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 (SQLEx