Springboot+MyBatis+JPA集成

梦里梦外; 2023-10-18 19:34 88阅读 0赞

##### 1. 前言 #####

Springboot最近可谓是非常的火，本人也在项目中尝到了甜头。之前一直使用Springboot+JPA，用了一段时间发现JPA不是太灵活，也有可能是我不精通JPA，总之为了多学学Springboot我决定尝试一下Springboot+MyBatis+JPA三项集成，集成过程中遇到了很多问题，但最后总算是集成成功了，现在记录一下方法。

##### 2. 实现 #####

以前用过SpringMVC，知道写xxxMapper.java接口以及xxxMapper.xml文件的辛苦，这次集成最先想到的就是先解决如何使用如何使用MyBatis Generator自动生成这些文件的问题。  
如果没接触过，可以去MyBatis Generator的[官网][Link 1]了解一下

###### 2.1 创建项目 ######

这里使用的Maven集成插件的方式，IDE使用的是IDEA  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3RpYW50YW5nXzE5ODY_size_16_color_FFFFFF_t_70]![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3RpYW50YW5nXzE5ODY_size_16_color_FFFFFF_t_70 1]![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3RpYW50YW5nXzE5ODY_size_16_color_FFFFFF_t_70 2]

###### 2.2 修改pom.xml ######

添加了Druid依赖和MyBatis Generator插件  
其他依赖请自行添加

<?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 http://maven.apache.org/xsd/maven-4.0.0.xsd">
        <modelVersion>4.0.0</modelVersion>
    
        <groupId>com.study.springboot</groupId>
        <artifactId>mybatis</artifactId>
        <version>1.0</version>
        <packaging>war</packaging>
    
        <name>demo</name>
        <description>springboot+mybatis+jpa</description>
    
        <parent>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-parent</artifactId>
            <version>1.5.9.RELEASE</version>
            <relativePath/>
        </parent>
    
        <properties>
            <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
            <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
            <java.version>1.8</java.version>
        </properties>
    
        <dependencies>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-data-jpa</artifactId>
            </dependency>
            <dependency>
                <groupId>org.mybatis.spring.boot</groupId>
                <artifactId>mybatis-spring-boot-starter</artifactId>
                <version>1.3.1</version>
            </dependency>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-web</artifactId>
            </dependency>
    
            <dependency>
                <groupId>mysql</groupId>
                <artifactId>mysql-connector-java</artifactId>
                <scope>runtime</scope>
            </dependency>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-tomcat</artifactId>
                
            </dependency>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-test</artifactId>
                <scope>test</scope>
            </dependency>
    
            
            <dependency>
                <groupId>com.alibaba</groupId>
                <artifactId>druid</artifactId>
                <version>1.1.5</version>
            </dependency>
    
        </dependencies>
    
        <build>
            <plugins>
                <plugin>
                    <groupId>org.springframework.boot</groupId>
                    <artifactId>spring-boot-maven-plugin</artifactId>
                </plugin>
    
                
                <plugin>
                    <groupId>org.mybatis.generator</groupId>
                    <artifactId>mybatis-generator-maven-plugin</artifactId>
                    <version>1.3.5</version>
                    <executions>
                        <execution>
                            <id>Generate MyBatis Artifacts</id>
                            <goals>
                                <goal>generate</goal>
                            </goals>
                        </execution>
                    </executions>
                </plugin>
            </plugins>
        </build>
    </project>

###### 2.3 配置generatorConfiguration ######

`generatorConfig.xml`放在resource文件夹下。常用配置已经注释了，请自行查看

<?xml version="1.0" encoding="UTF-8"?>
    <!DOCTYPE generatorConfiguration
            PUBLIC "-//mybatis.org//DTD MyBatis Generator Configuration 1.0//EN"
            "http://mybatis.org/dtd/mybatis-generator-config_1_0.dtd">
    
    <generatorConfiguration>
        
        
        
    
        
