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Python 全系列/第十八阶段:数据分析-数据可视化/pyecharts(旧) 23926楼

无法初始化类com.bjsxt.JdbcUtil文件。

image.png

工具类代码:

package com.bjsxt;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.ResourceBundle;

/**
 * jdbc工具类
 */
public class JdbcUtil {
    private static String driver;
    private static String jdbcUrl;
    private static String username;
    private static String userpassword;
    static {
        //读取Properties文件
        ResourceBundle bundle = ResourceBundle.getBundle("jdbc.properties");
        driver = bundle.getString(driver);
        jdbcUrl = bundle.getString(jdbcUrl);
        username = bundle.getString(username);
        userpassword = bundle.getString(userpassword);
        try {
            Class.forName(driver);
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        }
    }
    //获取Connection对象
    public static Connection getConnection(){
        Connection conn = null;
        try {
            conn = DriverManager.getConnection(jdbcUrl,username,userpassword);
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return conn;
    }
    //关闭Statement
    public static void closeStatement(Statement state){
        try {
             if(state != null){
                state.close();
                }
             } catch (SQLException throwables) {
                throwables.printStackTrace();
             }

    }
    //关闭Connection
    public static void closeConnection(Connection conn){
        try {
            if(conn != null){
                conn.close();
            }
        }catch (SQLException throwables){
            throwables.printStackTrace();
        }
    }
    //关闭资源
    public static void closeResource(Statement state,Connection conn){
        closeStatement(state);
        closeConnection(conn);
    }
}

propenties:

driver=com.mysql.jdbc.Driver
jdbcUrl=jdbc:mysql://localhost:3306/bjsxt?useUnicode=true&characterEncoding=utf-8
username=root
userpassword=root

测试:

package com.bjsxt;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.ResourceBundle;

public class JdbcTest {
    //向Departments表中添加一条数据
    public void insertDepartments(String department_name,int location_id){
        Connection conn = null;
        Statement state = null;
        //驱动注册
        try {
            conn = JdbcUtil.getConnection();
            String sql="insert into departments values(default,'"+department_name+"',"+location_id+")";
            state = conn.createStatement();
            int flag = state.executeUpdate(sql);
            System.out.println(flag);
        } catch (Exception e) {
            e.printStackTrace();
        }finally{
            JdbcUtil.closeResource(state,conn);
        }
    }
    //更新departments表中的department_id为6的数据,将部门名称修改为教学部,location_id修改为6
    public void updateDepartments(String department_name,int location_id,int department_id){
        Connection conn = null;
        Statement state = null;
        try {
            conn = JdbcUtil.getConnection();
            state = conn.createStatement();
            String sql = "update departments d set d.department_name='"+department_name+"',d.location_id="+location_id+" where d.department_id="+department_id;
            int flag = state.executeUpdate(sql);
            System.out.println(flag);

        }catch (Exception e){
            e.printStackTrace();
        }finally {
            JdbcUtil.closeResource(state,conn);
        }
    }
    public static void main(String[] args) {
        JdbcTest test = new JdbcTest();
        test.insertDepartments("教学部",9);
        //test.updateDepartments("研发部",8,6);
    }
}

问题应该在properties文件读取不到,绝对路径试过了,一模一样的报错,不读取properties文件没有问题。请老师讲解

JAVA 全系列/第三阶段:数据库编程/JDBC技术(旧) 23929楼
JAVA 全系列/(旧的隐藏)第二十一阶段:百战商城项目(Spring Cloud最新架构)/百战商城项目 23930楼

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>利用定位知识点</title>
    <style>
        * {
            /*p默认有16px的上下外边距*/
            margin: 0px;
        }
    .box{
        position:relative;
        width: 100%;
        height: 1155px;
    }
   .box img{
       width:100%;
   }
        .box1,.box2{
           width:303px;
           height:375px;
           background-color: red;
           position:absolute;
           top: 10px;
           left: 10px;
           right: 10px;
           /*position:static;使用静态定位,就相对浏览页面*/
       }


        a{
            text-decoration:none;
        }
        .box1,.box2{
            position:relative;
        }
        .text1,.text2{
            width:303px;
            height:88px;
            position:absolute;
            left:0px;
            bottom:20px;
            text-align:center;
        }
        .name1{
            color: #fff;
            font-size: 21px;
            font-weight: 700;
        }
        .desc1{
            color:#fff;
            font-size:14px;
        }
        .price1{
            color: #ebce6b;
            font-size: 24px;
            font-weight: 700;
        }
        .box2{
            background-color: whitesmoke;

