springboot 整合mybatis_springboot drop table if exists-优快云博客

本文链接：https://blog.youkuaiyun.com/sinat_31089473/article/details/106206938

1. 引入mybatis starter

<dependency>
      <groupId>org.mybatis.spring.boot</groupId>
      <artifactId>mybatis-spring-boot-starter</artifactId>
      <version>2.1.2</version>
</dependency>

引入druid 数据源

<!--引入druid-->
<!-- https://mvnrepository.com/artifact/com.alibaba/druid -->
<dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>druid</artifactId>
    <version>1.1.8</version>
</dependency>

pom.xml

<?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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.2.7.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.atguigu</groupId>
    <artifactId>spring-boot-06-data-mybatis</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>spring-boot-06-data-mybatis</name>
    <description>Demo project for Spring Boot</description>

    <properties>
        <java.version>1.8</java.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-jdbc</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>2.1.2</version>
        </dependency>

        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <scope>runtime</scope>
        </dependency>
        <!--引入druid-->
        <!-- https://mvnrepository.com/artifact/com.alibaba/druid -->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid</artifactId>
            <version>1.1.8</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/log4j/log4j -->
        <!--<dependency>-->
            <!--<groupId>log4j</groupId>-->
            <!--<artifactId>log4j</artifactId>-->
            <!--<version>1.2.17</version>-->
        <!--</dependency>-->

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
            <exclusions>
                <exclusion>
                    <groupId>org.junit.vintage</groupId>
                    <artifactId>junit-vintage-engine</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>

application.yml

这里使用的是虚拟机docker容器中的MySQL数据库

spring:
  datasource:
    #   数据源基本配置
    username: root
    password: 111111
    driver-class-name: com.mysql.jdbc.Driver
    url: jdbc:mysql://192.168.1.8:3309/mybatis
    type: com.alibaba.druid.pool.DruidDataSource
    #   数据源其他配置
    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，去掉后监控界面sql无法统计，'wall'用于防火墙
    filters: stat,wall,log4j2
    maxPoolPreparedStatementPerConnectionSize: 20
    useGlobalDataSourceStat: true
    connectionProperties: druid.stat.mergeSql=true;druid.stat.slowSqlMillis=500

#    initialization-mode: always
#    schema:
#      - classpath:sql/department.sql
#      - classpath:sql/employee.sql
mybatis:
  config-location: classpath:mybatis/mybatis-config.xml
  mapper-locations: classpath:mybatis/mapper/EmployeeMapper.xml

2. 整合druid数据源，配置数据源相关属性

package com.atguigu.springboot.config;

import com.alibaba.druid.pool.DruidDataSource;
import com.alibaba.druid.support.http.StatViewServlet;
import com.alibaba.druid.support.http.WebStatFilter;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.boot.web.servlet.FilterRegistrationBean;
import org.springframework.boot.web.servlet.ServletRegistrationBean;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

import javax.sql.DataSource;
import java.util.Arrays;
import java.util.HashMap;
import java.util.Map;

@Configuration
public class DruidConfig {
    @ConfigurationProperties(prefix = "spring.datasource")
    @Bean
    public DataSource druid(){
        return  new DruidDataSource();
    }

    //配置Druid的监控
    //1、配置一个管理后台的Servlet
    @Bean
    public ServletRegistrationBean statViewServlet(){
        ServletRegistrationBean bean = new ServletRegistrationBean(new StatViewServlet(), "/druid/*");
        Map<String,String> initParams = new HashMap<>();

        initParams.put("loginUsername","admin");
        initParams.put("loginPassword","123456");
        initParams.put("allow","");//默认就是允许所有访问
        initParams.put("deny","192.168.15.21");

        bean.setInitParameters(initParams);
        return bean;
    }


    //2、配置一个web监控的filter
    @Bean
    public FilterRegistrationBean webStatFilter(){
        FilterRegistrationBean bean = new FilterRegistrationBean();
        bean.setFilter(new WebStatFilter());

        Map<String,String> initParams = new HashMap<>();
        initParams.put("exclusions","*.js,*.css,/druid/*");

        bean.setInitParameters(initParams);

        bean.setUrlPatterns(Arrays.asList("/*"));

        return  bean;
    }
}

访问localhost:8080/druid,有sql监控和web应用监控

3. 给数据库建表

运行建表语句

department.sql

/*
Navicat MySQL Data Transfer

Source Server         : 本地
Source Server Version : 50528
Source Host           : 127.0.0.1:3306
Source Database       : restful_crud

Target Server Type    : MYSQL
Target Server Version : 50528
File Encoding         : 65001

Date: 2018-03-05 10:41:40
*/

SET FOREIGN_KEY_CHECKS=0;

-- ----------------------------
-- Table structure for department
-- ----------------------------
DROP TABLE IF EXISTS `department`;
CREATE TABLE `department` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `departmentName` varchar(255) DEFAULT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=1 DEFAULT CHARSET=utf8;

employee.sql

/*
Navicat MySQL Data Transfer

Source Server         : 本地
Source Server Version : 50528
Source Host           : 127.0.0.1:3306
Source Database       : restful_crud

Target Server Type    : MYSQL
Target Server Version : 50528
File Encoding         : 65001

Date: 2018-03-05 10:41:40
*/

SET FOREIGN_KEY_CHECKS=0;

