springboot整合druid及多数据源配置

前言

本篇主要分两部分 ①springboot整合druid的代码配置，以及druid的监控页面演示；②对实际场景中多数据源的配置使用进行讲解。

一、springboot整合druid的演示demo
可以用idea快速生成一个可运行的demo工程，具体可以参考如何快速创建springboot项目

主要用到的依赖如下:

<dependencies>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-data-jdbc</artifactId>
    </dependency>
    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <scope>runtime</scope>
    </dependency>
    <dependency>
        <groupId>com.alibaba</groupId>
        <artifactId>druid</artifactId>
        <version>1.2.17</version>
    </dependency>
   <dependency>
        <groupId>log4j</groupId>
        <artifactId>log4j</artifactId>
        <version>1.2.17</version>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-jdbc</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
</dependencies>

•  配置数据库需要的配置文件application.yml(注意格式和空格)

spring:
  datasource:
    username: root
    password: root
    url: jdbc:mysql://localhost:3306/firsttest?serverTimezone=UTC&useUnicode=true@characterEncoding=utf-8
    driver-class-name: com.mysql.jdbc.Driver
    type: com.alibaba.druid.pool.DruidDataSource
    poolPreparedStatements: true
     #配置监控统计拦截的filters，stat:监控统计、log4j：日志记录、wall：防御sql注入
     #如果允许时报错  java.lang.ClassNotFoundException: org.apache.log4j.Priority
 #则导入 log4j 依赖即可，Maven 地址： https://mvnrepository.com/artifact/log4j/log4j     filters: stat,wall,log4j
    maxPoolPreparedStatementPerConnectionSize: 20
    useGlobalDataSourceStat: true
    connectionProperties: druid.stat.mergeSql=true;druid.stat.slowSqlMillis=500

• 编写durid的启动配置类，加载数据库信息，和druid监控页面的初始化工作 

package com.czing.jdbcdemo.config;
 
import com.alibaba.druid.pool.DruidDataSource;
import com.alibaba.druid.support.http.StatViewServlet;
import com.alibaba.druid.support.http.WebStatFilter;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.boot.web.servlet.FilterRegistrationBean;
import org.springframework.boot.web.servlet.ServletRegistrationBean;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
 
import javax.servlet.Servlet;
import javax.sql.DataSource;
import java.util.Arrays;
import java.util.HashMap;
import java.util.Map;
 
 
@Configuration
public class DruidConfig {
        @ConfigurationProperties(prefix = "spring.datasource")
        @Bean
        public DataSource druidDataSource(){
            return new DruidDataSource();
        }
    /**
     * @Author wangchengzhi
     * @Description
     * 向DruidConfig中添加代码，配置druid监控管理台的servlet
     * @Date 22:12 2023/5/10
     * @Param
     * @return
     **/
    @Bean
    public ServletRegistrationBean druidServletRegistrationBean(){
        ServletRegistrationBean<Servlet> servletRegistrationBean = new ServletRegistrationBean<>(new StatViewServlet(),"/druid/*");
        Map<String,String> initParams = new HashMap<>();
        initParams.put("loginUsername","root");
        initParams.put("loginPassword","root");
        //后台允许谁可以访问
        //initParams.put("allow", "localhost")：表示只有本机可以访问
        //initParams.put("allow", "")：为空或者为null时，表示允许所有访问
        initParams.put("allow","");
        //deny：Druid 后台拒绝谁访问
        //initParams.put("msb", "192.168.1.20");表示禁止此ip访问
 
        servletRegistrationBean.setInitParameters(initParams);
        return servletRegistrationBean;
    }
 
    @Bean
    public FilterRegistrationBean webStatFilter() {
        FilterRegistrationBean bean = new FilterRegistrationBean();
        bean.setFilter(new WebStatFilter());
 
        //exclusions：设置哪些请求进行过滤排除掉，从而不进行统计
        Map<String, String> initParams = new HashMap<>();
        initParams.put("exclusions", "*.js,*.css,/druid/*");
        bean.setInitParameters(initParams);
 
        //"/*" 表示过滤所有请求
        bean.setUrlPatterns(Arrays.asList("/*"));
        return bean;
    }
}

•  编写controller类进行测试(此处使用jdbcTemplate进行演示)

package com.czing.jdbcdemo.controller;
 
import com.czing.jdbcdemo.mult.DataSource;
import com.czing.jdbcdemo.mult.DataSourceType;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
 
import java.util.List;
import java.util.Map;
 

@RestController
public class JDBCController {
    @Autowired
    JdbcTemplate jdbcTemplate;
 
