Spring Boot 使用Druid详解

Druid是Java语言中最好的数据库连接池，并且能够提供强大的监控和扩展功能，下面来说明如何在 SpringBoot 中配置使用Druid。
步骤：

1. 在pom.xml中加载依赖

2. 在application.properties中加入数据源配置

3. 编写DruidConfiguration，通过@Bean注解的方式注入druid servlet和filter，以便提供监控页面访问

4. 浏览器访问

一、在pom.xml中加入依赖

<dependency>
      <groupId>com.alibaba</groupId>
      <artifactId>druid</artifactId>
      <version>1.0.18</version>
  </dependency> 

二、在application.properties中加入数据源配置

################## server ################################
server.port=8080 

################## datasource ################################
spring.datasource.url = jdbc:mysql://localhost:3306/spring
spring.datasource.username = root
spring.datasource.password = 123456
spring.datasource.driverClassName = com.mysql.jdbc.Driver 

#使用Druid数据源
spring.datasource.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
spring.datasource.initialSize=5
spring.datasource.minIdle=5
spring.datasource.maxActive=20 

# 配置获取连接等待超时的时间
spring.datasource.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
spring.datasource.timeBetweenEvictionRunsMillis=60000 

# 配置一个连接在池中最小生存的时间，单位是毫秒
spring.datasource.minEvictableIdleTimeMillis=300000
spring.datasource.validationQuery=SELECT 1 FROMDUAL
spring.datasource.testWhileIdle=true
spring.datasource.testOnBorrow=false
spring.datasource.testOnReturn=false 

# 打开PSCache，并且指定每个连接上PSCache的大小
spring.datasource.poolPreparedStatements=true
spring.datasource.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
spring.datasource.filters=stat,wall,log4j 

# 通过connectProperties属性来打开mergeSql功能；慢SQL记录
spring.datasource.connectionProperties=druid.stat.mergeSql=true;druid.stat.slowSqlMillis=5000 

# 合并多个DruidDataSource的监控数据
#spring.datasource.useGlobalDataSourceStat=true 

################ Java Persistence Api ###########################
# Specify the DBMS
spring.jpa.database = MYSQL
# Show or not log for each sql query
spring.jpa.show-sql = true
# Hibernate ddl auto (create, create-drop, update)
spring.jpa.hibernate.ddl-auto = update
#[org.hibernate.cfg.ImprovedNamingStrategy #org.hibernate.cfg.DefaultNamingStrategy]
spring.jpa.hibernate.naming-strategy = org.hibernate.cfg.ImprovedNamingStrategy
# stripped before adding them to the entity manager)
spring.jpa.properties.hibernate.dialect= org.hibernate.dialect.MySQL5Dialect 

#暂时不用redis，所以none，spring.session.store-type=reids
spring.session.store-type=none

以上是我项目中的配置信息，大家只要关注datasource部分即可。

三、编写DruidConfiguration配置类，通过@Bean注解的方式注入druid servlet和filter，以便提供监控页面访问

package com.example.config; 

import java.sql.SQLException; 

import javax.sql.DataSource; 

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Value;
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 com.alibaba.druid.pool.DruidDataSource;
import com.alibaba.druid.support.http.StatViewServlet;
import com.alibaba.druid.support.http.WebStatFilter; 

/**
 * 配置druid数据源
 *
 */
@Configuration
public class DruidConfiguration { 

  private Logger logger = LoggerFactory.getLogger(DruidConfiguration.class); 

  @Bean
  public ServletRegistrationBean druidStatViewServlet() {
    ServletRegistrationBean registrationBean = new ServletRegistrationBean(new StatViewServlet(), "/druid/*");
    registrationBean.addInitParameter("allow", "127.0.0.1");
    registrationBean.addInitParameter("deny", "192.168.31.234");
    registrationBean.addInitParameter("loginUsername", "admin");
    registrationBean.addInitParameter("loginPassword", "123456");
    registrationBean.addInitParameter("resetEnable", "false"); 

    return registrationBean;
  } 

  @Bean
  public FilterRegistrationBean druidWebStatViewFilter() {
    FilterRegistrationBean registrationBean = new FilterRegistrationBean(new WebStatFilter());
    registrationBean.addInitParameter("urlPatterns", "/*");
    registrationBean.addInitParameter("exclusions", "*.js,*.gif,*.jpg,*.bmp,*.png,*.css,*.ico,/druid/*"); 

    return registrationBean; 

