springboot druid监控

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Druid它好在哪：

它可以提供数据源、sql防火墙，web应用，URI监控、Session监控，spring监控等。

方便进行针对性改造和优化，提高项目性能。

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如下是实现的具体操作：

一、引入依赖

    <dependency>
        <groupId>com.alibaba</groupId>
        <artifactId>druid</artifactId>
        <version>1.0.28</version>
    </dependency>

二、配置文件（spring.datasource 下的配置）

    #配置druid监控参数
    type: com.alibaba.druid.pool.DruidDataSource
    initialSize: 5
    minIdle: 5
    maxActive: 20
    maxWait: 60000
    timeBetweenEvictionRunsMillis: 60000
    minEvictableIdleTimeMillis: 300000
    validationQuery: SELECT 1 FROM DUAL
    testWhileIdle: true
    testOnBorrow: false
    testOnReturn: false
    poolPreparedStatements: true
    maxPoolPreparedStatementPerConnectionSize: 20
    filters: stat,wall,log4j

三、三个关键类（没有试是否可以省略）

(1)DruidConfig

import java.sql.SQLException;
import javax.sql.DataSource;
import org.apache.log4j.Logger;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Primary;
import com.alibaba.druid.pool.DruidDataSource;

@Configuration
public class DruidConfig {
 private Logger logger = Logger.getLogger(this.getClass());

 @Value("${spring.datasource.url}")
 private String dbUrl;

 @Value("${spring.datasource.username}")
 private String username;

 @Value("${spring.datasource.password}")
 private String password;

 @Value("${spring.datasource.driver-class-name}")
 private String driverClassName;

 @Value("${spring.datasource.initialSize}")
 private int initialSize;

 @Value("${spring.datasource.minIdle}")
 private int minIdle;

 @Value("${spring.datasource.maxActive}")
 private int maxActive;

 @Value("${spring.datasource.maxWait}")
 private int maxWait;

 @Value("${spring.datasource.timeBetweenEvictionRunsMillis}")
 private int timeBetweenEvictionRunsMillis;

 @Value("${spring.datasource.minEvictableIdleTimeMillis}")
 private int minEvictableIdleTimeMillis;

 @Value("${spring.datasource.validationQuery}")
 private String validationQuery;

 @Value("${spring.datasource.testWhileIdle}")
 private boolean testWhileIdle;

 @Value("${spring.datasource.testOnBorrow}")
 private boolean testOnBorrow;

 @Value("${spring.datasource.testOnReturn}")
 private boolean testOnReturn;

 @Value("${spring.datasource.poolPreparedStatements}")
 private boolean poolPreparedStatements;

 @Value("${spring.datasource.maxPoolPreparedStatementPerConnectionSize}")
 private int maxPoolPreparedStatementPerConnectionSize;

 @Value("${spring.datasource.filters}")
 private String filters;

 @Value("{spring.datasource.connectionProperties}")
 private String connectionProperties;

 @Bean
 @Primary //主数据源
 public DataSource dataSource(){
  DruidDataSource datasource = new DruidDataSource();
  datasource.setUrl(this.dbUrl);
  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) {
   logger.error("druid configuration Exception", e);
  }
  datasource.setConnectionProperties(connectionProperties);
  return datasource;
 }
}

(2)DruidFilter

import javax.servlet.annotation.WebFilter;
import javax.servlet.annotation.WebInitParam;
import com.alibaba.druid.support.http.WebStatFilter;

@WebFilter(filterName="druidWebStatFilter",urlPatterns="/*",
  initParams={
    @WebInitParam(name="exclusions",value="*.js,*.gif,*.jpg,*.bmp,*.png,*.css,*.ico,/druid/*")//忽略资源
  }
)
public class DruidFilter extends WebStatFilter {
}

(3)DruidServlet

import javax.servlet.annotation.WebInitParam;
import javax.servlet.annotation.WebServlet;
import com.alibaba.druid.support.http.StatViewServlet;

@WebServlet(urlPatterns="/druid/*",
  initParams={
    @WebInitParam(name="allow",value=""),// IP白名单(没有配置或者为空，则允许所有访问)
    @WebInitParam(name="deny",value=""),// IP黑名单 (deny优先于allow)
    @WebInitParam(name="loginUsername",value="admin"),// 登录druid管理页面用户名
    @WebInitParam(name="loginPassword",value="admin")// 登录druid管理页面密码
  })
public class DruidServlet extends StatViewServlet {

}

四、最后别忘了在启动类上加入注解@ServletComponentScan，让项目扫描到servlet。（一般都会加过了）

五、看看效果

访问页面http://127.0.0.1:8080/{projectName}/druid/index.html就可以访问监控页面了，druid已经将数据友好的显示到页面上了，包括每条sql执行的次数，执行的时间，最慢时间等等很多详细信息，供我们参考，找到哪些执行效率低的耗时长的语句进行优化。同时提供数据源、sql防火墙，web应用，URI监控、Session监控，spring监控等。
如图：可以看到第一个sql执行的慢并且被调用的次数多，

可以针对地优化一下了。

image.png