    /**
     * @Author wangchengzhi
     * @Description
     * 使用springboot自带的jdbcTemplate实现数据库操作
     * @Date 21:34 2023/5/10
     * @Param
     * @return
     **/
    @RequestMapping("/selectTest")
    public List<Map<String, Object>> getTestAccount(){
        String sql ="select * from account";
        List<Map<String, Object>> maps = jdbcTemplate.queryForList(sql);
        return maps;
    }
}

•  启动项目，演示效果

项目启动日志: 

 druid的监控页面访问 http://localhost:8080/druid/sql.html

二、druid多数据源的配置使用

• 修改application.yml文件 

spring:
  datasource:
    local:
      username: root
      password: root
      #注意多数据源配置的时候此处为jdbc-url
      jdbc-url: jdbc:mysql://localhost:3306/firsttest?serverTimezone=UTC&useUnicode=true@characterEncoding=utf-8
      driver-class-name: com.mysql.jdbc.Driver
      type: com.alibaba.druid.pool.DruidDataSource
    remote:
      username: root
      password: root
      jdbc-url: jdbc:mysql://localhost:3306/test?serverTimezone=UTC&useUnicode=true@characterEncoding=utf-8
      driver-class-name: com.mysql.jdbc.Driver
      type: com.alibaba.druid.pool.DruidDataSource

 编写多数据源的配置类：

package com.czing.jdbcdemo.config;
 
import com.czing.jdbcdemo.mult.DataSourceType;
import com.czing.jdbcdemo.mult.DynamicDataSource;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.boot.jdbc.DataSourceBuilder;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Primary;
 
import javax.sql.DataSource;
import java.util.HashMap;
import java.util.Map; 

@Configuration
public class DataSourceConfig {
    @Bean
    @ConfigurationProperties("spring.datasource.remote")
    public DataSource remoteDataSource() {
        return DataSourceBuilder.create().build();
    }
 
    @Bean
    @ConfigurationProperties("spring.datasource.local")
    public DataSource localDataSource() {
        return DataSourceBuilder.create().build();
    }
 
    @Bean(name = "dynamicDataSource")
    @Primary
    public DynamicDataSource dataSource(DataSource remoteDataSource, DataSource localDataSource) {
        Map<Object, Object> targetDataSources = new HashMap<>();
        targetDataSources.put(DataSourceType.REMOTE.name(), remoteDataSource);
        targetDataSources.put(DataSourceType.LOCAL.name(), localDataSource);
        return new DynamicDataSource(remoteDataSource, targetDataSources);
    }
}

使用自定义注解，在查询方法的时候指定对应的数据源：

• 编写枚举类，用于指定数据源

package com.czing.jdbcdemo.mult;
 
public enum DataSourceType {
    REMOTE,
    LOCAL
}

• 数据源切换的处理类

package com.czing.jdbcdemo.mult; 

public class DynamicDataSourceContextHolder {
    /**
     * 使用ThreadLocal维护变量，ThreadLocal为每个使用该变量的线程提供独立的变量副本，
     *  所以每一个线程都可以独立地改变自己的副本，而不会影响其它线程所对应的副本。
     */
    private static final ThreadLocal<String> CONTEXT_HOLDER = new ThreadLocal<>();
 
    /**
     * 设置数据源变量
     * @param dataSourceType
     */
    public static void setDataSourceType(String dataSourceType){
        System.out.printf("切换到{%s}数据源", dataSourceType);
        CONTEXT_HOLDER.set(dataSourceType);
    }
 
    /**
     * 获取数据源变量
     * @return
     */
    public static String getDataSourceType(){
        return CONTEXT_HOLDER.get();
    }
 
    /**
     * 清空数据源变量
     */
    public static void clearDataSourceType(){
        CONTEXT_HOLDER.remove();
    }
}

• 数据源信息加载的实现

package com.czing.jdbcdemo.mult;
 
import org.springframework.jdbc.datasource.lookup.AbstractRoutingDataSource;
 
import javax.sql.DataSource;
import java.util.Map;
 

public class DynamicDataSource extends AbstractRoutingDataSource {
 
    public DynamicDataSource(DataSource defaultTargetDataSource, Map<Object, Object> targetDataSources) {
        super.setDefaultTargetDataSource(defaultTargetDataSource);
        super.setTargetDataSources(targetDataSources);
        // afterPropertiesSet()方法调用时用来将targetDataSources的属性写入resolvedDataSources中的
        super.afterPropertiesSet();
    } 
 
