• 整合MyBatis 9


    官方文档:http://mybatis.org/spring-boot-starter/mybatis-spring-boot-autoconfigure/

    Maven仓库地址:https://mvnrepository.com/artifact/org.mybatis.spring.boot/mybatis-spring-boot-starter/2.1.1

     

     整合测试

     1、导入 MyBatis 所需要的依赖

    <dependency>
        <groupId>org.mybatis.spring.boot</groupId>
        <artifactId>mybatis-spring-boot-starter</artifactId>
        <version>2.1.1</version>
    </dependency>

    2、配置数据库连接信息(不变)

    复制代码
    spring:
      datasource:
        username: root
        password: 123456
        #?serverTimezone=UTC解决时区的报错
        url: jdbc:mysql://localhost:3306/springboot?serverTimezone=UTC&useUnicode=true&characterEncoding=utf-8
        driver-class-name: com.mysql.cj.jdbc.Driver
        type: com.alibaba.druid.pool.DruidDataSource
    
        #Spring Boot 默认是不注入这些属性值的,需要自己绑定
        #druid 数据源专有配置
        initialSize: 5
        minIdle: 5
        maxActive: 20
        maxWait: 60000
        timeBetweenEvictionRunsMillis: 60000
        minEvictableIdleTimeMillis: 300000
        validationQuery: SELECT 1 FROM DUAL
        testWhileIdle: true
        testOnBorrow: false
        testOnReturn: false
        poolPreparedStatements: true
    
        #配置监控统计拦截的filters,stat:监控统计、log4j:日志记录、wall:防御sql注入
        #如果允许时报错  java.lang.ClassNotFoundException: org.apache.log4j.Priority
        #则导入 log4j 依赖即可,Maven 地址:https://mvnrepository.com/artifact/log4j/log4j
        filters: stat,wall,log4j
        maxPoolPreparedStatementPerConnectionSize: 20
        useGlobalDataSourceStat: true
        connectionProperties: druid.stat.mergeSql=true;druid.stat.slowSqlMillis=500
    复制代码

    3、测试数据库是否连接成功!

    4、创建实体类,导入 Lombok!

    Department.java

    复制代码
    package com.kuang.pojo;
    
    import lombok.AllArgsConstructor;
    import lombok.Data;
    import lombok.NoArgsConstructor;
    
    @Data
    @NoArgsConstructor
    @AllArgsConstructor
    public class Department {
    
        private Integer id;
        private String departmentName;
    
    }
    复制代码

    5、创建mapper目录以及对应的 Mapper 接口

    DepartmentMapper.java

    复制代码
    //@Mapper : 表示本类是一个 MyBatis 的 Mapper
    @Mapper
    @Repository
    public interface DepartmentMapper {
    
        // 获取所有部门信息
        List<Department> getDepartments();
    
        // 通过id获得部门
        Department getDepartment(Integer id);
    
    }
    复制代码

    6、对应的Mapper映射文件

    DepartmentMapper.xml

    复制代码
    <?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.kuang.mapper.DepartmentMapper">
    
        <select id="getDepartments" resultType="Department">
           select * from department;
        </select>
    
        <select id="getDepartment" resultType="Department" parameterType="int">
           select * from department where id = #{id};
        </select>
    
    </mapper>
    复制代码

    7、maven配置资源过滤问题

    复制代码
    <resources>
        <resource>
            <directory>src/main/java</directory>
            <includes>
                <include>**/*.xml</include>
            </includes>
            <filtering>true</filtering>
        </resource>
    </resources>
    复制代码

    8、编写部门的 DepartmentController 进行测试!

    复制代码
    @RestController
    public class DepartmentController {
        
        @Autowired
        DepartmentMapper departmentMapper;
        
        // 查询全部部门
        @GetMapping("/getDepartments")
        public List<Department> getDepartments(){
            return departmentMapper.getDepartments();
        }
    
        // 查询全部部门
        @GetMapping("/getDepartment/{id}")
        public Department getDepartment(@PathVariable("id") Integer id){
            return departmentMapper.getDepartment(id);
        }
        
    }
    复制代码

    启动项目访问进行测试!

    我们增加一个员工类再测试下,为之后做准备

    1、新建一个pojo类 Employee ;

    复制代码
    @Data
    @AllArgsConstructor
    @NoArgsConstructor
    public class Employee {
    
        private Integer id;
        private String lastName;
        private String email;
        //1 male, 0 female
        private Integer gender;
        private Integer department;
        private Date birth;
    
        private Department eDepartment; // 冗余设计
    
    }
    复制代码

    2、新建一个 EmployeeMapper 接口

    复制代码
    //@Mapper : 表示本类是一个 MyBatis 的 Mapper
    @Mapper
    @Repository
    public interface EmployeeMapper {
    
        // 获取所有员工信息
        List<Employee> getEmployees();
    
        // 新增一个员工
        int save(Employee employee);
    
        // 通过id获得员工信息
        Employee get(Integer id);
    
        // 通过id删除员工
        int delete(Integer id);
    
    }
    复制代码

    3、编写 EmployeeMapper.xml 配置文件

    复制代码
    <?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.kuang.mapper.EmployeeMapper">
    
        <resultMap id="EmployeeMap" type="Employee">
            <id property="id" column="eid"/>
            <result property="lastName" column="last_name"/>
            <result property="email" column="email"/>
            <result property="gender" column="gender"/>
            <result property="birth" column="birth"/>
            <association property="eDepartment"  javaType="Department">
                <id property="id" column="did"/>
                <result property="departmentName" column="dname"/>
            </association>
        </resultMap>
    
        <select id="getEmployees" resultMap="EmployeeMap">
            select e.id as eid,last_name,email,gender,birth,d.id as did,d.department_name as dname
            from department d,employee e
            where d.id = e.department
        </select>
    
        <insert id="save" parameterType="Employee">
            insert into employee (last_name,email,gender,department,birth)
            values (#{lastName},#{email},#{gender},#{department},#{birth});
        </insert>
    
        <select id="get" resultType="Employee">
            select * from employee where id = #{id}
        </select>
    
        <delete id="delete" parameterType="int">
            delete from employee where id = #{id}
        </delete>
    
    </mapper>
    复制代码

    4、编写EmployeeController类进行测试

    复制代码
    @RestController
    public class EmployeeController {
    
        @Autowired
        EmployeeMapper employeeMapper;
    
        // 获取所有员工信息
        @GetMapping("/getEmployees")
        public List<Employee> getEmployees(){
            return employeeMapper.getEmployees();
        }
    
        @GetMapping("/save")
        public int save(){
            Employee employee = new Employee();
            employee.setLastName("kuangshen");
            employee.setEmail("qinjiang@qq.com");
            employee.setGender(1);
            employee.setDepartment(101);
            employee.setBirth(new Date());
            return employeeMapper.save(employee);
        }
    
        // 通过id获得员工信息
        @GetMapping("/get/{id}")
        public Employee get(@PathVariable("id") Integer id){
            return employeeMapper.get(id);
        }
    
        // 通过id删除员工
        @GetMapping("/delete/{id}")
        public int delete(@PathVariable("id") Integer id){
            return employeeMapper.delete(id);
        }
    
    }
    复制代码

    测试结果完成,搞定收工!

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  • 原文地址:https://www.cnblogs.com/pengyuan192/p/13366002.html
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