dynamic-datasource多数据源快速体验

多数据源依赖dynamic-datasource框架

https://www.kancloud.cn/tracy5546/dynamic-datasource/2264611

环境搭建

1 mvn依赖

<?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.itmark</groupId>
    <artifactId>maynDs</artifactId>
    <version>0.0.1-SNAPSHOT</version>

    <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>
        <!--1.多数据源起步依赖-->
        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>dynamic-datasource-spring-boot-starter</artifactId>
            <version>3.5.0</version>
        </dependency>
        <!--2.springboot起步依赖-->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid-spring-boot-starter</artifactId>
            <version>1.2.6</version>
        </dependency>
        <!--3.springboot对web的支持-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <!--4.mybatis起步依赖-->
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>2.1.4</version>
        </dependency>
        <!--5.mysql驱动-->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <scope>runtime</scope>
        </dependency>
        <!--6.测试模块-->
        <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>
        </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.itmark.maynds.MaynDsApplication</mainClass>
                </configuration>
                <executions>
                    <execution>
                        <id>repackage</id>
                        <goals>
                            <goal>repackage</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>

</project>

2 配置文件

整俩数据库，里面建个表，里面自己整点数据

CREATE TABLE USER(
username VARCHAR(2000)
);

spring:
  datasource:
    dynamic:
      #设置默认的数据源或者数据源组,默认值即为master
      primary: mark1
      #严格匹配数据源,默认false. true未匹配到指定数据源时抛异常,false使用默认数据源
      strict: false
      datasource:
        # 3.2.0开始支持SPI可省略此配置
        mark1:
          url: jdbc:mysql://localhost:3306/blog?serverTimezone=UTC
          username: root
          password: root
          driver-class-name: com.mysql.cj.jdbc.Driver
        mark2:
          url: jdbc:mysql://localhost:3306/liaoning?serverTimezone=UTC
          username: root
          password: root
          driver-class-name: com.mysql.cj.jdbc.Driver
mybatis:
  mapper-locations: classpath:mappers/*xml

3 排除数据源自动配置

这里mapper扫描包也配置上去了

@SpringBootApplication(exclude={DataSourceAutoConfiguration.class})
@MapperScan("com.itmark.maynds.mapper")
public class MaynDsApplication {

    public static void main(String[] args) {
        SpringApplication.run(MaynDsApplication.class, args);
    }

}

4 常规代码

a mapper和xml

@Mapper
public interface UserMapper {
    List<User> getUsers();
}

<?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.itmark.maynds.mapper.UserMapper">
    <select id="getUsers" resultType="com.itmark.maynds.entity.User">
        SELECT username FROM USER;
    </select>
 </mapper>

b 实体和service

public class User implements Serializable {
    private String username;

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public User() {
    }

    public User(String username) {
        this.username = username;
    }

    @Override
    public String toString() {
        return "User{" +
                "username='" + username + '\'' +
                '}';
    }
}

service接口

public interface UserService {
    List<User> getUsers();
}

service

@Service
public class UserServiceImpl implements UserService{
    @Autowired
    private UserMapper userMapper;
    @Override
    public List<User> getUsers() {
        return userMapper.getUsers();
    }
}

5 controller

**@DS(“mark1”)**该注解可以加在和数据库操作相关的类上或者方法上，没有必要全部加在controller上

@RestController
@RequestMapping("/api")
public class UserController {
    @Autowired
    private UserService userService;

    @GetMapping("/user1")
    @DS("mark1")
    public List<User> getUsers() {
        return userService.getUsers();
    }

    @GetMapping("/user2")
    @DS("mark2")
    public List<User> getUsers2() {
        return userService.getUsers();
    }
}

6测试