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SpringBoot集成Druid连接池

关于数据库连接池

早期数据库访问（也没多少人上网）

①装载数据库驱动程序；

②通过jdbc建立数据库连接；

③访问数据库，执行sql语句；

④断开数据库连接。

对于并发量大的网站，会导致以下问题：
- 每一次web请求都要建立一次数据库连接，在同样的步骤下重复占用系统资源
- 不能控制被创建的连接对象数，系统资源会被毫无顾及的分配出去
  
  如连接过多，也可能导致内存泄漏，服务器崩溃。
数据库连接池

连接池的作用是为了提高性能，将已经创建好的连接保存在池中，当有请求来时，直接使用已经创建好的连接对Server端进行访问。

这样省略（复用）了创建连接和销毁连接的过程（TCP连接建立时的三次握手和销毁时的四次握手），从而在性能上得到了提高。
嚣张的Druid（GitHub的Wiki上自称是Java语言最好的数据库连接池）

集成Druid

在上次Thymeleaf基础上进行集成

https://www.cnblogs.com/noneplus/p/11528129.html

引入pom

<!-- https://mvnrepository.com/artifact/com.alibaba/druid -->
<dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>druid</artifactId>
    <version>1.1.20</version>
</dependency>

yaml

spring:
  datasource:
    #   数据源基本配置
    username: noneplus
    password: Noneplus564925080!
    driver-class-name: com.mysql.cj.jdbc.Driver
    url: jdbc:mysql://47.103.6.247:3306/user?serverTimezone=UTC
    type: com.alibaba.druid.pool.DruidDataSource
    #   Druid数据源配置
    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
    #   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,wall,log4j
    maxPoolPreparedStatementPerConnectionSize: 20
    useGlobalDataSourceStat: true
    connectionProperties: druid.stat.mergeSql=true;druid.stat.slowSqlMillis=500
  thymeleaf:
    cache: false
pagehelper:
  helperDialect: mysql
  reasonable: true
  supportMethodsArguments: true
  pageSizeZero: false #pageSize=0

DruidConfig

package zkrun.top.web.config;


import com.alibaba.druid.pool.DruidDataSource;
import com.alibaba.druid.support.http.StatViewServlet;
import com.alibaba.druid.support.http.WebStatFilter;
import org.springframework.boot.context.properties.ConfigurationProperties;
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 javax.sql.DataSource;
import java.util.Arrays;
import java.util.HashMap;
import java.util.Map;

@Configuration
public class DruidConfig {

    //加载application.yaml中的Druid配置
    @ConfigurationProperties(prefix = "spring.datasource")
    @Bean
    public DataSource druid(){
        return  new DruidDataSource();
    }

    //配置Druid的监控
    //1、配置一个管理后台的Servlet
    @Bean
    public ServletRegistrationBean statViewServlet(){
        ServletRegistrationBean bean = new ServletRegistrationBean(new StatViewServlet(), "/druid/*");
        Map<String,String> initParams = new HashMap<>();

        initParams.put("loginUsername","hq");
        initParams.put("loginPassword","564925080");
        initParams.put("allow","");//默认就是允许所有访问
        initParams.put("deny","192.168.15.21");

        bean.setInitParameters(initParams);
        return bean;
    }


    //2、配置一个web监控的filter
    @Bean
    public FilterRegistrationBean webStatFilter(){
        FilterRegistrationBean bean = new FilterRegistrationBean();
        bean.setFilter(new WebStatFilter());

        Map<String,String> initParams = new HashMap<>();
        initParams.put("exclusions","*.js,*.css,/druid/*");

        bean.setInitParameters(initParams);

        bean.setUrlPatterns(Arrays.asList("/*"));

        return  bean;
    }
}

log4j

<dependency>
            <groupId>log4j</groupId>
            <artifactId>log4j</artifactId>
            <version>1.2.17</version>
        </dependency>

测试

访问：

http://localhost:8080/druid/

SpringBoot集成Druid连接池

实时监控：

SpringBoot集成Druid连接池

数据源配置文件密码加密显示

找到jar包，在终端打开：

SpringBoot集成Druid连接池

生成密码

java -cp druid-1.0.16.jar com.alibaba.druid.filter.config.ConfigTools yourPassword

其中druid-1.0.16.jar换成正在使用对应的版本，yourPassword改成数据库连接的密码。

生成privateKey和publicKey以及password

privateKey:MIIBVAIBADANBgkqhkiG9w0BAQEFAASCAT4wggE6AgEAAkEAgiX0+n2diIixWASA642qrI8hTo2xg1LItfeDFwGEg9G1wvlarF69gq+wDBpPhY63DDbry8d3I/vNZMaG0bGxwwIDAQABAkAQfiDiUWLSN4hJwCBaOVSkk2rEGp6hJq
96p8f79VxGm/FneqyzLgiIQvvIutsOWSSQses+C/cDoXYEgfddieSpAiEAuq1lcFuBPh7MWZwlbIi0GM4+/1tNQed+W9Lm3qGJYk0CIQCyepaXbrY8Vk8pUZMOKr74kFFBfG5WqbAJuNYym1PMTwIgZttPfx8METxLADzm6exQvzI0x+J4qQ1yNAn
6p0R+PCkCIFPZ8EI5C3kRe6OH5bT0NECHXQWNNjGVC1Wl90xTWW1VAiEAnKdXLI45e1e8jgpCQ4TG90PmDlKlrcxUnBiHUrOhyew=
publicKey:MFwwDQYJKoZIhvcNAQEBBQADSwAwSAJBAIIl9Pp9nYiIsVgEgOuNqqyPIU6NsYNSyLX3gxcBhIPRtcL5WqxevYKvsAwaT4WOtww268vHdyP7zWTGhtGxscMCAwEAAQ==
password:MEMMpYHaOUFVuaR37bMbUmGW76WVSLAD7pnFLrbup5H4Q6sZvWMDsYAcnZvAL2hY2Man1rc6SCJMYwrse1xPKw==

yaml配置

修改password，添加公钥。

spring:
  datasource:
    #   数据源基本配置
    username: noneplus
    password: MEMMpYHaOUFVuaR37bMbUmGW76WVSLAD7pnFLrbup5H4Q6sZvWMDsYAcnZvAL2hY2Man1rc6SCJMYwrse1xPKw==   # 1.配置生成的password
    driver-class-name: com.mysql.cj.jdbc.Driver
    url: jdbc:mysql://47.103.6.247:3306/user?serverTimezone=UTC
    type: com.alibaba.druid.pool.DruidDataSource
    #   Druid数据源配置
    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
    #   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,wall,log4j,config  # 3.添加config
    maxPoolPreparedStatementPerConnectionSize: 20
    useGlobalDataSourceStat: true
    # 2.开启加密，配置公钥
    connectionProperties: druid.stat.mergeSql=true;druid.stat.slowSqlMillis=500;config.decrypt=true;config.decrypt.key=MFwwDQYJKoZIhvcNAQEBBQADSwAwSAJBAIIl9Pp9nYiIsVgEgOuNqqyPIU6NsYNSyLX3gxcBhIPRtcL5WqxevYKvsAwaT4WOtww268vHdyP7zWTGhtGxscMCAwEAAQ==
  thymeleaf:
    cache: false
pagehelper:
  helperDialect: mysql
  reasonable: true
  supportMethodsArguments: true
  pageSizeZero: false #pageSize=0