springboot 中使用Druid 数据源提供数据库监控

一、springboot 中注册 Servlet/Filter/Listener 的方式有两种，1 通过代码注册 ServletRegistrationBean、 FilterRegistrationBean 和 ServletListenerRegistrationBean 。

2 通过注解的方式，在 SpringBootApplication 上使用@ServletComponentScan 注解后，Servlet、Filter、Listener 可以直接通过 @WebServlet、@WebFilter、@WebListener 注解自动注册，无需其他代码。

二、配置springboot 项目使用Druid 数据源，好处就不多说了，百度一下很多。配置步骤，本机使用maven配置

2.1 引入依赖，完整的pom文件如下

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
  <modelVersion>4.0.</modelVersion>
  <groupId>com.huitong</groupId>
  <artifactId>demo1</artifactId>
  <packaging>jar</packaging>
  <version>1.0-SNAPSHOT</version>
  <name>demo1 Maven Webapp</name>
  <url>http://maven.apache.org</url>

  <parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>2.0..RELEASE</version>
  </parent>

  <properties>
    <java.version>1.8</java.version>
    <mybatis.spring.boot.version>1.3.</mybatis.spring.boot.version>
    <springfox-swagger.version>2.8.</springfox-swagger.version>
    <swagger-bootstrap-ui.version>1.7.</swagger-bootstrap-ui.version>
    <druid.version>1.1.</druid.version>

  </properties>

  <dependencies>

    <dependency>
      <groupId>com.alibaba</groupId>
      <artifactId>druid</artifactId>
      <version>${druid.version}</version>
    </dependency>

    <!-- https://mvnrepository.com/artifact/io.springfox/springfox-swagger2 -->
    <dependency>
      <groupId>io.springfox</groupId>
      <artifactId>springfox-swagger2</artifactId>
      <version>${springfox-swagger.version}</version>
    </dependency>

    <!-- https://mvnrepository.com/artifact/io.springfox/springfox-swagger-ui -->
    <dependency>
      <groupId>io.springfox</groupId>
      <artifactId>springfox-swagger-ui</artifactId>
      <version>${springfox-swagger.version}</version>
    </dependency>

    <!-- https://mvnrepository.com/artifact/com.github.xiaoymin/swagger-bootstrap-ui -->
    <dependency>
      <groupId>com.github.xiaoymin</groupId>
      <artifactId>swagger-bootstrap-ui</artifactId>
      <version>${swagger-bootstrap-ui.version}</version>
    </dependency>

    <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-web</artifactId>
    </dependency>

    <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-test</artifactId>
      <scope>test</scope>
    </dependency>

    <dependency>
      <groupId>mysql</groupId>
      <artifactId>mysql-connector-java</artifactId>
    </dependency>

    <!-- https://mvnrepository.com/artifact/org.mybatis.spring.boot/mybatis-spring-boot-starter -->
    <dependency>
      <groupId>org.mybatis.spring.boot</groupId>
      <artifactId>mybatis-spring-boot-starter</artifactId>
      <version>${mybatis.spring.boot.version}</version>
    </dependency>

    <!--&lt;!&ndash; 添加缓存支持 &ndash;&gt;-->
    <!--<dependency>-->
      <!--<groupId>org.springframework.boot</groupId>-->
      <!--<artifactId>spring-boot-starter-cache</artifactId>-->
    <!--</dependency>-->

    <!-- 添加 redis 缓存支持 -->
    <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-data-redis</artifactId>
    </dependency>

    <!-- 添加邮件支持 -->
    <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-mail</artifactId>
    </dependency>

    <dependency>
      <groupId>com.jayway.jsonpath</groupId>
      <artifactId>json-path</artifactId>
    </dependency>

    <dependency>
      <groupId>org.projectlombok</groupId>
      <artifactId>lombok</artifactId>
    </dependency>

    <!-- https://mvnrepository.com/artifact/org.apache.commons/commons-lang3 -->
    <dependency>
      <groupId>org.apache.commons</groupId>
      <artifactId>commons-lang3</artifactId>
    </dependency>

    <!-- https://mvnrepository.com/artifact/org.apache.httpcomponents/httpclient -->
    <dependency>
      <groupId>org.apache.httpcomponents</groupId>
      <artifactId>httpclient</artifactId>
    </dependency>

    <!-- Spring boot 热启动依赖 -->
    <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-devtools</artifactId>
      <optional>true</optional>
    </dependency>

  </dependencies>

  <build>
    <finalName>demo1</finalName>
    <resources>
      <resource>
        <directory>src/main/resources</directory>
        <includes>
          <include>**/*.xml</include>
          <include>**/*.properties</include>
        </includes>
      </resource>

      <resource>
        <directory>src/main/java</directory>
        <includes>
          <include>**/*.xml</include>
          <include>**/*.properties</include>
        </includes>
      </resource>
    </resources>

    <!--spring boot maven的构造插件-->
    <plugins>
      <plugin>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-maven-plugin</artifactId>
        <configuration>
          <fork>true</fork>
        </configuration>
      </plugin>

      <plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-compiler-plugin</artifactId>
        <configuration>
          <source>${java.version}</source>
          <target>${java.version}</target>
          <testSource>${java.version}</testSource>
          <testTarget>${java.version}</testTarget>
        </configuration>
      </plugin>

