关于druid连接池的使用详解

DruidDataSource dds = new DruidDataSource();
    
        try {
            dds.setUrl("jdbc:mysql://localhost:3306/");
            dds.setUsername("root");
            dds.setPassword("admin");
            dds.setDriverClassName("com.mysql.cj.jdbc.Driver");
            System.out.println(dds.getConnection());
        } catch (SQLException e) {
            e.printStackTrace();
        }

DruidDataSource dds = new DruidDataSource();
        Properties p = new Properties();
        //加载提前写好的配置文件
        InputStream is = Thread.currentThread().getContextClassLoader().getResourceAsStream("db.properties");
        try {
            p.load(is);
            //druid加载文件内容
            dds.setConnectProperties(p);
            System.out.println(dds.getConnection());
        } catch (IOException e) {
            e.printStackTrace();
        } catch (SQLException e) {
            e.printStackTrace();
        }

#必须按这个配置名填写druid.
druid.url=jdbc:mysql://localhost:3306/db1
druid.username=root
druid.password=admin
druid.driverClassName=com.mysql.cj.jdbc.Driver
#初始化创建连接数
druid.initialSize=2
#最大连接数
druid.maxActive=8
#启用数据监控监控
druid.filters=stat config

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xmlns="http://xmlns.jcp.org/xml/ns/javaee"
         xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee
http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd"
         version="4.0">
<!-- 过滤器 -->
    <filter>
        <filter-name>DruidWebStatFilter</filter-name>
        <filter-class>com.alibaba.druid.support.http.WebStatFilter</filter-class>
        <init-param>
            <param-name>exclusions</param-name>
            <param-value>*.js,*.gif,*.jpg,*.png,*.css,*.ico,/druid/*</param-value>
        </init-param>
    </filter>
    <filter-mapping>
        <filter-name>DruidWebStatFilter</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>
    <servlet>
        <servlet-name>DruidStatView</servlet-name>
        <servlet-class>com.alibaba.druid.support.http.StatViewServlet</servlet-class>
        <init-param>
            <!-- 允许清空统计数据 -->
            <param-name>resetEnable</param-name>
            <param-value>true</param-value>
        </init-param>
        <init-param>
            <!-- 用户名 -->
            <param-name>loginUsername</param-name>
            <param-value>admin</param-value>
        </init-param>
        <init-param>
            <!-- 密码 -->
            <param-name>loginPassword</param-name>
            <param-value>123</param-value>
        </init-param>
    </servlet>
    <servlet-mapping>
        <servlet-name>DruidStatView</servlet-name>
        <url-pattern>/druid/*</url-pattern>
    </servlet-mapping>


</web-app>