SpringBoot整合Druid实现数据库连接池和监控

<!-- 引入Druid连接池 -->
<dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>druid-spring-boot-starter</artifactId>
    <version>1.1.23</version>
</dependency>
 
<!-- MyBatis与SpringBoot整合依赖 -->
<dependency>
    <groupId>org.mybatis.spring.boot</groupId>
    <artifactId>mybatis-spring-boot-starter</artifactId>
    <version>2.1.3</version>
</dependency>
 
<!-- mysql的JDBC数据库驱动 -->
<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
    <version>8.0.20</version>
</dependency>
 
<!-- 引入Thymeleaf模板引擎 -->
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-thymeleaf</artifactId>
</dependency>

-- 判断数据表是否存在，存在则删除
DROP TABLE IF EXISTS tb_user;
 
-- 创建“用户信息”数据表
CREATE TABLE IF NOT EXISTS tb_user
( 
	user_id INT AUTO_INCREMENT PRIMARY KEY COMMENT '用户编号',
	user_name VARCHAR(50) NOT NULL COMMENT '用户姓名',
	age INT DEFAULT(0) NOT NULL COMMENT '年龄',
	blog_url VARCHAR(50) NOT NULL COMMENT '博客地址',
	blog_remark VARCHAR(50) COMMENT '博客信息'
) COMMENT = '用户信息表';
 
-- 添加数据
INSERT INTO tb_user(user_name,age,blog_url,blog_remark) VALUES('pan_junbiao的博客',32,'https://blog.csdn.net/pan_junbiao','您好，欢迎访问 pan_junbiao的博客');

#Spring配置
spring:
  #使用Thymeleaf模板引擎
  thymeleaf:
    mode: HTML5
    encoding: UTF-8
    cache: false  #使用Thymeleaf模板引擎，关闭缓存
    servlet:
      content-type: text/html
  #JDBC配置
  datasource:
    url: jdbc:mysql://localhost:3306/db_admin?useSSL=false&amp
    username: root
    passWord: 123456
    driver-class-name: com.mysql.cj.jdbc.Driver
    type: com.alibaba.druid.pool.DruidDataSource
    #Druid连接池配置
    druid:
      initial-size: 5 #初始化时建立物理连接的个数
      max-active: 30 #最大连接池数量
      min-idle: 5 # 最小连接池数量
      druid.max-wait: 60000 #获取连接时最大等待时间，单位毫秒
      time-between-eviction-runs-millis: 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
      min-evictable-idle-time-millis: 300000 #连接保持空闲而不被驱逐的最小时间
      validation-query: select 'x' #用来检测连接是否有效的sql 必须是一个查询语句：mysql中为 select 'x' oracle中为 select 1 from dual
      test-while-idle: true #建议配置为true，不影响性能，并且保证安全性。申请连接的时候检测，如果空闲时间大于timeBetweenEvictionRunsMillis，执行validationQuery检测连接是否有效。
      test-on-borrow: false #申请连接时会执行validationQuery检测连接是否有效,开启会降低性能,默认为true
      test-on-return: false #归还连接时会执行validationQuery检测连接是否有效,开启会降低性能,默认为true
      pool-prepared-statements: true #是否缓存preparedStatement,mysql5.5+建议开启
      max-pool-prepared-statement-per-connection-size: 50 #要启用PSCache，必须配置大于0，当大于0时，poolPreparedStatements自动触发修改为true。
      filters: stat,wall #配置监控统计拦截的filters，去掉后监控界面sql无法统计
      connection-properties: druid.stat.mergeSql=true;druid.stat.slowSqlMillis=500 #通过connectProperties属性来打开mergeSql功能；慢SQL记录
      use-global-data-source-stat: true #合并多个DruidDataSource的监控数据
      #StatViewServlet配置
      stat-view-servlet.enabled: true #是否启用StatViewServlet（监控页面）默认值为false
      stat-view-servlet.login-username: admin #设置访问druid监控页的账号,默认没有
      stat-view-servlet.login-password: admin #设置访问druid监控页的密码,默认没有
 
#MyBatis配置
mybatis:
  type-aliases-package: com.pjb.entity #别名定义
  configuration:
    log-impl: org.apache.ibatis.logging.stdout.StdOutImpl #指定 MyBatis 所用日志的具体实现，未指定时将自动查找
    map-underscore-to-camel-case: true #开启自动驼峰命名规则（camel case）映射
    lazy-loading-enabled: true #开启延时加载开关
    aggressive-lazy-loading: false #将积极加载改为消极加载（即按需加载）,默认值就是false
    #lazy-load-trigger-methods: "" #阻挡不相干的操作触发，实现懒加载
    cache-enabled: true #打开全局缓存开关（二级环境），默认值就是true

package com.pjb.entity;
 
import java.io.Serializable;
 

public class UserInfo
{
    private int userId; //用户编号
    private String userName; //用户姓名
    private int age; //年龄
    private String blogUrl; //博客地址
    private String blogRemark; //博客信息
 
