springboot中mybatisplus配置信息

以下是SpringBoot整合MyBatisPlus配置信息的步骤：

1.在pom.xml文件中添加MyBatisPlus和MySQL驱动的依赖：

<dependency>
    <groupId>com.baomidou</groupId>
    <artifactId>mybatis-plus-boot-starter</artifactId>
    <version>3.4.2</version>
</dependency>
<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
</dependency>

2.在application.yml文件中配置数据源信息和MyBatisPlus的相关配置：

spring:
  datasource:
    dynamic:
      primary: master
      datasource:
        master:
          driver-class-name: com.mysql.cj.jdbc.Driver
          url: jdbc:mysql://localhost:3306/db_master?useUnicode=true&characterEncoding=utf-8&serverTimezone=Asia/Shanghai
          username: root
          password: root
        slave:
          driver-class-name: com.mysql.cj.jdbc.Driver
          url: jdbc:mysql://localhost:3306/db_slave?useUnicode=true&characterEncoding=utf-8&serverTimezone=Asia/Shanghai
          username: root
          password: root
  mybatis-plus:
    mapper-locations: classpath*:mapper/**/*.xml
    type-aliases-package: com.example.demo.entity

3.创建数据源配置类DynamicDataSourceConfig，用于动态切换数据源：

@Configuration
public class DynamicDataSourceConfig {

    @Bean
    @ConfigurationProperties("spring.datasource.druid.master")
    public DataSource masterDataSource() {
        return DruidDataSourceBuilder.create().build();
    }

    @Bean
    @ConfigurationProperties("spring.datasource.druid.slave")
    public DataSource slaveDataSource() {
        return DruidDataSourceBuilder.create().build();
    }

    @Bean
    @Primary
    public DynamicDataSource dataSource(DataSource masterDataSource, DataSource slaveDataSource) {
        Map<Object, Object> targetDataSources = new HashMap<>();
        targetDataSources.put(DataSourceEnum.MASTER.getName(), masterDataSource);
        targetDataSources.put(DataSourceEnum.SLAVE.getName(), slaveDataSource);
        return new DynamicDataSource(masterDataSource, targetDataSources);
    }
}

4.创建数据源枚举类DataSourceEnum，用于定义数据源的名称：

public enum DataSourceEnum {

    MASTER("master"),
    SLAVE("slave");

    private String name;

    DataSourceEnum(String name) {
        this.name = name;
    }

    public String getName() {
        return name;
    }
}

5.创建动态数据源类DynamicDataSource，用于动态切换数据源：

public class DynamicDataSource extends AbstractRoutingDataSource {

    private static final ThreadLocal<String> CONTEXT_HOLDER = new ThreadLocal<>();

    private final Map<Object, Object> targetDataSources;

    public DynamicDataSource(DataSource defaultDataSource, Map<Object, Object> targetDataSources) {
        super.setDefaultTargetDataSource(defaultDataSource);
        this.targetDataSources = targetDataSources;
        super.setTargetDataSources(this.targetDataSources);
        super.afterPropertiesSet();
    }

    @Override
    protected Object determineCurrentLookupKey() {
        return getDataSource();
    }

    public static void setDataSource(String dataSource) {
        CONTEXT_HOLDER.set(dataSource);
    }

    public static String getDataSource() {
        return CONTEXT_HOLDER.get();
    }

    public static void clearDataSource() {
        CONTEXT_HOLDER.remove();
    }

    @Override
    public void afterPropertiesSet() {
        super.afterPropertiesSet();
    }
}

6.创建数据源切换的AOP类DataSourceAspect，用于在方法执行前切换数据源：

@Aspect
@Component
public class DataSourceAspect {

    @Pointcut("@annotation(com.example.demo.annotation.DataSource)")
    public void dataSourcePointCut() {
    }

    @Before("dataSourcePointCut()")
    public void before(JoinPoint joinPoint) {
        MethodSignature signature = (MethodSignature) joinPoint.getSignature();
        DataSource dataSource = signature.getMethod().getAnnotation(DataSource.class);
        if (dataSource == null) {
            DynamicDataSource.setDataSource(DataSourceEnum.MASTER.getName());
        } else {
            DynamicDataSource.setDataSource(dataSource.value().getName());
        }
    }

    @After("dataSourcePointCut()")
    public void after(JoinPoint joinPoint) {
        DynamicDataSource.clearDataSource();
    }
}

7.在Mapper接口中使用@Mapper注解，并在Mapper.xml文件中使用MyBatisPlus提供的标签进行SQL语句的编写。