    /**
     * @Author wangchengzhi
     * @Description
     * 根据Key获取数据源的信息
     * @Date 23:06 2023/5/10
     * @Param
     * @return
     **/
    @Override
    protected Object determineCurrentLookupKey() {
        return DynamicDataSourceContextHolder.getDataSourceType();
    }
}

• 多数据源的配置启动类，注入数据库配置信息

package com.czing.jdbcdemo.config;
 
import com.czing.jdbcdemo.mult.DataSourceType;
import com.czing.jdbcdemo.mult.DynamicDataSource;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.boot.jdbc.DataSourceBuilder;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Primary;
 
import javax.sql.DataSource;
import java.util.HashMap;
import java.util.Map;
 

@Configuration
public class DataSourceConfig {
    @Bean
    @ConfigurationProperties("spring.datasource.remote")
    public DataSource remoteDataSource() {
        return DataSourceBuilder.create().build();
    }
 
    @Bean
    @ConfigurationProperties("spring.datasource.local")
    public DataSource localDataSource() {
        return DataSourceBuilder.create().build();
    }
 
    @Bean(name = "dynamicDataSource")
    @Primary
    public DynamicDataSource dataSource(DataSource remoteDataSource, DataSource localDataSource) {
        Map<Object, Object> targetDataSources = new HashMap<>();
        targetDataSources.put(DataSourceType.REMOTE.name(), remoteDataSource);
        targetDataSources.put(DataSourceType.LOCAL.name(), localDataSource);
        return new DynamicDataSource(remoteDataSource, targetDataSources);
    }
}

• 自定义注解

package com.czing.jdbcdemo.mult;
 
import java.lang.annotation.*;
 
@Target(ElementType.METHOD)
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface DataSource {
    /**
     * 切换数据源名称
     */
    DataSourceType value() default DataSourceType.REMOTE;
}

• AOP拦截类的实现

package com.czing.jdbcdemo.mult;
 
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.springframework.core.annotation.Order;
import org.springframework.stereotype.Component;
 
import java.lang.reflect.Method;
 
/**
 * @Description TODO
 * @Author wangchengzhi
 * @Date 2023/5/11 10:09
 */
@Aspect
@Order(1)
@Component
public class DataSourceAspect {
    @Pointcut("@annotation(com.czing.jdbcdemo.mult.DataSource)")
    public void dsPointCut() {
 
    }
 
    @Around("dsPointCut()")
    public Object around(ProceedingJoinPoint point) throws Throwable {
        MethodSignature signature = (MethodSignature) point.getSignature();
        Method method = signature.getMethod();
        DataSource dataSource = method.getAnnotation(DataSource.class);
        if (dataSource != null) {
            DynamicDataSourceContextHolder.setDataSourceType(dataSource.value().name());
        }
        try {
            return point.proceed();
        } finally {
            // 销毁数据源 在执行方法之后
            DynamicDataSourceContextHolder.clearDataSourceType();
        }
    }
}

• controller测试类的编写验证

package com.czing.jdbcdemo.controller;
 
import com.czing.jdbcdemo.mult.DataSource;
import com.czing.jdbcdemo.mult.DataSourceType;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
 
import java.util.List;
import java.util.Map;
 
@RestController
public class JDBCController {
    @Autowired
    JdbcTemplate jdbcTemplate;
 
    /**
     * @Author wangchengzhi
     * @Description
     * 使用springboot自带的jdbcTemplate实现数据库操作
     * @Date 21:34 2023/5/10
     * @Param
     * @return
     **/
    @RequestMapping("/selectTest")
    @DataSource(value=DataSourceType.LOCAL)
    public List<Map<String, Object>> getTestAccount(){
        String sql ="select * from account";
        List<Map<String, Object>> maps = jdbcTemplate.queryForList(sql);
        return maps;
    }
 
    /**
     * @Author wangchengzhi
     * @Description
     * 使用springboot自带的jdbcTemplate实现数据库操作
     * @Date 21:34 2023/5/10
     * @Param
     * @return
     **/
    @RequestMapping("/selectRemote")
    @DataSource(DataSourceType.REMOTE)
    public List<Map<String, Object>> getRemoteAccount(){
        String sql ="select * from account";
        List<Map<String, Object>> maps = jdbcTemplate.queryForList(sql);
        return maps;
    }
 
}

•  启动项目，分别访问两个接口查询不同的数据源

http://localhost:8080/selectTest 的访问数据：

 http://localhost:8080/selectRemote 的访问数据

 结语

以上为springboot实现druid配置查询的demo，并且演示了如何实现多数据源配置动态切换的代码实现，注意多数据源配置的时候url的配置为jdbc-url