Spring Boot 3.4.0 结合 Mybatis-plus 实现动态数据源的完整方案

<dependencies>
    <!-- spring boot starter -->
    <dependency>
        <groupid>org.springframework.boot</groupid>
        <artifactid>spring-boot-starter-web</artifactid>
    </dependency>
    <!-- mybatis-plus -->
    <dependency>
        <groupid>com.baomidou</groupid>
        <artifactid>mybatis-plus-boot-starter</artifactid>
        <version>3.5.3.1</version>
    </dependency>
    <!-- 数据库驱动 -->
    <dependency>
        <groupid>mysql</groupid>
        <artifactid>mysql-connector-java</artifactid>
        <scope>runtime</scope>
    </dependency>
    <!-- 其他工具 -->
    <dependency>
        <groupid>org.projectlombok</groupid>
        <artifactid>lombok</artifactid>
        <optional>true</optional>
    </dependency>
</dependencies>

spring:
  datasource:
    master:
      driver-class-name: com.mysql.cj.jdbc.driver
      url: jdbc:mysql://localhost:3306/master_db?usessl=false&servertimezone=utc
      username: root
      password: 123456
    slave1:
      driver-class-name: com.mysql.cj.jdbc.driver
      url: jdbc:mysql://localhost:3306/slave1_db?usessl=false&servertimezone=utc
      username: root
      password: 123456
    slave2:
      driver-class-name: com.mysql.cj.jdbc.driver
      url: jdbc:mysql://localhost:3306/slave2_db?usessl=false&servertimezone=utc
      username: root
      password: 123456

public enum datasourcetype {
    master("master"),
    slave1("slave1"),
    slave2("slave2");
    private final string name;
    datasourcetype(string name) {
        this.name = name;
    }
    public string getname() {
        return name;
    }
}

public class dynamicdatasourcecontextholder {
    private static final threadlocal<string> context_holder = new threadlocal<>();
    public static void setdatasourcetype(string datasourcetype) {
        context_holder.set(datasourcetype);
    }
    public static string getdatasourcetype() {
        return context_holder.get();
    }
    public static void cleardatasourcetype() {
        context_holder.remove();
    }
}

@configuration
@mapperscan(basepackages = "com.example.mapper")
public class dynamicdatasourceconfig {
    @bean
    @configurationproperties("spring.datasource.master")
    public datasource masterdatasource() {
        return datasourcebuilder.create().build();
    }
    @bean
    @configurationproperties("spring.datasource.slave1")
    public datasource slave1datasource() {
        return datasourcebuilder.create().build();
    }
    @bean
    @configurationproperties("spring.datasource.slave2")
    public datasource slave2datasource() {
        return datasourcebuilder.create().build();
    }
    @bean
    public datasource dynamicdatasource() {
        map<object, object> targetdatasources = new hashmap<>();
        targetdatasources.put(datasourcetype.master.getname(), masterdatasource());
        targetdatasources.put(datasourcetype.slave1.getname(), slave1datasource());
        targetdatasources.put(datasourcetype.slave2.getname(), slave2datasource());
        dynamicdatasource dynamicdatasource = new dynamicdatasource();
        dynamicdatasource.settargetdatasources(targetdatasources);
        dynamicdatasource.setdefaulttargetdatasource(masterdatasource());
        return dynamicdatasource;
    }
    @bean
    public platformtransactionmanager transactionmanager(datasource datasource) {
        return new datasourcetransactionmanager(datasource);
    }
}

public class dynamicdatasource extends abstractroutingdatasource {
    @override
    protected object determinecurrentlookupkey() {
        return dynamicdatasourcecontextholder.getdatasourcetype();
    }
}

@target({elementtype.method, elementtype.type})
@retention(retentionpolicy.runtime)
@documented
public @interface datasource {
    datasourcetype value() default datasourcetype.master;
}

@aspect
@component
@order(-1)
@slf4j
public class datasourceaspect {
    @pointcut("@annotation(com.example.annotation.datasource)" +
            "|| @within(com.example.annotation.datasource)")
    public void dspointcut() {
    }
    @around("dspointcut()")
    public object around(proceedingjoinpoint point) throws throwable {
        datasource datasource = getdatasource(point);
        if (datasource != null) {
            dynamicdatasourcecontextholder.setdatasourcetype(datasource.value().getname());
        }
        try {
            return point.proceed();
        } finally {
            dynamicdatasourcecontextholder.cleardatasourcetype();
        }
    }
    private datasource getdatasource(proceedingjoinpoint point) {
        methodsignature signature = (methodsignature) point.getsignature();
        datasource datasource = annotationutils.findannotation(signature.getmethod(), datasource.class);
        if (datasource != null) {
            return datasource;
        }
        return annotationutils.findannotation(signature.getdeclaringtype(), datasource.class);
    }
}

@service
public class userserviceimpl implements userservice {
    @autowired
    private usermapper usermapper;
    @override
    @datasource(datasourcetype.master)
    public user getmasteruser(long id) {
        return usermapper.selectbyid(id);
    }
    @override
    @datasource(datasourcetype.slave1)
    public user getslave1user(long id) {
        return usermapper.selectbyid(id);
    }
    @override
    @datasource(datasourcetype.slave2)
    public user getslave2user(long id) {
        return usermapper.selectbyid(id);
    }
}

@restcontroller
@requestmapping("/user")
public class usercontroller {
    @autowired
    private userservice userservice;
    @getmapping("/master/{id}")
    public user master(@pathvariable long id) {
        return userservice.getmasteruser(id);
    }
    @getmapping("/slave1/{id}")
    public user slave1(@pathvariable long id) {
        return userservice.getslave1user(id);
    }
    @getmapping("/slave2/{id}")
    public user slave2(@pathvariable long id) {
        return userservice.getslave2user(id);
    }
}