这篇文章主要为大家展示了“Mybatis如何通过Mapper代理连接数据库”，内容简而易懂，条理清晰，希望能够帮助大家解决疑惑，下面让小编带领大家一起研究并学习一下“Mybatis如何通过Mapper代理连接数据库”这篇文章吧。
1.在数据库中创建表和相应字段，如下图我创建了三个字段分别为fromname,message,toname，类型为varchar
2.创建对应的pojo实体类，注意类型要和数据库创建类型一致，如varchar()对应的是java.lang.String
3.在resource路径下配置config.xml，配置Mybatis的运行环境3306/后面加上自己的数据库schema名字，数据库username和password输入自己的账号和密码,而在下方mapper则是用于注册我们待会要写的xml文件，路径用/ 写上xml的全名称。
<?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> <!--配置Mybatis运行环境--> <environments default="development"><!--default命名--> <environment id="development"><!--和上面的一致--> <transactionManager type="JDBC"></transactionManager><!--事务管理 交给JDBC--> <!-- 数据源 --> <dataSource type="POOLED"> <property name="driver" value="com.mysql.cj.jdbc.Driver"/> <property name="url" value="jdbc:mysql://localhost:3306/bjpower? useUnicode=true&characterEncoding=UTF-8"/> <property name="username" value="root"/> <property name="password" value="xxxx"/> </dataSource> </environment> </environments> <mappers> <!-- <mapper resource="com/yyj/repository/msgdataRepository.xml"></mapper>--> <mapper resource="com/yyj/repository/msgdatanewRepository.xml"></mapper> </mappers> </configuration>
4.自定义接口，在repository包下自定义接口，待会在xml中实现即可
5.在repository中建立对应的xml文件，如我取的名称为MsgdatanewReposiotory,名字可自定义，注意mapper注册和改名字一样即可，然后编写sql语句
statement 的 id 为接⼝中对应的⽅法名
<?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.yyj.repository.MsgdatanewRepository"><!--接口全类名-->
<insert id="save1" parameterType="com.yyj.pojo.MessageData">
<!--parameterType为传入的参数类型，是刚刚设置的pojo类-->
insert into msgdatanew(fromname,message,toname) values (#{fromName},#{message},#{toName})
</insert>
<!--resultType为返回值类型-->
<select id="findByName1" parameterType="java.lang.String"
resultType="com.yyj.pojo.MessageData">
select * from msgdatanew where toname = #{toName}
</select>
</mapper>6.调用测试类即可，注意要添加commit事务才能提交成功，数据库才有变化
package com.yyj.Test;
import com.yyj.pojo.MessageData;
import com.yyj.repository.MsgdatanewRepository;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
import java.io.InputStream;
public class Test2 {
// public void add(String toName,String message,String fromName){
public static void main(String[] args) {
InputStream inputStream = Test2.class.getClassLoader().getResourceAsStream("config.xml");
SqlSessionFactoryBuilder sqlSessionFactoryBuilder = new SqlSessionFactoryBuilder();
SqlSessionFactory sqlSessionFactory = sqlSessionFactoryBuilder.build(inputStream);
SqlSession sqlSession = sqlSessionFactory.openSession();
MsgdatanewRepository msgdatanewRepository = sqlSession.getMapper(MsgdatanewRepository.class);
MessageData messageData=new MessageData();
messageData.setMessage("nihaoyayay");
messageData.setFromName("lisi");
int save = msgdatanewRepository.save1(messageData);
System.out.println(save);
sqlSession.commit();
}
}7.效果展示
8.附上pom.xml文件
<?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>
<groupId>com.demo</groupId>
<artifactId>websocket-chatroom</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>websocket-chatroom</name>
<description>WebSocket示例工程</description>
<properties>
<java.version>1.8</java.version>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
<spring-boot.version>2.3.7.RELEASE</spring-boot.version>
</properties>
<dependencies>
<!--mybatis-->
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis</artifactId>
<version>3.4.5</version>
</dependency>
<!--mysql驱动-->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>8.0.27</version>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-websocket</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-devtools</artifactId>
<scope>runtime</scope>
<optional>true</optional>
</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>
<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-dependencies</artifactId>
<version>${spring-boot.version}</version>
<type>pom</type>
<scope>import</scope>
</dependency>
<!-- <!– ehcache –>-->
<!-- <dependency>-->
<!-- <groupId>net.sf.ehcache</groupId>-->
<!-- <artifactId>ehcache-core</artifactId>-->
<!-- <version>2.4.3</version>-->
<!-- </dependency> <dependency>-->
<!-- <groupId>org.mybatis</groupId>-->
<!-- <artifactId>mybatis-ehcache</artifactId>-->
<!-- <version>1.0.0</version>-->
<!-- </dependency>-->
</dependencies>
</dependencyManagement>
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.8.1</version>
<configuration>
<source>1.8</source>
<target>1.8</target>
<encoding>UTF-8</encoding>
</configuration>
</plugin>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
<version>2.3.7.RELEASE</version>
<configuration>
<mainClass>com.yyj.WebsocketChatroomApplication</mainClass>
</configuration>
<executions>
<execution>
<id>repackage</id>
<goals>
<goal>repackage</goal>
</goals>
</execution>
</executions>
</plugin>
</plugins>
<resources>
<resource>
<directory>src/main/java</directory>
<includes>
<include>**/*.xml</include>
</includes>
</resource>
</resources>
</build>
</project>以上是“Mybatis如何通过Mapper代理连接数据库”这篇文章的所有内容，感谢各位的阅读！相信大家都有了一定的了解，希望分享的内容对大家有所帮助，如果还想学习更多知识，欢迎关注亿速云行业资讯频道！
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