c.id WHERE s.id = #{id}
    </select>

    <resultMap id="ClassAndStudentMap" type="com.example.demo.bean.Classes">
        <id property="id" column="id"/>
        <result property="name" column="name"/>
        <result property="memo" column="memo"/>
        <collection property="students" ofType="com.example.demo.bean.Student">
            <id property="id" column="student_id"/>
            <result property="name" column="student_name"/>
            <result property="age" column="age" />
        </collection>
    </resultMap>
    <select id="selectClassAndStudent" parameterType="Long" resultMap="ClassAndStudentMap">
        SELECT c.id,c.name,c.memo,s.id as student_id,s.name as student_name,s.age,s.sex FROM classes c
            LEFT JOIN student s on s.class_id = c.id WHERE c.id = #{id}
    </select>
    
</mapper>

7. Thymeleaf 页面  创建页面模板来展示学生列表、添加、编辑学生等功能。studentsone目录下:

list.html

<!DOCTYPE html>
<html xmlns:th="http://www.thymeleaf.org">
<head>
    <title>学生信息管理</title>
</head>
<body>
<h1>学生信息</h1>
<table>
    <thead>
    <tr>
        <th>ID</th>
        <th>姓名</th>
        <th>年龄</th>
        <th>性别</th>
        <th>操作</th>
    </tr>
    </thead>
    <tbody>
    <tr th:each="student : ${students}">
        <td th:text="${student.id}"></td>
        <td th:text="${student.name}"></td>
        <td th:text="${student.age}"></td>
        <td th:text="${student.sex}"></td>
        <td>
            <a th:href="@{/studentsone/edit/{id}(id=${student.id})}">编辑</a> |
            <a th:href="@{/studentsone/delete/{id}(id=${student.id})}">删除</a>
        </td>
    </tr>
    </tbody>
</table>
<a href="/studentsone/add">添加学生</a>
</body>
</html>

add.html

<!DOCTYPE html>
<html xmlns:th="http://www.thymeleaf.org">
<head>
    <title>添加学生</title>
</head>
<body>
<h1>添加学生</h1>
<form action="#" th:action="@{/studentsone/add}" th:object="${student}" method="post">
    <label>姓名:</label>
    <input type="text" th:field="*{name}"/><br/>
    <label>年龄:</label>
    <input type="number" th:field="*{age}"/><br/>
    <label>性别:</label>
    <input type="number" th:field="*{sex}"/><br/>
    <button type="submit">提交</button>
</form>
<a href="/studentsone/">返回</a>
</body>
</html>

edit.html

<!DOCTYPE html>
<html xmlns:th="http://www.thymeleaf.org">
<head>
    <title>编辑学生</title>
</head>
<body>
<h1>编辑学生</h1>
<form action="#" th:action="@{/studentsone/edit/{id}(id=${student.id})}" th:object="${student}" method="post">
    <label>姓名:</label>
    <input type="text" th:field="*{name}"/><br/>
    <label>年龄:</label>
    <input type="number" th:field="*{age}"/><br/>
    <label>性别:</label>
    <input type="number" th:field="*{sex}"/><br/>
    <button type="submit">提交</button>
</form>
<a href="/studentsone/">返回</a>
</body>
</html>

8.  测试  启动 Spring Boot 应用，访问：

2)  增加学生信息多条件查询功能，查询条件覆盖姓名、性别和年龄等字段。

答案：

要实现多条件查询功能，可以在 PrimaryStudentMapper 和 StudentOneService 中添加一个多条件查询方法。在 XML 配置文件中使用 <where> 标签动态生成 SQL 查询，以根据条件的有无生成相应的查询语句。

以下是详细的实现步骤：

1. 修改 PrimaryStudentMapper 接口

public interface PrimaryStudentMapper {
    List<Student> selectByConditions(Student student);
}

2. 在 PrimaryStudentMapper 的 XML 中定义 SQL 查询

    <select id="selectByCondition" resultType="com.example.demo.bean.Student">
        SELECT * FROM student
        <where>
            <if test="name != null and name != ''">
                name = #{name}
            </if>
            <if test="sex != null">
                AND sex = #{sex}
            </if>
            <if test="age != null">
                AND age = #{age}
            </if>
        </where>
    </select>

3. 修改 StudentOneService 服务层
在 StudentOneService 中增加 selectByConditions 方法，调用 PrimaryStudentMapper 的 selectByConditions 方法。
 

    public List<Student> findStudentsByCondition(Student student){
        return primaryMapper.selectByCondition(student);
    }

4. 控制器StudentOneController调用示例
在控制层可以通过传入包含条件的 Student 对象来调用 findStudentsByConditions 方法。以下是一个示例：

    @GetMapping("/search")
    public String searchStudents(
            @RequestParam(required = false) String name,
            @RequestParam(required = false) Integer sex,
            @RequestParam(required = false) Integer age,Model model){
        Student student = new Student();
        student.setName(name);
        student.setSex(sex);
        student.setAge(age);
        model.addAttribute("students", studentOneService.findStudentsByCondition(student));
        return "studentsone/list";
    }

5. 测试多条件查询
访问 /students/search 端点，可以传入不同的查询条件组合进行查询。例如：
查询姓名为 “weiz新增” 的学生：/studentsone/search?name=weiz新增