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SpringBoot整合MyBatisPlus详解

目录
  • 1.什么是springboot自动装配?
  • 2.springboot注解:
  • 3.springboot整合myBATisplus实现增删改查

1.什么是springboot自动装配?

自动装配是springboot的核心,一般提到自动装配就会和springboot联系在一起。实际上 Spring Framework 早就实现了这个功能。Spring Boot 只是在其基础上,通过 SPI 的方式,做了进一步优化。

SpringBoot 定义了一javascript套接口规范,这套规范规定:SpringBoot 在启动时会扫描外部引用 jar 包中的META-INF/spring.factories文件,将文件中配置的类型信息加载到 Spring 容器(此处涉及到 JVM 类加载机制与 Spring 的容器知识),并执行类中定义的各种操作。对于外部 jar 来说,只需要按照 SpringBoot 定义的标准,就能将自己的功能装置进 SpringBoot

2.springboot注解:

@EnableAutoConfiguration:扫包范围默认当前类。

@ComponentScan(" “) 扫包范围默认当前类所在的整个包下面所有类。

扫包范围大于@EnableAutoConfiguration,@ComponentScan(” ")依赖于@EnableAutoConfiguration启动程序。

@EnableAutoConfiguration

@ComponentScan("第三方包 ")

app.run()

@SpringBootApplication 扫包范围同级包和当前包。

@SpringBootApplication 底层等同于@EnableAutoConfiguration+@ComponentScan。不扫描第三方包

3.springboot整合mybatisplus实现增删改查

1.首先导入相关依赖

   <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-boot-starter</artifactId>
            <version>3.5.1</version>
        </dependency>
        <dependency>
            <groupId>com.spring4all</groupId>
            <artifactId>swagger-spring-boot-starter</artifactId>
            <version>1.9.1.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>com.github.xiaoymin</groupId>
            <artifactId>swagger-bootstrap-ui</artifactId>
            <version>1.7.8</version>
        </dependency>

        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-Java</artifactId>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

2.创建数据表并添加数据

DROP TABLE IF EXISTS `category`;
CREATE TABLE `category`  (
  `cid` varchar(32) CHARACTER SET utf8mb3 COLLATE utf8mb3_general_ci NOT NULL,
  `cname` varchar(50) CHARACTER SET utf8mb3 COLLATE utf8mb3_general_ci NULL DEFAULT NULL,
  PRIMARY KEY (`cid`) USING BTREE
) ENGINE = InnoDB CHARACTER SET = utf8mb3 COLLATE = utf8mb3_general_ci ROW_FORMAT = DYNAMIC;

-- ----------------------------
-- Records of category
-- ----------------------------
INSERT INTO `category` VALUES ('c001', '家电');
INSERT INTO `category` VALUES ('c002', '鞋服');
INSERT INTO `category` VALUES ('c003', '化妆品');
INSERT INTO `ca开发者_Js入门tegory` VALUES ('c004', '汽车');

-- ----------------------------
-- Table structure for products
-- ----------------------------
DROP TABLE IF EXISTS `products`;
CREATE TABLE `products`  (
  `pid` varchar(32) CHARACTER SET utf8mb3 COLLATE utf8mb3_general_ci NOT NULL,
  `pname` varchar(50) CHARACTER SET utf8mb3 COLLATE utf8mb3_general_ci NULL DEFAULT NULL,
  `price` int NULL DEFAULT NULL,
  `flag` varchar(2) CHARACTER SET utf8mb3 COLLATE utf8mb3_general_ci NULL DEFAULT NULL,
  `category_id` varchar(32) CHARACTER SET utf8mb3 COLLATE utf8mb3_general_ci NULL DEFAULT NULL,
  PRIMARY KEY (`pid`) USING BTREE,
  INDEX `category_id`(`category_id`) USING BTREE,
  CONSTRAINT `products_ibfk_1` FOREIGN KEY (`category_id`) REFERENCES `category` (`cid`) ON DELETE RESTRICT ON UPDATE RESTRICT
) ENGINE = InnoDB CHARACTER SET = utf8mb3 COLLATE = utf8mb3_general_ci ROW_FORMAT = DYNAMIC;

