<dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
        </dependency>
        <dependency>
            <groupId>cn.hutool</groupId>
            <artifactId>hutool-all</artifactId>
        </dependency>
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid-spring-boot-starter</artifactId>
        </dependency>
        <!--mybatis plus-->
        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-boot-starter</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-aop</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-jdbc</artifactId>
        </dependency>
    </dependencies>

server:
  port: 8007


spring:
  application:
    name:  dynamic-source
  jackson:
    date-format: yyyy-MM-dd HH:mm:ss
    time-zone: GMT+8
  datasource:
    type: com.alibaba.druid.pool.DruidDataSource
    driverClassName: com.mysql.cj.jdbc.Driver
    ds:
      # 主庫(kù)數(shù)據(jù)源
      master:
        url: jdbc:mysql://localhost:3307/test01?useUnicode=true&characterEncoding=utf8&zeroDateTimeBehavior=convertToNull&useSSL=true&serverTimezone=GMT%2B8
        username: root
        password: root
      # 從庫(kù)數(shù)據(jù)源
      slave:
        url: jdbc:mysql://localhost:3307/test02?useUnicode=true&characterEncoding=utf8&zeroDateTimeBehavior=convertToNull&useSSL=true&serverTimezone=GMT%2B8
        username: root
        password: root
    # 初始連接數(shù)
    initialSize: 5
    # 最小連接池?cái)?shù)量
    minIdle: 10
    # 最大連接池?cái)?shù)量
    maxActive: 20
    # 配置獲取連接等待超時(shí)的時(shí)間
    maxWait: 60000
    # 配置間隔多久才進(jìn)行一次檢測(cè)，檢測(cè)需要關(guān)閉的空閑連接，單位是毫秒
    timeBetweenEvictionRunsMillis: 60000
    # 配置一個(gè)連接在池中最小生存的時(shí)間，單位是毫秒
    minEvictableIdleTimeMillis: 300000
    # 配置一個(gè)連接在池中最大生存的時(shí)間，單位是毫秒
    maxEvictableIdleTimeMillis: 900000
    # 配置檢測(cè)連接是否有效
    validationQuery: SELECT 1 FROM DUAL
    testWhileIdle: true
    testOnBorrow: false
    testOnReturn: false
    webStatFilter:
      enabled: true
    statViewServlet:
      enabled: true
      # 設(shè)置白名單，不填則允許所有訪問(wèn)
      allow:
      url-pattern: /druid/*
      # 控制臺(tái)管理用戶名和密碼
      login-username: admin
      login-password: 123456
    filter:
      stat:
        enabled: true
        # 慢SQL記錄
        log-slow-sql: true
        slow-sql-millis: 1000
        merge-sql: true
      wall:
        config:
          multi-statement-allow: true


logging:
  level:
    org.javatop: debug
  pattern:
    dateformat: HH:mm:ss:SSS
  file:
    path: "logs/${spring.application.name}"

CREATE TABLE `user` (
  `id` int NOT NULL AUTO_INCREMENT,
  `username` varchar(50) DEFAULT NULL,
  `age` int DEFAULT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=101 DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci;

package org.javatop.dynamic.config;

import com.alibaba.druid.pool.DruidDataSource;
import org.springframework.boot.context.properties.ConfigurationProperties;

import javax.sql.DataSource;
import java.util.Map;

/**
 * @author : Leo
 * @version 1.0
 * @date 2024-01-02 15:10
 * @description :
 */
@ConfigurationProperties(prefix = "spring.datasource")
public class DruidProperties {
    private String type;
    private String driverClassName;
    private Map<String, Map<String,String>> ds;

    private Integer initialSize;
    private Integer minIdle;
    private Integer maxActive;
    private Integer maxWait;

    /**
     *一會(huì)在外部構(gòu)建好一個(gè) DruidDataSource 對(duì)象，包含三個(gè)核心屬性 url、username、password
     * 在這個(gè)方法中設(shè)置公共屬性
     * @param druidDataSource
     * @return
     */
    public DataSource dataSource(DruidDataSource druidDataSource){
        druidDataSource.setInitialSize(initialSize);
        druidDataSource.setMinIdle(minIdle);
        druidDataSource.setMaxActive(maxActive);
        druidDataSource.setMaxWait(maxWait);
        return druidDataSource;
    }
    public String getType() {
        return type;
    }

    public void setType(String type) {
        this.type = type;
    }

    public String getDriverClassName() {
        return driverClassName;
    }

    public void setDriverClassName(String driverClassName) {
        this.driverClassName = driverClassName;
    }