    </plugins>
  </build>

</project>

需要引入：mysql-connector-java，druid，

2.2 配置数据源 application.properties

#数据库配置
# 驱动配置信息
spring.datasource.type=com.alibaba.druid.pool.DruidDataSource
spring.datasource.url=jdbc:mysql://localhost:3306/demo1?useUnicode=true&characterEncoding=UTF-8&useSSL=false&zeroDateTimeBehavior=convertToNull
spring.datasource.username=root
spring.datasource.password=test
spring.datasource.driver-class-name=com.mysql.jdbc.Driver

# 连接池的配置信息
# 初始化大小，最小，最大
spring.datasource.initialSize=
spring.datasource.minIdle=
spring.datasource.maxActive=

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

# 配置一个连接在池中最小生存的时间，单位是毫秒
spring.datasource.minEvictableIdleTimeMillis=
spring.datasource.validationQuery=SELECT  FROM DUAL
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=
# 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
# 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=

#mybatis 配置

#扫描映射文件
mybatis.mapper-locations=classpath*:com/huitong/**/mapper/*.xml

2.3 配置 web 监控，使用注解的方式注册 监控显示Servlet 和 采集web-jdbc关联监控的数据的Filter，

2.3.1 数据源配置

import com.alibaba.druid.pool.DruidDataSource;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
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 javax.sql.DataSource;
import java.sql.SQLException;

@Configuration
public class DruidDBConfig {

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

    @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 声明，DataSource 对象为 Spring 容器所管理;
     * @Primary 表示这里定义的DataSource将覆盖其他来源的DataSource。
     * StatFilter，用于统计监控信息。StatFilter的别名是stat。
     * 统计SQL信息，合并统计。mergeStat是的MergeStatFilter缩写。
     *     通过 DataSource 的属性<property name="filters" value="mergeStat" /> 或者
     *                          connectProperties属性来打开mergeSql功能 <property name="connectionProperties" value="druid.stat.mergeSql=true" />
     * StatFilter属性slowSqlMillis用来配置SQL慢的标准
     *
     * @return
     */
    @Bean
    @Primary
    public DataSource dataSource() {
        DruidDataSource datasource = new DruidDataSource();
        datasource.setUrl(dbUrl);
        datasource.setDriverClassName(driverClassName);
        datasource.setUsername(username);
        datasource.setPassword(password);

        //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 {
            /**
             * 设置StatFilter，用于统计监控信息。
             * StatFilter的别名是stat
             *
             */
            datasource.setFilters(filters);
        } catch (SQLException e) {
            logger.error("druid configuration initialization filter : {0}",e);
        }
        datasource.setConnectionProperties(connectionProperties);

        return datasource;
    }

}

2.3.2 通过注解的方式配置监控显示页面 Servlet

import com.alibaba.druid.support.http.StatViewServlet;

import javax.servlet.annotation.WebInitParam;
import javax.servlet.annotation.WebServlet;

/**
 * StatViewServlet用于展示Druid的统计信息。
 * 提供监控信息展示的html页面
 * 提供监控信息的JSON API
 *
 * 内置监控页面的首页是/druid/index.html
 *
 */

/**
 * @Webservlet
 * 有两个属性可以用来表示Servlet的访问路径，分别是value和urlPatterns。value和urlPatterns都是数组形式，
 * 表示我们可以把一个Servlet映射到多个访问路径，但是value和urlPatterns不能同时使用。
 *
 */
@WebServlet(
        urlPatterns = {"/druid/*"},
        initParams = {
                @WebInitParam(name = "loginUsername", value = "admin"),
                @WebInitParam(name = "loginPassword", value = "test"),
                @WebInitParam(name = "resetEnable", value = "false")
//      @WebInitParam(name = "allow", value = "127.0.0.1")
    }
)
public class DruidStatViewServlet extends StatViewServlet {
}

2.3.3 通过注解的方式配置采集Filter

import com.alibaba.druid.support.http.WebStatFilter;

import javax.servlet.annotation.WebFilter;
import javax.servlet.annotation.WebInitParam;

/**
 * WebStatFilter用于采集web-jdbc关联监控的数据。
 * 属性filterName声明过滤器的名称,可选
 * 属性urlPatterns指定要过滤 的URL模式,也可使用属性value来声明.(指定要过滤的URL模式是必选属性)
 */

@WebFilter(
        urlPatterns = "/demo1/*",
        initParams = {
                @WebInitParam(name = "exclusions",value = "*.js,*.gif,*.jpg,*.png,*.css,*.ico,/druid/*")
        }
)
public class DruidStatFilter extends WebStatFilter {
}

2.4 使应用开启扫描注册功能

//    开启组件扫描和自动配置
//    mapper 扫描 mapper 接口
@SpringBootApplication
@MapperScan(basePackages = {"com.huitong.**.mapper"})
@ServletComponentScan(basePackages = {"com.huitong.**.config"})
public class Demo1Application {

    public static void main(String[] args) {
        SpringApplication.run(Demo1Application.class, args);//负责启动引导应用程序
    }
}

2.5 此时配置完成，如果应用搞完就可以测试了。启动应用后在浏览器中输入 http://localhost:8080/druid/index.html

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