        }

        .name2{
            color: #333;
            font-size: 16px;
        }
        .desc2{
            color:#999;
            font-size: 14px;
        }
        .price2{
            color: #ebce6b;
            font-size: 24px;
            font-weight: 700;
        }
        .box2 span{
            color:#cc0000;
            font-size: 14px;
        }
        .box2 .number{
            color:#cc0000;
            font-size: 22px;
        }
        s{
            color:gray;
            font-size: 14px;
        }
    </style>
</head>
<body>
<div class="box">
    <div class="box1">
        <a href="#">
            <img src="images/1.jpg" alt="">
            <div class="text1">
                <p class="name1">魅族 EP3C 耳机</p>
                <p class="desc1">【限时特惠99元】</p>
                <p class="price1">¥129</p>
            </div>
        </a>
    </div>
    <div class=" box2">
        <a href="#">
            <img src="images/2.png" alt="">
            <div class="text2 ">
                <p class="name2">魅族 POP Pro 主动降噪耳机</p>
                <p class="desc2">三重混合主动降噪技术 | 三麦克风智能通话降噪</p>
                <p class="price2"><span>¥</span><span class="number">499</span></p>
            </div>
        </a>
    </div>
    <div class=" box2">
        <a href="#">
            <img src="images/3.png" alt="">
            <div class="text2 ">
                <p class="name2">魅族 POP2s 真无线耳机</p>
                <p class="desc2">【限时6期免息】好声音标杆 | Flyme 妙连</p>
                <p class="price2"><span>¥</span><span class="number">299</span></p>
            </div>
        </a>
    </div>
    <div class=" box2">
        <a href="#">
            <img src="images/4.png" alt="">
            <div class="text2 ">
                <p class="name2">魅族 HIFI 解码耳放</p>
                <p class="desc2">【年货节特惠价149元】</p>
                <p class="price2"><span>¥</span><span class="number">169</span></p>
            </div>
        </a>
    </div>
    <div class=" box2">
        <a href="#">
            <img src="images/5.jpg" alt="">
            <div class="text2 ">
                <p class="name1">魅族 HD60 头戴式蓝牙耳机</p>
                <p class="desc1">【年货节特惠价349元+12期免息】</p>
                <p class="price1">¥499</p>
            </div>
        </a>
    </div>
    <div class=" box2">
        <a href="#">
            <img src="images/6.png" alt="">
            <div class="text2 ">
                <p class="name2">魅族 HD60 降噪耳机</p>
                <p class="desc2">【年货节特惠价799元+12期免息】</p>
                <p class="price2"><span>¥</span><span class="number">1099</span></p>
            </div>
        </a>
    </div>
    <div class=" box2">
        <a href="#">
            <img src="images/7.png" alt="">
            <div class="text2 ">
                <p class="name2">魅族 EP63NC 无线降噪耳机</p>
                <p class="desc2">【年货节特惠价249元+6期免息】</p>
                <p class="price2"><span>¥</span><span class="number">249</span><s>¥499</s></p>
            </div>
        </a>
    </div>
    <div class=" box2">
        <a href="#">
            <img src="images/8.png" alt="">
            <div class="text2 ">
                <p class="name2">魅族 POP Pro 主动降噪耳机</p>
                <p class="desc2">【年货节特惠价149元】</p>
                <p class="price2"><span>¥</span><span class="number">149</span><s>¥169</s></p>
            </div>
        </a>
    </div>
</div>
</body>
</html>

这个我用定位的知识,父元素用了相对定位,8个div子元素用绝对定位,但效果图没有实现,水平显示。我想实现以下效果图。

blob.png

WEB前端全系列/第一阶段:HTML5+CSS3模块/CSS常用属性 23931楼

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
        *{
            margin: 0;
            padding: 0;
        }
        a{
            text-decoration: none;
        }
        .box,.box1{
            width: 303px;
            height: 375px;
            background-color: red;
            position: relative;
        }
        .box1{
            float:left;
        }
         img{
            width: 100%;
        }
        .text{
            width: 100%;
            height: 88px;
            /*相对于已经定位的父元素定位*/
            position: absolute;
            left: 0;
            bottom: 20px;
            text-align: center;

        }
        .name{
            color: #fff;
            font-size: 21px;
            font-weight: 700;
        }
        .desc{
            color: #fff;
            font-size: 14px;
        }
        .price{
            color: #ebce6b;
            font-size: 24px;
            font-weight: 700;
        }
    </style>
</head>
<body>
<div class="box">
    <a href="#">
        <img src="images/370ad36f-425c-453a-b406-ccb2a0dffeec.jpg" alt="">
        <div class="text">
            <p class="name">MEIZU UR 高端定制耳机 预约</p>
            <p class="desc">【预约专用】私人定制,为你而声</p>
            <p class="price">¥200</p>
        </div>
    </a>
</div>
<div class="box1">
    <a href="#">
        <img src="images/370ad36f-425c-453a-b406-ccb2a0dffeec.jpg" alt="">
        <div class="text">
            <p class="name">MEIZU UR 高端定制耳机 预约</p>
            <p class="desc">【预约专用】私人定制,为你而声</p>
            <p class="price">¥200</p>
        </div>
    </a>
</div>
</body>
</html>