    public Map<String, Map<String, String>> getDs() {
        return ds;
    }

    public void setDs(Map<String, Map<String, String>> ds) {
        this.ds = ds;
    }

    public Integer getInitialSize() {
        return initialSize;
    }

    public void setInitialSize(Integer initialSize) {
        this.initialSize = initialSize;
    }

    public Integer getMinIdle() {
        return minIdle;
    }

    public void setMinIdle(Integer minIdle) {
        this.minIdle = minIdle;
    }

    public Integer getMaxActive() {
        return maxActive;
    }

    public void setMaxActive(Integer maxActive) {
        this.maxActive = maxActive;
    }

    public Integer getMaxWait() {
        return maxWait;
    }

    public void setMaxWait(Integer maxWait) {
        this.maxWait = maxWait;
    }
}

package org.javatop.dynamic.config;

import com.alibaba.druid.pool.DruidDataSource;
import com.alibaba.druid.pool.DruidDataSourceFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.context.properties.EnableConfigurationProperties;
import org.springframework.stereotype.Component;

import javax.sql.DataSource;
import java.util.HashMap;
import java.util.Map;
import java.util.Set;

/**
 * @author : Leo
 * @version 1.0
 * @date 2024-01-02 15:12
 * @description : 加載數(shù)據(jù)源
 */

@Component
@EnableConfigurationProperties(DruidProperties.class)
public class LoadDataSource {

    @Autowired
    DruidProperties druidProperties;

    public Map<String, DataSource> loadAllDataSource()   {
        Map<String, DataSource> map =new HashMap<>();
        Map<String, Map<String, String>> ds = druidProperties.getDs();
        try {
            Set<String> keySet = ds.keySet();
            for (String key : keySet) {
                map.put(key, druidProperties.dataSource((DruidDataSource) DruidDataSourceFactory.createDataSource(ds.get(key))));
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        return map;
    }
}

package org.javatop.dynamic.utils;

/**
 * @author : Leo
 * @version 1.0
 * @date 2024-01-02 15:13
 * @description : ThreadLocal工具類
 */
public class DynamicDataSourceUtil {

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

    public static void setDataSourceType(String dsType){
        CONTEXT_HOLDER.set(dsType);
    }
    public static String getDataSourceType(){
        return CONTEXT_HOLDER.get();
    }

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

package org.javatop.dynamic.constant;

/**
 * @author : Leo
 * @version 1.0
 * @date 2024-01-02 15:13
 * @description :
 */
public interface DataSourceType {
    String default_ds_name ="master";
}

package org.javatop.dynamic.annotation;

import org.javatop.dynamic.constant.DataSourceType;

import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

/**
 * @author : Leo
 * @version 1.0
 * @date 2024-01-02 15:14
 * @description :  這個(gè)注解將來(lái)可以加在某一個(gè) service 類上或者方法上，通過(guò) value 屬性來(lái)指定類或者方法應(yīng)該使用哪個(gè)數(shù)據(jù)源
 */
@Retention(RetentionPolicy.RUNTIME)
@Target({ElementType.TYPE, ElementType.METHOD})
public @interface DataSource{

    /**
     * 如果一個(gè)方法上加了 @DataSource 注解，但是卻沒(méi)有指定數(shù)據(jù)源的名稱，那么默認(rèn)使用 Master 數(shù)據(jù)源
     * @return
     */
    String value() default DataSourceType.default_ds_name;
}

package org.javatop.dynamic.annotation;

import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.annotation.Around;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Pointcut;
import org.aspectj.lang.reflect.MethodSignature;
import org.javatop.dynamic.utils.DynamicDataSourceUtil;
import org.springframework.core.annotation.AnnotationUtils;
import org.springframework.stereotype.Component;

/**
 * @author : Leo
 * @version 1.0
 * @date 2024-01-02 15:15
 * @description : AOP解析自定義注解
 */
@Component
@Aspect
public class DataSourceAspect {


    /**
     * @annotation(org.javatop.dynamic.annotation.DataSource) 表示方法上有 @DataSource 注解 就將方法攔截下來(lái)。
     * @within :如果類上面有 @DataSource 注解，就將類中的方法攔截下來(lái)。
     */
    @Pointcut("@annotation(org.javatop.dynamic.annotation.DataSource) || " +
            "@within(org.javatop.dynamic.annotation.DataSource)")
    public void pc(){