        
        <classPathEntry
                location="C:\Repository\mysql\mysql-connector-java\5.1.38\mysql-connector-java-5.1.38.jar"/>
    
        
        
        <context id="MyBatis" targetRuntime="MyBatis3">
            
            <property name="autoDelimitKeywords" value="false"/>
            
            <property name="javaFileEncoding" value="UTF-8"/>
            
            <property name="javaFormatter" value="org.mybatis.generator.api.dom.DefaultJavaFormatter"/>
            
            <property name="xmlFormatter" value="org.mybatis.generator.api.dom.DefaultXmlFormatter"/>
    
            
            <commentGenerator>
                <property name="suppressAllComments" value="true"/>
                <property name="suppressDate" value="true"/>
            </commentGenerator>
    
            
            <jdbcConnection driverClass="com.mysql.jdbc.Driver"
                            connectionURL="jdbc:mysql://localhost:3306/test"
                            userId="root"
                            password="root"/>
    
                    
            <javaTypeResolver>
                
                <property name="forceBigDecimals" value="false"/>
            </javaTypeResolver>
    
            
            <javaModelGenerator targetPackage="com.study.springboot.mybatis.model"
                                targetProject="E:\WorkSpace\study\springboot\mybatis\src\main\java">
    
                
                
    
                
                <property name="enableSubPackages" value="false"/>
    
                
                
    
                
                
    
                
                <property name="trimStrings" value="true"/>
            </javaModelGenerator>
    
            
            <sqlMapGenerator targetPackage="mapper"
                             targetProject="E:\WorkSpace\study\springboot\mybatis\src\main\resources">
                
                <property name="enableSubPackages" value="false"/>
            </sqlMapGenerator>
    
            
            <javaClientGenerator type="XMLMAPPER" targetPackage="com.study.springboot.mybatis.mapper"
                                 targetProject="E:\WorkSpace\study\springboot\mybatis\src\main\java">
                
                <property name="enableSubPackages" value="false"/>
    
                
            </javaClientGenerator>
    
            
            <table tableName="%"
                   enableCountByExample="false"
                   enableUpdateByExample="false"
                   enableDeleteByExample="false"
                   enableSelectByExample="false"
                   selectByExampleQueryId="false">
                
                
    
                
                
    
                
                
    
                
                
    
                
                
    
                
                
    
                
                
    
                
                
    
                
                
    
                
                
    
                
                
    
                
                
    
                
                
    
                
                
    
                
                
    
                
                
    
                
                
    
                
                
    
                
                
    
                
                
            </table>
        </context>
    </generatorConfiguration>

###### 2.4 生成xxxMapper.java接口以及xxxMapper.xml文件 ######

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3RpYW50YW5nXzE5ODY_size_16_color_FFFFFF_t_70 3]  
注意，如果存放xxxMapper.java和xxxMapper.xml文件的包不存在会报错

###### 2.5 修改自动生成的实体类 ######

对于model包下的实体类需要添加基于JPA的注解,否则JPA接口无法引用  
例如对于User.java实体类需要进行如下修改

package com.study.springboot.mybatis.model;
    
    import javax.persistence.*;
    
    @Entity
    @Table(name = "user")
    public class User {
        
    
        @Id
        @GeneratedValue
        @Column(name = "id")
        private Integer id;
    
        @Column(name = "user_name")
        private String userName;
    
        @Column(name = "passwd")
        private String passwd;
    
        @Column(name = "nick_name")
        private String nickName;
    
        @Column(name = "telephone")
        private String telephone;
    
        @Column(name = "email")
        private String email;
    
        @Column(name = "authority")
        private Integer authority;
    
        @Column(name = "department")
        private String department;
    
        @Column(name = "create_at")
        private String createAt;
    
        @Column(name = "update_at")
        private String updateAt;
    