我已经在box1处加了float:left;效果图为什么没有实现块级元素水平显示

WEB前端全系列/第一阶段:HTML5+CSS3模块/CSS常用属性 23932楼

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
        * {
            /*p默认有16px的上下外边距*/
            margin: 0px;
        }
        .box{
            width:1260px;
            height:780px;
            position:relative;
        }
        /* 合并选择器*/
        .box1,.box2 {
            width:303px;
            height:375px;
            background-color: red;
            position:relative;
            float: left;
            margin:12px 0px 0px 12px;
            /*position:static;使用静态定位,就相对浏览页面*/
        }
         img{
            width:100%;
        }
        .text1{
            width:303px;
            height:88px;
            position:absolute;
            left:0px;
            bottom:20px;
            text-align:center;
        }
        .name1{
            color: #fff;
            font-size: 21px;
            font-weight: 700;
        }
        .desc1{
            color:#fff;
            font-size:14px;
        }
        .price1{
            color: #ebce6b;
            font-size: 24px;
            font-weight: 700;
        }
        .box2{
            background-color: whitesmoke;

        }
        .box2 img{
            width:100%;
        }
        .text2{
            width:303px;
            height:88px;
            position:absolute;
            left:0px;
            bottom:20px;
            text-align:center;
        }
        .name2{
            color: #333;
            font-size: 16px;
        }
        .desc2{
            color:#999;
            font-size: 14px;
        }
        .price2{
            color: #ebce6b;
            font-size: 24px;
            font-weight: 700;
        }
        .box2 span{
            color:#cc0000;
            font-size: 14px;
        }
        .box2 .number{
            color:#cc0000;
            font-size: 22px;
        }
        s{
            color:gray;
            font-size: 14px;
        }
    </style>
</head>
<body>
<div class="box">
    <div class="box1">

        <img src="images/1.jpg" alt="">
        <div class="text1">
            <p class="name1">魅族 EP3C 耳机</p>
            <p class="desc1">【限时特惠99元】</p>
            <p class="price1">¥129</p>
        </div>
    </a>
</div>
    <div class=" box2">

        <img src="images/2.png" alt="">
        <div class="text2 ">
            <p class="name2">魅族 POP Pro 主动降噪耳机</p>
            <p class="desc2">三重混合主动降噪技术 | 三麦克风智能通话降噪</p>
            <p class="price2"><span>¥</span><span class="number">499</span></p>
        </div>
        </a>
    </div>
    <div class=" box2">

        <img src="images/3.png" alt="">
        <div class="text2 ">
            <p class="name2">魅族 POP2s 真无线耳机</p>
            <p class="desc2">【限时6期免息】好声音标杆 | Flyme 妙连</p>
            <p class="price2"><span>¥</span><span class="number">299</span></p>
        </div>
        </a>
    </div>
    <div class=" box2">

        <img src="images/4.png" alt="">
        <div class="text2 ">
            <p class="name2">魅族 HIFI 解码耳放</p>
            <p class="desc2">【年货节特惠价149元】</p>
            <p class="price2"><span>¥</span><span class="number">169</span></p>
        </div>
        </a>
    </div>
    <div class=" box2">

        <img src="images/5.jpg" alt="">
        <div class="text2 ">
            <p class="name1">魅族 HD60 头戴式蓝牙耳机</p>
            <p class="desc1">【年货节特惠价349元+12期免息】</p>
            <p class="price1">¥499</p>
        </div>
        </a>
    </div>
    <div class=" box2">

        <img src="images/6.png" alt="">
        <div class="text2 ">
            <p class="name2">魅族 HD60 降噪耳机</p>
            <p class="desc2">【年货节特惠价799元+12期免息】</p>
            <p class="price2"><span>¥</span><span class="number">1099</span></p>
        </div>
        </a>
    </div>
    <div class=" box2">

        <img src="images/7.png" alt="">
        <div class="text2 ">
            <p class="name2">魅族 EP63NC 无线降噪耳机</p>
            <p class="desc2">【年货节特惠价249元+6期免息】</p>
            <p class="price2"><span>¥</span><span class="number">249</span><s>¥499</s></p>
        </div>
        </a>
    </div>
    <div class=" box2">

        <img src="images/8.png" alt="">
        <div class="text2 ">
            <p class="name2">魅族 POP Pro 主动降噪耳机</p>
            <p class="desc2">【年货节特惠价149元】</p>
            <p class="price2"><span>¥</span><span class="number">149</span><s>¥169</s></p>
        </div>
        </a>
    </div>
</div>
</body>
</html>

老师,我想实现图片居中,该怎么弄,现在的效果图全部靠左,我想两边空白地方一样多

blob.png

右边红色的地方太多了,如何左右均匀分布



WEB前端全系列/第一阶段:HTML5+CSS3模块/CSS常用属性 23933楼
Python 全系列/第十二阶段:Python_Django3框架/Django初级 23938楼
Python 全系列/第十阶段:Flask百战电商后台项目/Flask百战电商后台项目 23939楼

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