-- ----------------------------
-- Records of products
-- ----------------------------
INSERT INTO `products` VALUES ('p001', '小\r\n米电视 机', 5000, '1', 'c001');
INSERT INTO `products` VALUES ('p002', '格\r\n力空调', 3000, '1', 'c001');
INSERT INTO `products` VALUES ('p003', '美\r\n的冰箱', 4500, '1', 'c001');
INSERT INTO `products` VALUES ('p004', '篮\r\n球鞋', 800, '1', 'c002');
INSERT INTO `products` VALUES ('p005', '运\r\n动裤', 200, '1', 'c002');
INSERT INTO `products` VALUES ('p006', 'T\r\n恤', 300, '1', 'c002');
INSERT INTO `products` VALUES ('p009', '篮球', 188, '1', 'c002');

3.在项目中创建如下目录

SpringBoot整合MyBatisPlus详解

4.在resources下创建application.propertis并配置数据源

spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver
spring.datasource.username=root
spring.datasource.password=123456
spring.datasource.url=jdbc:mysql:///springboot

#日志
mybatis.configuration.log-impl=org.apache.ibatis.logging.stdout.StdOutImpl

mybatis.mapper-locations=classpath:mapper/*.XML



5.在pojo下创建实体类

package com.azy.pojo;

import java.io.Serializable;

import com.baomidou.mybatisplus.annotation.IdType;
import com.baomidou.mybatisplus.annotation.TableField;
import com.baomidou.mybatisplus.annotation.TableId;
import com.baomidou.mybatisplus.annotation.TableName;
import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;

/**
 * products
 * @author 
 */
@Data
@AllArgsConstructor
@NoArgsConstructor
@TableName(value = "products")
public cpythonlass Products implements Serializable {
    @TableId(type = IdType.AUTO)
    private String pid;

    public Products(String pid, String pname, Integer price) {
        this.pid = pid;
        this.pname = pname;
        this.price = price;
    }

    private String pname;

    private Integer price;

    private String flag;

    private String category_id;
    @TableField(exist = false)
    private Category category;

    private static final long serialVersionUID = 1L;
}

6.在dao层下创建ProductDao这个接口,由于mybatisplus封装了单表的增删改查,所有只需继承BaseMapper这个接口就ok

package com.azy.dao;

import com.azy.pojo.Products;

import com.baomidou.mybatisplus.core.conditions.Wrapper;
import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import com.baomidou.mybatisplus.core.metadata.IPage;
import org.apache.ibatis.annotations.Param;

/**
 * @ fileName:ProductsDao
 * @ description:
 * @ author:Azy
 * @ createTime:2023/4/11 18:57
 * @ version:1.0.0
 */
public interface ProductsDao extends BaseMapper<Products> {
    IPage<Products> findPage(IPage<Products> iPage, @Param("ew") Wrapper<Products> wrapper);
}

7.在resources下面的mapper下创建ProductsDao.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.azy.dao.ProductsDao">
    <resultMap id="ProductsMap" type="com.azy.pojo.Products" autoMapping="true">
        <id property="pid" column="pid" jdbcType="VARCHAR"/>
        <result property="pname" column="pname" jdbcType="VARCHAR"/>
        <result property="price" column="price" jdbcType="INTEGER"/>
        <result property="flag" column="flag" jdbcType="VARCHAR"/>
        <result property="category_id" column="category_id" jdbcType="VARCHAR"/>
        <association property="category" javaType="com.azy.pojo.Category" autoMapping="true">
            <id column="cid" property="cid" jdbcType="VARCHAR"/>
            <result property="cname" column="cname" jdbcType="VARCHAR"/>
        </association>
    </resultMap>

    <select id="findPage" resultType="com.azy.pojo.Products" resultMap="ProductsMap">
        select *
        from products p
        join category c
        on p.category_id=c.cid
        <if test="ew!=null">
            <where>
                 ${ew.sqlSegment}
            </where>
        </if>
    </select>

