Spring官方文档给出了多数据配置示例（https://docs.spring.io/spring-boot/docs/2.4.2/reference/htmlsingle/#howto-two-datasources），但是比如用默认的HikariCP（https://github.com/brettwooldridge/HikariCP），对一些优化配置参数并不能生效。

默认单数据源配置

spring: 
  datasource:
    type: com.zaxxer.hikari.HikariDataSource
    hikari:
      data-source-properties:
        cachePrepStmts: true
        prepStmtCacheSize: 500
        prepStmtCacheSqlLimit: 2048
        useServerPrepStmts: true
        rewriteBatchedStatements: true
        cacheResultSetMetadata: true
        cacheServerConfiguration: true
        elideSetAutoCommits: true
        maintainTimeStats: false

下面的例子，提供了多数据源情况下，如何配置HikariCP的DataSourceProperties。

自定义HikariCP的DataSourceProperties的Configuration Properties

import java.util.Map;

import org.springframework.boot.context.properties.ConfigurationProperties;

@ConfigurationProperties(prefix = "spring.datasource.hikari")
public class HikariProperties {
    private Map<String, Object> dataSourceProperties;

    public Map<String, Object> getDataSourceProperties() {
        return dataSourceProperties;
    }

    public void setDataSourceProperties(Map<String, Object> dataSourceProperties) {
        this.dataSourceProperties = dataSourceProperties;
    }
}

在Application中激活上面的配置

import org.springframework.beans.factory.annotation.Value;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.context.properties.EnableConfigurationProperties;
import org.springframework.cache.annotation.EnableCaching;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.web.reactive.function.client.WebClient;

import cn.ydyun360.common.config.HikariProperties;

@EnableDiscoveryClient
@SpringBootApplication
@EnableCaching
@EnableConfigurationProperties(HikariProperties.class)
@ComponentScan("")
public class Application {
    public static void main(String[] args) {
        SpringApplication.run(Application.class, args);
    }
}

job数据源配置

import org.springframework.boot.autoconfigure.jdbc.DataSourceProperties;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Primary;
import org.springframework.jdbc.core.JdbcTemplate;

import com.zaxxer.hikari.HikariDataSource;

import cn.ydyun360.common.config.HikariProperties;

@Configuration
public class JobJpaConfig {
    @Bean
    @ConfigurationProperties("spring.datasource.job")
    @Primary
    public DataSourceProperties jobDataSourceProperties() {
        return new DataSourceProperties();
    }

    @Bean(name = "jobDataSource")
    @ConfigurationProperties("spring.datasource.job.configuration")
    @Primary
    public HikariDataSource jobDataSource(HikariProperties hikariProperties) {
        var dataSource = jobDataSourceProperties().initializeDataSourceBuilder().type(HikariDataSource.class).build();

        for (var entry : hikariProperties.getDataSourceProperties().entrySet()) {
            dataSource.addDataSourceProperty(entry.getKey(), entry.getValue());
        }

        return dataSource;
    }

    @Bean(name = "jobJdbcTemplate")
    @Primary
    public JdbcTemplate jdbcTemplate(HikariProperties hikariProperties) {
        var ds = jobDataSource(hikariProperties);

        return new JdbcTemplate(ds);
    }

}

goods数据源配置

import org.springframework.boot.autoconfigure.jdbc.DataSourceProperties;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.jdbc.core.namedparam.NamedParameterJdbcTemplate;

import com.zaxxer.hikari.HikariDataSource;

import cn.ydyun360.common.config.HikariProperties;

@Configuration
public class GoodsJpaConfig {
    @Bean
    @ConfigurationProperties("spring.datasource.goods")
    public DataSourceProperties goodsDataSourceProperties() {
        return new DataSourceProperties();
    }

    @Bean(name = "goodsDataSource")
    @ConfigurationProperties("spring.datasource.goods.configuration")
    public HikariDataSource goodsDataSource(HikariProperties hikariProperties) {
        var dataSource = goodsDataSourceProperties().initializeDataSourceBuilder().type(HikariDataSource.class).build();

        for (var entry : hikariProperties.getDataSourceProperties().entrySet()) {
            dataSource.addDataSourceProperty(entry.getKey(), entry.getValue());
        }

        return dataSource;
    }

    @Bean(name = "goodsJdbcTemplate")
    public JdbcTemplate jdbcTemplate(HikariProperties hikariProperties) {
        return new JdbcTemplate(goodsDataSource(hikariProperties));
    }

    @Bean(name = "goodsNamedParameterJdbcTemplate")
    public NamedParameterJdbcTemplate goodsNamedParameterJdbcTemplate(HikariProperties hikariProperties) {
        return new NamedParameterJdbcTemplate(jdbcTemplate(hikariProperties));
    }

}

配置文件

spring: 
  datasource:
    type: com.zaxxer.hikari.HikariDataSource
    hikari:
      data-source-properties:
        cachePrepStmts: true
        prepStmtCacheSize: 500
        prepStmtCacheSqlLimit: 2048
        useServerPrepStmts: true
        rewriteBatchedStatements: true
        cacheResultSetMetadata: true
        cacheServerConfiguration: true
        elideSetAutoCommits: true
        maintainTimeStats: false
    job:
      driverClassName: com.mysql.cj.jdbc.Driver
    goods:
      driverClassName: com.mysql.cj.jdbc.Driver