    //省略getter与setter方法...
}

package com.pjb.service;
 
import com.pjb.entity.UserInfo;
 

public interface UserService
{
    
    public UserInfo getUserById(int userId);
 
    
    public UserInfo insertUser(UserInfo userInfo);
 
    
    public UserInfo updateUser(UserInfo userInfo);
 
    
    public int deleteUser(int userId);
}

package com.pjb.service;
 
import com.pjb.entity.UserInfo;
 

public interface UserService
{
    
    public UserInfo getUserById(int userId);
 
    
    public UserInfo insertUser(UserInfo userInfo);
 
    
    public UserInfo updateUser(UserInfo userInfo);
 
    
    public int deleteUser(int userId);
}

package com.pjb.service.impl;
 
import com.pjb.entity.UserInfo;
import com.pjb.mapper.UserMapper;
import com.pjb.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;
 

@Service
@Transactional
public class UserServiceImpl implements UserService
{
    @Autowired
    private UserMapper userMapper;
 
    
    @Override
    public UserInfo getUserById(int userId)
    {
        return userMapper.getUserById(userId);
    }
 
    
    @Override
    public UserInfo insertUser(UserInfo userInfo)
    {
        userMapper.insertUser(userInfo);
        return userInfo;
    }
 
    
    @Override
    public UserInfo updateUser(UserInfo userInfo)
    {
        userMapper.updateUser(userInfo);
        return userInfo;
    }
 
    
    @Override
    public int deleteUser(int userId)
    {
        return userMapper.deleteUser(userId);
    }
}

package com.pjb.controller;
 
import com.pjb.entity.UserInfo;
import com.pjb.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.WEB.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.servlet.ModelAndView;
 

@Controller
@RequestMapping("/user")
public class UserController
{
    @Autowired
    private UserService userService;
 
    
    @RequestMapping("getUserById")
    public ModelAndView getUserById(int userId)
    {
        //根据用户ID，获取用户信息
        UserInfo userInfo = userService.getUserById(userId);
 
        if(userInfo==null)
        {
            userInfo = new UserInfo();
        }
 
        //返回结果
        ModelAndView modelAndView = new ModelAndView();
        modelAndView.addObject("userInfo",userInfo);
        modelAndView.setViewName("/user-info.html");
        return modelAndView;
    }
 
    
    @ResponseBody
    @RequestMapping("insertUser")
    public boolean insertUser()
    {
        //创建新用户
        UserInfo userInfo = new UserInfo();
        userInfo.setUserName("pan_junbiao的博客");
        userInfo.setAge(32);
        userInfo.setBlogUrl("Https://blog.csdn.net/pan_junbiao");
        userInfo.setBlogRemark("您好，欢迎访问 pan_junbiao的博客");
 
        //执行新增方法
        userService.insertUser(userInfo);
 
        //返回结果
        return userInfo.getUserId() > 0 ? true : false;
    }
 
    
    @ResponseBody
    @RequestMapping("updateUser")
    public boolean updateUser(int userId)
    {
        UserInfo userInfo = new UserInfo();
        userInfo.setUserId(userId);
        userInfo.setUserName("pan_junbiao的博客_02");
        userInfo.setAge(35);
        userInfo.setBlogUrl("https://blog.csdn.net/pan_junbiao");
        userInfo.setBlogRemark("您好，欢迎访问 pan_junbiao的博客");
 
        //执行修改方法
        userService.updateUser(userInfo);
 
        //返回结果
        return true;
    }
 
    
    @ResponseBody
    @RequestMapping("deleteUser")
    public boolean deleteUser(int userId)
    {
        //执行新增方法
        int result = userService.deleteUser(userId);
 
        //返回结果
        return result > 0 ? true : false;
    }
}

<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.thymeleaf.org">
<head>
    <meta charset="UTF-8">
    <title>用户信息</title>
    <meta name="author" content="pan_junbiao的博客">
    <style>
        table { border-collapse: collapse; margin-bottom: 10px}
        table,table tr th, table tr td { border:1px solid #000000; padding: 5px 10px;}
    </style>
</head>
<body>
<div align="center">
    <table>
        <caption>用户信息</caption>
        <tr>
            <th>用户ID：</th>
            <td th:text="${userInfo.userId}"></td>
        </tr>
        <tr>
            <th>用户名称：</th>
            <td th:text="${userInfo.userName}"></td>
        </tr>
        <tr>
            <th>年龄：</th>
            <td th:text="${userInfo.age}"></td>
        </tr>
        <tr>
            <th>博客地址：</th>
            <td th:text="${userInfo.blogUrl}"></td>
        </tr>
        <tr>
            <th>备注信息：</th>
            <td th:text="${userInfo.blogRemark}"></td>
        </tr>
    </table>
</div>
</body>
</html>