    }

    @Around("pc()")
    public Object around(ProceedingJoinPoint point){
        //獲取方法上面的注解
        DataSource dataSource =getDataSource(point);
        if(dataSource!=null){
            // 注解中數(shù)據(jù)源的名稱
            String value = dataSource.value();
            DynamicDataSourceUtil.setDataSourceType(value);
        }
        try {
            return point.proceed();
        } catch (Throwable throwable) {
            throwable.printStackTrace();
        }finally {
            DynamicDataSourceUtil.clear();
        }
        return null;
    }

    private DataSource getDataSource(ProceedingJoinPoint point) {
        /**
         * 先去查找方法上的注解，如果沒(méi)有，再去類中找。
         */
        MethodSignature signature = (MethodSignature)point.getSignature();
        DataSource annotation = AnnotationUtils.findAnnotation(signature.getMethod(), DataSource.class);
        if(annotation!=null){
            return annotation;
        }
        return AnnotationUtils.findAnnotation(signature.getDeclaringType(),DataSource.class);
    }
}

@Pointcut("@annotation(org.javatop.dynamic.annotation.DataSource) || " +
          "@within(org.javatop.dynamic.annotation.DataSource)")
public void pc() {

}

e@Around("pc()")
public Object around(ProceedingJoinPoint point) {
    DataSource dataSource = getDataSource(point);
    if (dataSource != null) {
        String value = dataSource.value();
        DynamicDataSourceUtil.setDataSourceType(value);
    }
    try {
        return point.proceed();
    } catch (Throwable throwable) {
        throwable.printStackTrace();
    } finally {
        DynamicDataSourceUtil.clear();
    }
    return null;
}

package org.javatop.dynamic.config;

import org.javatop.dynamic.constant.DataSourceType;
import org.javatop.dynamic.utils.DynamicDataSourceUtil;
import org.springframework.jdbc.datasource.lookup.AbstractRoutingDataSource;
import org.springframework.stereotype.Component;

import javax.sql.DataSource;
import java.util.HashMap;
import java.util.Map;

/**
 * @author : Leo
 * @version 1.0
 * @date 2024-01-02 15:18
 * @description : 定義動(dòng)態(tài)數(shù)據(jù)源
 */
@Component
public class DynamicDataSource extends AbstractRoutingDataSource {

    public DynamicDataSource(LoadDataSource loadDataSource) {
        // 1、設(shè)置所有的數(shù)據(jù)源
        Map<String, DataSource> stringDataSourceMap = loadDataSource.loadAllDataSource();
        super.setTargetDataSources(new HashMap<>(stringDataSourceMap));
        // 2、設(shè)置默認(rèn)的數(shù)據(jù)源
        super.setDefaultTargetDataSource(stringDataSourceMap.get(DataSourceType.default_ds_name));

        super.afterPropertiesSet();
    }

    /**
     * 這個(gè)方法用來(lái)返回?cái)?shù)據(jù)源名稱，當(dāng)系統(tǒng)需要獲取數(shù)據(jù)源的時(shí)候，會(huì)自動(dòng)調(diào)用該方法獲取數(shù)據(jù)源的名稱
     * @return
     */
    @Override
    protected Object determineCurrentLookupKey() {
        return DynamicDataSourceUtil.getDataSourceType();
    }
}

package org.javatop.dynamic.service;

import org.javatop.dynamic.annotation.DataSource;
import org.javatop.dynamic.domain.User;
import org.javatop.dynamic.mapper.UserMapper;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.List;

/**
 * @author : Leo
 * @version 1.0
 * @date 2024-01-02 15:26
 * @description :
 */
@Service
public class UserService{
    @Autowired
    private UserMapper userMapper;

    @DataSource("slave")
//    @DataSource
    public List<User> getAll(){
        List<User> all = userMapper.getAll();
        return all;
    }
}

package org.javatop.dynamic.mapper;

import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.annotations.Select;
import org.javatop.dynamic.domain.User;

import java.util.List;

/**
 * @author : Leo
 * @version 1.0
 * @date 2024-01-02 15:26
 * @description :
 */
@Mapper
public interface UserMapper {
    @Select("select * from user")
    List<User> getAll();
}

package org.javatop.dynamic;

import org.javatop.dynamic.domain.User;
import org.javatop.dynamic.service.UserService;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;

import java.util.List;

/**
 * @author : Leo
 * @version 1.0
 * @date 2024-01-02 15:32
 * @description :
 */
@SpringBootTest
public class DynamicTest {

    @Autowired
    private UserService userService;

    /**
     *  用于測(cè)試:
     */
    @Test
    public void test() {
        List<User> all = userService.getAll();
        if(all !=null){
            for (User user : all) {
                System.out.println(user);
            }
        }
    }
}