SpringBoot整合Mybaitis-使用mapper注解

末蓝、 2022-05-12 09:52 216阅读 0赞

上一篇博文已经详细介绍了SpringBoot环境搭建过程，这一节介绍一下SpringBoot整合Mybatis。

# SpringBoot整合Mybatis #

**方式1：mapper使用注解**

项目结构

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1：准备数据库数据和配置数据源

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 <td style="vertical-align:top;width:414.8pt;"> #数据源必填项 spring.datasource.driver-class-name= com.mysql.jdbc.Driver spring.datasource.url = jdbc:mysql://localhost:3306/study?useUnicode=true&amp;characterEncoding=utf-8 spring.datasource.username = root spring.datasource.password = 123456 &nbsp; #选填 # Number of ms to wait before throwing an exception if no connection is available. spring.datasource.tomcat.max-wait=10000 # Maximum number of active connections that can be allocated from this pool at the same time. spring.datasource.tomcat.max-active=50 # Validate the connection before borrowing it from the pool. spring.datasource.tomcat.test-on-borrow=true </td> 
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2：加maven依赖

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 <td style="vertical-align:top;width:414.8pt;"> &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &lt;!-- Spring-Mybatis --&gt; &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &lt;dependency&gt; &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &lt;groupId&gt;org.mybatis.spring.boot&lt;/groupId&gt; &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &lt;artifactId&gt;mybatis-spring-boot-starter&lt;/artifactId&gt; &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &lt;version&gt;1.3.2&lt;/version&gt; &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &lt;/dependency&gt; &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &lt;!-- MySQL驱动 --&gt; &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &lt;dependency&gt; &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &lt;groupId&gt;mysql&lt;/groupId&gt; &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &lt;artifactId&gt;mysql-connector-java&lt;/artifactId&gt; &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &lt;/dependency&gt; </td> 
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3：编写实体类

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 <td style="vertical-align:top;width:414.8pt;"> public class User implements Serializable { &nbsp; &nbsp;&nbsp;&nbsp;&nbsp; private static final long serialVersionUID = 1L; &nbsp; &nbsp;&nbsp;&nbsp;&nbsp; private int id;// id &nbsp; &nbsp;&nbsp;&nbsp;&nbsp; private String name;// 姓名 &nbsp; &nbsp;&nbsp;&nbsp;&nbsp; private int age;// 年龄 &nbsp; &nbsp;&nbsp;&nbsp;&nbsp; public int getId() { &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; return id; &nbsp;&nbsp;&nbsp;&nbsp; } &nbsp; &nbsp;&nbsp;&nbsp;&nbsp; public void setId(int id) { &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; this.id = id; &nbsp;&nbsp;&nbsp;&nbsp; } &nbsp; &nbsp;&nbsp;&nbsp;&nbsp; public String getName() { &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; return name; &nbsp;&nbsp;&nbsp;&nbsp; } &nbsp; &nbsp;&nbsp;&nbsp;&nbsp; public void setName(String name) { &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; this.name = name; &nbsp;&nbsp;&nbsp;&nbsp; } &nbsp; &nbsp;&nbsp;&nbsp;&nbsp; public int getAge() { &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; return age; &nbsp;&nbsp;&nbsp;&nbsp; } &nbsp; &nbsp;&nbsp;&nbsp;&nbsp; public void setAge(int age) { &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; this.age = age; &nbsp;&nbsp;&nbsp;&nbsp; } &nbsp; &nbsp;&nbsp;&nbsp;&nbsp; @Override &nbsp;&nbsp;&nbsp;&nbsp; public String toString() { &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; return "User [id=" + id + ", name=" + name + ", age=" + age + "]"; &nbsp;&nbsp;&nbsp;&nbsp; } &nbsp; } </td> 
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4：编写mapper

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 <td style="vertical-align:top;width:414.8pt;"> import java.util.List; &nbsp; import org.apache.ibatis.annotations.Mapper; import org.apache.ibatis.annotations.Select; &nbsp; import com.liujia.springdemo.entity.User; &nbsp; //@Mapper 这里可以使用@Mapper注解，但是每个mapper都加注解比较麻烦，所以统一配置@MapperScan在扫描路径在application类中 public interface UserMapper { &nbsp; &nbsp;&nbsp;&nbsp; /** &nbsp;&nbsp;&nbsp; &nbsp;* 获取所有的user对象 &nbsp;&nbsp;&nbsp; &nbsp;* &nbsp;&nbsp;&nbsp; &nbsp;* @return &nbsp;&nbsp;&nbsp; &nbsp;*/ &nbsp;&nbsp;&nbsp; @Select("SELECT *FROM user") &nbsp;&nbsp;&nbsp; List&lt;User&gt; getAll(); } </td> 
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5：编写service层

