三、springboot + jpa配置druid

一、导入包build.gradle引入

implementation group:'com.alibaba', name: 'druid', version: '1.1.6'

二、配置文件application.yml中配置

server:
  port: 8083
spring:
  datasource:
    driver-class-name: org.postgresql.Driver
    url: jdbc:postgresql://localhost:5432/firstproject
    username: postgres
    password: 123456
    type: com.alibaba.druid.pool.DruidDataSource
    # 下面为连接池的补充设置，应用到上面所有数据源中
    # 初始化大小，最小，最大
    initialSize: 1
    minIdle: 3
    maxActive: 20
    # 配置获取连接等待超时的时间
    maxWait: 60000
    # 配置间隔多久才进行一次检测，检测需要关闭的空闲连接，单位是毫秒
    timeBetweenEvictionRunsMillis: 60000
    # 配置一个连接在池中最小生存的时间，单位是毫秒
    minEvictableIdleTimeMillis: 30000
    validationQuery: select 'x'
    testWhileIdle: true
    testOnBorrow: false
    testOnReturn: false
    # 打开PSCache，并且指定每个连接上PSCache的大小
    poolPreparedStatements: true
    maxPoolPreparedStatementPerConnectionSize: 20
    # 配置监控统计拦截的filters，去掉后监控界面sql无法统计，'wall'用于防火墙
    filters: stat,slf4j
    # 通过connectProperties属性来打开mergeSql功能；慢SQL记录
    connectionProperties: druid.stat.mergeSql=true;druid.stat.slowSqlMillis=5000
    platform: postgresql
    # 合并多个DruidDataSource的监控数据
    #useGlobalDataSourceStat: true
    packages.to.scan: com.zz.firstproject

三、添加配置文件DruidConfig.java

import com.alibaba.druid.pool.DruidDataSource;
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 javax.sql.DataSource;
import java.sql.SQLException;

/**
 * Druid数据源连接池配置
 */
@Configuration
public class DruidConfig {

    private static final String DB_PREFIX = "spring.datasource";

    @ConfigurationProperties(prefix = DB_PREFIX)
    class IDataSourceProperties {
        private String url;
        private String username;
        private String password;
        private String driverClassName;
        private int initialSize;
        private int minIdle;
        private int maxActive;
        private int maxWait;
        private int timeBetweenEvictionRunsMillis;
        private int minEvictableIdleTimeMillis;
        private String validationQuery;
        private boolean testWhileIdle;
        private boolean testOnBorrow;
        private boolean testOnReturn;
        private boolean poolPreparedStatements;
        private int maxPoolPreparedStatementPerConnectionSize;
        private String filters;
        private String connectionProperties;

        @Bean     //声明其为Bean实例
        @Primary  //在同样的DataSource中，首先使用被标注的DataSource
        public DataSource dataSource() {
            DruidDataSource datasource = new DruidDataSource();
            datasource.setUrl(url);
            datasource.setUsername(username);
            datasource.setPassword(password);
            datasource.setDriverClassName(driverClassName);

            //configuration
            datasource.setInitialSize(initialSize);
            datasource.setMinIdle(minIdle);
            datasource.setMaxActive(maxActive);
            datasource.setMaxWait(maxWait);
            datasource.setTimeBetweenEvictionRunsMillis(timeBetweenEvictionRunsMillis);
            datasource.setMinEvictableIdleTimeMillis(minEvictableIdleTimeMillis);
            datasource.setValidationQuery(validationQuery);
            datasource.setTestWhileIdle(testWhileIdle);
            datasource.setTestOnBorrow(testOnBorrow);
            datasource.setTestOnReturn(testOnReturn);
            datasource.setPoolPreparedStatements(poolPreparedStatements);
            datasource.setMaxPoolPreparedStatementPerConnectionSize(maxPoolPreparedStatementPerConnectionSize);
            try {
                datasource.setFilters(filters);
            } catch (SQLException e) {
                System.err.println("druid configuration initialization filter: " + e);
            }
            datasource.setConnectionProperties(connectionProperties);
            return datasource;
        }

    get()/set()方法在此省略，手动添加
    }
}

四、测试的时候只需要在return datasource;之前，system.out.println()打印出datasource设置进去的一些值，前中后三个即可，在启动项目的时候就会打印出来