  } 

  @Bean
  public DataSource druidDataSource(@Value("${spring.datasource.url}") String url,
      @Value("${spring.datasource.driverClassName}") String driver,
      @Value("${spring.datasource.username}") String userName,
      @Value("${spring.datasource.password}") String password,
      @Value("${spring.datasource.maxActive}") int maxActive,
      @Value("${spring.datasource.filters}") String filters,
      @Value("${spring.datasource.initialSize}")
      int initialSize,
      @Value("${spring.datasource.minIdle}")
      int minIdle,
      @Value("${spring.datasource.maxWait}")
      int maxWait,
      @Value("${spring.datasource.timeBetweenEvictionRunsMillis}")
      int timeBetweenEvictionRunsMillis,
      @Value("${spring.datasource.minEvictableIdleTimeMillis}")
      int minEvictableIdleTimeMillis,
      @Value("${spring.datasource.validationQuery}")
      String validationQuery,
      @Value("${spring.datasource.testWhileIdle}")
      boolean testWhileIdle,
      @Value("${spring.datasource.testOnBorrow}")
      boolean testOnBorrow,
      @Value("${spring.datasource.testOnReturn}")
      boolean testOnReturn,
      @Value("${spring.datasource.poolPreparedStatements}")
      boolean poolPreparedStatements,
      @Value("${spring.datasource.maxPoolPreparedStatementPerConnectionSize}")
      int maxPoolPreparedStatementPerConnectionSize,
      @Value("${spring.datasource.connectionProperties}")
      String connectionProperties,
      @Value("${spring.datasource.useGlobalDataSourceStat}")
      boolean useGlobalDataSourceStat 

  ) {
    DruidDataSource dataSource = new DruidDataSource();
    /*数据源主要配置*/
    dataSource.setUrl(url);
    dataSource.setDriverClassName(driver);
    dataSource.setUsername(userName);
    dataSource.setPassword(password); 

    /*数据源补充配置*/
    dataSource.setMaxActive(maxActive);
    dataSource.setInitialSize(initialSize);
    dataSource.setMinIdle(minIdle);
    dataSource.setMaxWait(maxWait);
    dataSource.setTimeBetweenEvictionRunsMillis(timeBetweenEvictionRunsMillis);
    dataSource.setMinEvictableIdleTimeMillis(minEvictableIdleTimeMillis);
    dataSource.setValidationQuery(validationQuery);
    dataSource.setTestOnBorrow(testOnBorrow);
    dataSource.setTestOnReturn(testOnReturn);
    dataSource.setTestWhileIdle(testWhileIdle);
    dataSource.setPoolPreparedStatements(poolPreparedStatements);
    dataSource.setMaxPoolPreparedStatementPerConnectionSize(maxPoolPreparedStatementPerConnectionSize);
    dataSource.setConnectionProperties(connectionProperties);
    dataSource.setUseGlobalDataSourceStat(useGlobalDataSourceStat); 

    try {
      dataSource.setFilters(filters);
      logger.info("Druid数据源初始化设置成功......");
    } catch (SQLException e) {
      e.printStackTrace();
      logger.info("Druid数据源filters设置失败......");
    }
    return dataSource; 

  }
}

四、浏览器访问

在浏览器中输入http://localhost:8080/druid/index.html，首次访问需要使用账号和密码登录

在数据源一栏中，所有加"*"标识的都不能为空，，尤其是filter类名，否则会看不到SQL监控数据。

五、查看SQL监控

执行删除某条记录后，查看SQL监控

到这里，我们就把druid配置成功了。

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持我们。