</mapper>

8.在test包下的测试类中测试

package com.azy;

import com.azy.dao.ProductsDao;
import com.azy.dao.UserDao;
import com.azy.pojo.Products;
import com.azy.pojo.User;
import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import org.junit.jupiter.ap编程i.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;

import javax.annotation.Resource;
import java.util.List;

@SpringBootTest
class DemoApplicationTests {
    @Resource
    private UserDao userDao;
    @Test
    void contextLoads() {
        QueryWrapper<User> wrapper = new QueryWrapper<>();
        wrapper.likeRight("name","_z");
        wrapper.or();
        wrapper.between("age",10,20);
        wrapper.orderByDesc("age");
        wrapper.select("name","age");
        List<User> users = userDao.selectList(wrapper);
        users.forEach(System.out::println);
    }
    @Test
    public void delete(){
        System.out.println(userDao.deleteById(5));
    }
    @Test
    public void insert(){
        User user = new User();
        user.setAge(18);
        user.setName("cxk");
        user.setEmail("123@qq.com");
        System.out.println(userDao.insert(user));
    }
    @Test
    public void update(){
        User user = new User();
        user.setAge(19);
        user.setName("azy");
        user.setEmail("321@qq.com");
        user.setId(6L);
        System.out.println(userDao.updateById(user));
    }
    @Test
    public void selectById(){
        System.out.println(userDao.selectById(4));
    }
    @Test
    public void testPage(){
        Page<User> page = new Page<>(1, 3);//current:当前第几页 size:每页显示条数
        userDao.selectPage(page,null);//把查询分页的结构封装到page对象中
        System.out.println("当前页的记录"+page.getRecords());//获取当前页的记录
        System.out.println("获取总页数"+page.getPages());//获取当前页的总页数
        System.out.println("获取总条数"+page.getTotal());//获取当前页的记录
    }

//    ==============================================================
    @Resource
    private ProductsDao productsDao;
    @Test
    public void testQueryProductById(){
        System.out.println(productsDao.selectById("p008"));
    }

    @Test
    public void testDelete(){
        System.out.println(productsDao.deleteById("p008"));
    }

    @Test
    public void testInsert(){
        Products products = new Products();
        products.setPname("滑板鞋");
        products.setFlag("2");
        products.setPrice(8888);
        products.setCategory_id("c002");
        products.setPid("p009");
        System.out.println(produ编程客栈ctsDao.insert(products));
    }
    @Test
    public void testUpdate(){
        Products products = new Products();
        products.setPname("篮球");
        products.setFlag("1");
  编程客栈      products.setPrice(188);
        products.setCategory_id("c002");
        products.setPid("p009");
        System.out.println(productsDao.updateById(products));
    }
    @Test
    public void testProductsPage(){
        Page<Products> page = new Page<>(1, 3);//current:当前第几页 size:每页显示条数
        productsDao.selectPage(page,null);//把查询分页的结构封装到page对象中
        System.out.println("当前页的记录"+page.getRecords());//获取当前页的记录
        System.out.println("获取总页数"+page.getPages());//获取当前页的总页数
        System.out.println("获取总条数"+page.getTotal());//获取当前页的记录
    }
    @Test
    public void testProductsPage2(){
        Page<Products> page=new Page<>(1,3);
        QueryWrapper<Products> wrapper=new QueryWrapper<>();
        wrapper.gt("price",1000);
        productsDao.findPage(page,wrapper);
        System.out.println("当前页的记录"+page.getRecords());//获取当前页的记录
        System.out.println("获取总页数"+page.getPages());//获取当前页的记录
        System.out.println("获取总条数"+page.getTotal());//获取当前页的记录
    }
}

9.最后运行测试类

SpringBoot整合MyBatisPlus详解

测试完成

到此这篇关于SpringBoot整合mybatisplus详解的文章就介绍到这了,更多相关SpringBoot整合mybatisplus内容请搜索我们以前的文章或继续浏览下面的相关文章希望大家以后多多支持我们!

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