使用前提：导包

方式1：

public class DbcpTest {
    private static String url = "jdbc:mysql://localhost:3306/employee_db";
    private static String user = "root";
    private static String password = "221121";
    private static String driverClass = "com.mysql.jdbc.Driver"; 
    
    static PreparedStatement st = null; 
    static ResultSet rs = null;
    public static void main(String[] args) throws SQLException {
        //创建连接池对象
        BasicDataSource bds = new BasicDataSource();
        
        //设置连接参数
        bds.setUrl(url);
        bds.setUsername(user);
        bds.setPassword(password);
        bds.setDriverClassName(driverClass);
        
        //设置连接池参数
        bds.setInitialSize(5);//初始化连接个数
        bds.setMaxActive(10);//最大连接个数
        bds.setMaxWait(3000);//当超过最大连接数的等候时间
        
        try{
            Connection conn = bds.getConnection();
            st = conn.prepareStatement("select * from employee");
            rs = st.executeQuery();
            while(rs.next()){
                int id = rs.getInt(1);
                String name = rs.getNString("name");
                System.out.println(id+":"+name);
            }
                
        }catch (Exception e){
            e.printStackTrace();
        } finally{
            bds.close();//把连接对象放回连接池R
        }
    }

}

方式2：
配置文件

public class DbcpTest2 {
    
    static PreparedStatement st = null; 
    static ResultSet rs = null;
    public static void main(String[] args) throws SQLException {
        try {
            //1)使用工厂类来创建dbcp连接池对象（读取配置文件方式）
            Properties prop = new Properties();
            //使用类路径读取配置文件
            InputStream in = DbcpTest2.class.getResourceAsStream("/jdbc.properties");
            //加载配置文件
            prop.load(in);

            BasicDataSource bds = (BasicDataSource)BasicDataSourceFactory.createDataSource(prop);
            /**
             * 读取jdbc.properties文件内容
             *   dbcp可以自动识别每个配置信息，但是约定前提： 配置文件的key名称和设置方法的名称保持一致！！！
             */
            
            Connection conn = bds.getConnection();
            st = conn.prepareStatement("select * from employee");
            rs = st.executeQuery();
            while(rs.next()){
                int id = rs.getInt(1);
                String name = rs.getNString("name");
                System.out.println(id+":"+name);
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

}