SpringBoot第三篇SpringBoo和Mybatis整合

1、新建springboot项目，选择mysql、jdbc、web，使用maven管理项目

 

 

2、检查pom.xml依赖，已经添加了mybatis、spring-boot、junit依赖

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<?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>2.5.6</version>         <relativePath/> <!-- lookup parent from repository -->     </parent>     <groupId>cn.yinmingneng</groupId>     <artifactId>springboot1028001</artifactId>     <version>0.0.1-SNAPSHOT</version>     <name>springboot1028001</name>     <description>springboot1028001</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>2.2.0</version>         </dependency>           <dependency>             <groupId>mysql</groupId>             <artifactId>mysql-connector-java</artifactId>             <scope>runtime</scope>         </dependency>         <dependency>             <groupId>org.springframework.boot</groupId>             <artifactId>spring-boot-starter-test</artifactId>             <scope>test</scope>         </dependency>     </dependencies>       <build>         <plugins>             <plugin>                 <groupId>org.springframework.boot</groupId>                 <artifactId>spring-boot-maven-plugin</artifactId>             </plugin>         </plugins>     </build>   </project>

　　

 

3、编写映射实体，user

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public class user {     private Integer id;       public Integer getId() {         return id;     }       public void setId(Integer id) {         this.id = id;     }       public String getUser_id() {         return user_id;     }       public void setUser_id(String user_id) {         this.user_id = user_id;     }       public String getUser_name() {         return user_name;     }       public void setUser_name(String user_name) {         this.user_name = user_name;     }       public String getPassword() {         return password;     }       public void setPassword(String password) {         this.password = password;     }       public String getEmail() {         return email;     }       public void setEmail(String email) {         this.email = email;     }       private String user_id;     private  String user_name;     private String password;     private  String email; }

4、编写仓储接口，一定要写成接口，他自动生成实现类

@Repository
public interface UserMapper  {
    List<user> GetUserById();
}

 

5、编写xml文件，定义sql语句

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<?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="cn.yinmingneng.springboot1028001.Mapper.UserMapper">     <select id="GetUserById" resultType="cn.yinmingneng.springboot1028001.Entities.user">         select * from user     </select> </mapper>

xml文件放在resources文件夹下的mapping文件下下

 

 

 

6、应用程序启动配置，我使用了yml文件，读起来方便，一定要配置spring的daatasource否则会报错，mybatis的获取xml文件的路径，

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1	typeAliasesPackage:类的别名

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server:   port: 8095   Spring:   datasource:     username: root     password: root     url: jdbc:mysql://localhost:3306/5555?useUnicode=true&characterEncoding=utf-8&useSSL=true&serverTimezone=UTC     driver-class-name: com.mysql.jdbc.Driver   mybatis:   mapper-locations: classpath:Mapping/*.xml   //typeAliasesPackage:cn.yinmingneng.springboot1028001.Mapper

7、启动程序配置扫描包,如果不配置扫描包的路径会找不到这些接口

@MapperScan("cn.yinmingneng.springboot1028001.Mapper")

 Field userMapper in cn.yinmingneng.springboot1028001.Services.UserServices required a bean of type 'cn.yinmingneng.springboot1028001.Mapper.UserMapper' that could not be found.

8、测试、启动测试