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 <td style="vertical-align:top;width:414.8pt;"> import java.util.List; &nbsp; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Service; &nbsp; import com.liujia.springdemo.entity.User; import com.liujia.springdemo.mapper.UserMapper; &nbsp; @Service public class UserService { &nbsp;&nbsp;&nbsp; @Autowired &nbsp;&nbsp;&nbsp; private UserMapper userMapper; &nbsp; &nbsp;&nbsp;&nbsp; public List&lt;User&gt; getAll() { &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; return userMapper.getAll(); &nbsp;&nbsp;&nbsp; }; } </td> 
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6：编写Copntroller层

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 <td style="vertical-align:top;width:414.8pt;"> import java.util.List; &nbsp; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RestController; &nbsp; import com.liujia.springdemo.entity.User; import com.liujia.springdemo.service.UserService; &nbsp; @RestController public class UserController { &nbsp; &nbsp;&nbsp;&nbsp;&nbsp; @Autowired &nbsp;&nbsp;&nbsp;&nbsp; private UserService userService; &nbsp; &nbsp;&nbsp;&nbsp;&nbsp; @RequestMapping("/getallusers") &nbsp;&nbsp;&nbsp;&nbsp; public List&lt;User&gt; getAllUsers() { &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; return userService.getAll();&nbsp;&nbsp;&nbsp;&nbsp; &nbsp;&nbsp;&nbsp;&nbsp; } } </td> 
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7：增加包扫描和运行程序

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 <td style="vertical-align:top;width:414.8pt;"> @SpringBootApplication @MapperScan(basePackages = { "com.liujia.springdemo.mapper"}) public class Application { &nbsp; &nbsp;&nbsp;&nbsp; public static void main(String[] args) { &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; SpringApplication.run(Application.class, args); &nbsp;&nbsp;&nbsp; } &nbsp; &nbsp;&nbsp;&nbsp; @Bean &nbsp;&nbsp;&nbsp; public CommandLineRunner commandLineRunner(ApplicationContext ctx) { &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; return args -&gt; { &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; System.out.println("Let's inspect the beans provided by Spring Boot:"); &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; String[] beanNames = ctx.getBeanDefinitionNames(); &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Arrays.sort(beanNames); &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; for (String beanName : beanNames) { &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; System.out.println(beanName); &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; } &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; }; &nbsp;&nbsp;&nbsp; } } </td> 
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运行结果

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参考文献

[https://docs.spring.io/spring-boot/docs/2.0.5.RELEASE/reference/htmlsingle/\#boot-features-using-jdbc-template][https_docs.spring.io_spring-boot_docs_2.0.5.RELEASE_reference_htmlsingle_boot-features-using-jdbc-template]

遇到问题

SLF4J: Failed to load class “org.slf4j.impl.StaticLoggerBinder”

解决办法

参见[https://blog.csdn.net/liuxiangke0210/article/details/77892564][https_blog.csdn.net_liuxiangke0210_article_details_77892564]

缺少jar包依赖

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 <td style="vertical-align:top;width:414.8pt;"> &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &lt;dependency&gt; &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &lt;groupId&gt;org.slf4j&lt;/groupId&gt; &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &lt;artifactId&gt;slf4j-simple&lt;/artifactId&gt; &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &lt;/dependency&gt; </td> 
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源码下载地址为：

[https://download.csdn.net/download/caoshangfeidie000/10670695][https_download.csdn.net_download_caoshangfeidie000_10670695]

[70]: /images/20220512/3f113de66f0c49d78a078e6a4401769f.png
[70 1]: /images/20220512/a50165b20a8648a3bdaadba152cf31ed.png
[70 2]: /images/20220512/b7fe4461da9647a2b93a1a29e25689d6.png
[https_docs.spring.io_spring-boot_docs_2.0.5.RELEASE_reference_htmlsingle_boot-features-using-jdbc-template]: https://docs.spring.io/spring-boot/docs/2.0.5.RELEASE/reference/htmlsingle/#boot-features-using-jdbc-template
[https_blog.csdn.net_liuxiangke0210_article_details_77892564]: https://blog.csdn.net/liuxiangke0210/article/details/77892564
[https_download.csdn.net_download_caoshangfeidie000_10670695]: https://download.csdn.net/download/caoshangfeidie000/10670695