-- ----------------------------
-- Table structure for department
-- ----------------------------
DROP TABLE IF EXISTS `department`;
CREATE TABLE `department` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `departmentName` varchar(255) DEFAULT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=1 DEFAULT CHARSET=utf8;

application.yml 中的相关建表配置

#    initialization-mode: always
#    schema:
#      - classpath:sql/department.sql
#      - classpath:sql/employee.sql

启动项目，可以看到数据库中已有两张表

4. 创建javabean

使用javabean来封装表的属性

package com.atguigu.springboot.bean;

public class Department {
    private Integer id;
    private String departmentName;

    public Integer getId() {
        return id;
    }

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

    public String getDepartmentName() {
        return departmentName;
    }

    public void setDepartmentName(String departmentName) {
        this.departmentName = departmentName;
    }
}

package com.atguigu.springboot.bean;

public class Employee {

    private Integer id;
    private String lastName;
    private Integer gender;
    private String email;
    private Integer dId;

    public Integer getId() {
        return id;
    }

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

    public String getLastName() {
        return lastName;
    }

    public void setLastName(String lastName) {
        this.lastName = lastName;
    }

    public Integer getGender() {
        return gender;
    }

    public void setGender(Integer gender) {
        this.gender = gender;
    }

    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }

    public Integer getdId() {
        return dId;
    }

    public void setdId(Integer dId) {
        this.dId = dId;
    }
}

5. 使用mybatis对数据库进行增删改查（注解版）

package com.atguigu.springboot.mapper;


import com.atguigu.springboot.bean.Department;
import org.apache.ibatis.annotations.*;

//指定这是一个操作数据库的mapper 也可以使用MapperScan
//@Mapper
public interface DepartmentMapper {

    @Select("select * from department where id=#{id}")
    public Department getDeptById(Integer id);

    @Delete("delete from department where id=#{id}")
    public int deleteDeptById(Integer id);

    @Update("update department set departmentName=#{departmentName} where id=#{id}")
    public int updateDepartment(Department department);

    @Options(useGeneratedKeys = true,keyProperty = "id")
    @Insert("insert into department(departmentName) values(#{departmentName}) ")
    public int insertDepartment(Department department);
}


package com.atguigu.springboot.controller;

import com.atguigu.springboot.bean.Department;
import com.atguigu.springboot.bean.Employee;
import com.atguigu.springboot.mapper.DepartmentMapper;
import com.atguigu.springboot.mapper.EmployeeMapper;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class DeptController {

    @Autowired
    DepartmentMapper departmentMapper;

    @GetMapping("/dept/{id}")
    public Department getDepartment(@PathVariable("id") Integer id){
        return departmentMapper.getDeptById(id);
    }

    @GetMapping("/dept")
    public Department insertDept(Department department){
        departmentMapper.insertDepartment(department);
        return department;
    }


}

插入一条数据

查询数据

不写配置文件的情况下，可以自定义mybatis的配置规则，来开启驼峰命名（数据库中的列名与Javabean中的不一致）

package com.atguigu.springboot.config;

import org.apache.ibatis.session.Configuration;
import org.mybatis.spring.boot.autoconfigure.ConfigurationCustomizer;
import org.springframework.context.annotation.Bean;

//使用这种方式来自定义mybatis的驼峰命名规则，只需要给容器中添加一个ConfigurationCustomizer组件
@org.springframework.context.annotation.Configuration
public class MybatisConfig {

    @Bean
    public ConfigurationCustomizer configurationCustomizer(){
        return new ConfigurationCustomizer() {
            @Override
            public void customize(Configuration configuration) {
                //开启驼峰命名法
                configuration.setMapUnderscoreToCamelCase(true);
            }
        };
    }
}

可以使用mapperscan批量扫描所有的mapper，这样departmentmapper.java就不用标注@mapper注解

package com.atguigu.springboot;

import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

//使用mapperscan批量扫描所有的mapper
@MapperScan(value = "com.atguigu.springboot.mapper")
@SpringBootApplication
public class SpringBoot06DataMybatisApplication {

    public static void main(String[] args) {
        SpringApplication.run(SpringBoot06DataMybatisApplication.class, args);
    }

}

6. 使用mybatis对数据库进行增删改查（配置文件版）

package com.atguigu.springboot.mapper;

import com.atguigu.springboot.bean.Employee;
import org.apache.ibatis.annotations.Mapper;

//使用@Mapper或者@MapperScan将接口扫描装配到容器中
public interface EmployeeMapper {

    public Employee getEmpById(Integer id);

    public void insertEmp(Employee employee);
}

编写mybatis的全局配置文件和mapper映射文件（注：在namespace上进行接口绑定全类名）

<?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>
    <settings>
        <setting name="mapUnderscoreToCamelCase" value="true"/>
    </settings>
</configuration>

<?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.atguigu.springboot.mapper.EmployeeMapper">

    <select id="getEmpById" resultType="com.atguigu.springboot.bean.Employee">
        select * from employee where id=#{id}
    </select>

    <insert id="insertEmp" parameterType="com.atguigu.springboot.bean.Employee">
        insert into employee (lastName,email,gender,d_id) values(#{lastName},#{email},#{gender},#{dId})
    </insert>
</mapper>

在application.yml指定mybatis全局配置文件和mapper映射文件的位置

mybatis:
  config-location: classpath:mybatis/mybatis-config.xml
  mapper-locations: classpath:mybatis/mapper/EmployeeMapper.xml

package com.atguigu.springboot.controller;

import com.atguigu.springboot.bean.Employee;
import com.atguigu.springboot.mapper.EmployeeMapper;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class EmpController {

    @Autowired
    EmployeeMapper employeeMapper;

    @GetMapping("/emp/{id}")
    public Employee getEmpById(@PathVariable("id") Integer id){
        System.out.println("aaa");
        return employeeMapper.getEmpById(id);
    }
}

测试

mybatis的全局配置文件中添加驼峰命名法

<settings>
    <setting name="mapUnderscoreToCamelCase" value="true"/>
</settings>

注解版和配置文件可以混合使用

注：