        // 省略get&set
    }

###### 2.6 添加xxxJPA接口,例如UserJPA.java ######

import org.springframework.data.jpa.repository.JpaRepository;
    import org.springframework.data.jpa.repository.JpaSpecificationExecutor;
    
    import java.io.Serializable;
    
    public interface UserJPA extends
            Serializable,
            JpaRepository<User, Integer>,
            JpaSpecificationExecutor<User> {
        
    }

###### 2.7 测试 ######

测试之前需要配置application.yml(你的有能是application.properties,改一下后缀名即可,我比较喜欢.yml文件的简洁)

spring:
      datasource:
        type: com.alibaba.druid.pool.DruidDataSource
        url: jdbc:mysql://localhost:3306/test?useUnicode=true&characterEncoding=utf8&characterSetResults=utf8
        driver-class-name: com.mysql.jdbc.Driver
        username: root
        password: root
    mybatis:
      # 重要配置
      type-aliases-package: com.study.springboot.mybatis.model
      mapper-locations: classpath:mapper/*.xml

对于每一个xxxMapper.java接口，需要使用@Component注解  
自动生成的xxxMapper.java接口是不带@Component注解的

@Component
    public interface UserMapper {
        
        int deleteByPrimaryKey(Integer id);
    
        int insert(User record);
    
        int insertSelective(User record);
    
        User selectByPrimaryKey(Integer id);
    
        int updateByPrimaryKeySelective(User record);
    
        int updateByPrimaryKey(User record);
    }

在入口类中需要添加@MapperScan(“com.study.springboot.mybatis.mapper”)注解

@SpringBootApplication
    @MapperScan("com.study.springboot.mybatis.mapper")
    public class MybatisApplication {
        
    
        public static void main(String[] args) {
        
            SpringApplication.run(MybatisApplication.class, args);
        }
    }

打开测试类，为测试类添加@MapperScan(“com.study.springboot.mybatis.mapper”)注解

@RunWith(SpringRunner.class)
    @SpringBootTest
    @MapperScan("com.study.springboot.mybatis.mapper")
    public class MybatisApplicationTests {
        
    
        @Autowired
        private UserMapper userMapper;
        
        @Autowired
        private UserJPA userJPA;
    
        @Test
        public void contextLoads() {
        
            System.out.println(userMapper.selectByPrimaryKey(11).getUserName());//mybatis方式
            System.out.println(userJPA.findOne(11).getUserName());//JPA方式
        }
    }

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3RpYW50YW5nXzE5ODY_size_16_color_FFFFFF_t_70 4]  
如果出现

java.lang.NoClassDefFoundError: org/apache/ibatis/session/SqlSession

的错误，请检查本地Maven仓库的配置，有可能是没有Maven没有下载需要引用的包

--------------------

原文：[https://www.cnblogs.com/yueguanguanyun/p/9258288.html][https_www.cnblogs.com_yueguanguanyun_p_9258288.html]

[Link 1]: http://www.mybatis.org/generator/index.html
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3RpYW50YW5nXzE5ODY_size_16_color_FFFFFF_t_70]: https://img-blog.csdnimg.cn/20190610143122301.?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3RpYW50YW5nXzE5ODY=,size_16,color_FFFFFF,t_70
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[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3RpYW50YW5nXzE5ODY_size_16_color_FFFFFF_t_70 2]: https://img-blog.csdnimg.cn/20190610143146499.?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3RpYW50YW5nXzE5ODY=,size_16,color_FFFFFF,t_70
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3RpYW50YW5nXzE5ODY_size_16_color_FFFFFF_t_70 3]: https://img-blog.csdnimg.cn/20190610143258160.?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3RpYW50YW5nXzE5ODY=,size_16,color_FFFFFF,t_70
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3RpYW50YW5nXzE5ODY_size_16_color_FFFFFF_t_70 4]: https://img-blog.csdnimg.cn/20190610143508535.?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3RpYW50YW5nXzE5ODY=,size_16,color_FFFFFF,t_70
[https_www.cnblogs.com_yueguanguanyun_p_9258288.html]: https://www.cnblogs.com/yueguanguanyun/p/9258288.html