PHP 21 文件上传（续）与分页操作（0731fri）

主要内容：

文件上传的异常处理
将文件从临时目录移动到正式目录
批量上传文件
分页操作

1. 文件上传的异常处理

<?php
error_reporting(E_ALL);
// $_FILES: 文件上传变量,超全局的变量数组, 保存着所有与文件上传的相关信息
printf('<pre>%s</pre>', print_r($_FILES, true));
// 自定义文件上传的异常处理类
class UploadException extends Exception
{
    public function __toString()
    {
        return <<< UPLOAD
        <table>
            <tr>
                <td>编号</td>
                <td>信息</td>
                <td>文件</td>
                <td>行号</td>
            </tr>
            <tr>
                <td>$this->code</td>
                <td>$this->message</td>
                <td>$this->file</td>
                <td>$this->line</td>
            </tr>
        </table>
        <style>
table {border-collapse: collapse;border:1px solid black;text-align: center;}
td {border:1px solid black;padding: 5px;}
tr:first-of-type {background-color:#eee;}
tr:last-of-type td {color: red;}
</style>
UPLOAD;
    }
}
try {
// 对错误编码的判断
$errorCode = $_FILES['my_pic']['error'] ?? null;
// 使用系统常量进行判断
if ($errorCode > UPLOAD_ERR_OK) { //也就是说大于0。
    switch ($errorCode) {
        case UPLOAD_ERR_INI_SIZE:
            throw new UploadException('上传的文件超过了 php.ini 中 upload_max_filesize 选项限制的值',1);
        break;
        case UPLOAD_ERR_FORM_SIZE:
            throw new UploadException('上传文件的大小超过了 HTML 表单中 MAX_FILE_SIZE 选项指定的值', 2);
        break;
        case UPLOAD_ERR_PARTIAL:
            throw new UploadException('文件只有部分被上传', 3);
            break;
        case UPLOAD_ERR_NO_FILE:
            throw new UploadException('没有文件被上传', 4);
            break;
        case UPLOAD_ERR_NO_TMP_DIR:
            throw new UploadException('找不到临时文件夹', 5);
            break;
        case UPLOAD_ERR_CANT_WRITE:
            throw new UploadException('文件写入失败', 6);
            break;
        default:
            // 测试时建议关掉default: 避免误报影响
            throw new UploadException('未知类型错误', 7);
    }
}
// 判断文件类型是否正确?
$fileType = $_FILES['my_pic']['type'] ?? null;
$type = strstr($fileType, '/', true); // "image"
if (!is_null($fileType)) {
    if ($type !== 'image') throw new UploadException('文件类型错误', 8);
}
// 判断上传方式是否正确?
// 临时文件名
$tmplFileName = $_FILES['my_pic']['tmp_name']  ?? null;
// 首先临时文件是存在的,并且必须是通过POST上传的
if (!($tmplFileName && is_uploaded_file($tmplFileName))) throw new UploadException('上传类型错误', 9);
} catch (UploadException $e) {
    echo $e;
}
?>
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>文件上传的异常处理</title>
</head>
<body>
    <form action="" method="POST" enctype="multipart/form-data">
        <fieldset>
            <legend>单文件上传</legend>
            <!-- 隐藏域设置上传文件大小,必须写到input:file之前 -->
            <input type="hidden" name="MAX_FILE_SIZE" value="38000">
            <input type="file" name="my_pic" id="">
            <button>上传</button>
        </fieldset>
    </form>
</body>
</html>

<?php
error_reporting(E_ALL);
// $_FILES: 文件上传变量,超全局的变量数组, 保存着所有与文件上传的相关信息
printf('<pre>%s</pre>', print_r($_FILES, true));
// 自定义文件上传的异常处理类
class UploadException extends Exception
{
    public function __toString()
    {
        return <<< UPLOAD
        <table>
            <tr>
                <td>编号</td>
                <td>信息</td>
                <td>文件</td>
                <td>行号</td>
            </tr>
            <tr>
                <td>$this->code</td>
                <td>$this->message</td>
                <td>$this->file</td>
                <td>$this->line</td>
            </tr>
        </table>
        <style>
table {border-collapse: collapse;border:1px solid black;text-align: center;}
td {border:1px solid black;padding: 5px;}
tr:first-of-type {background-color:#eee;}
tr:last-of-type td {color: red;}
</style>
UPLOAD;
    }
}
try {
// 对错误编码的判断
$errorCode = $_FILES['my_pic']['error'] ?? null;
// 使用系统常量进行判断
if ($errorCode > UPLOAD_ERR_OK) {
    switch ($errorCode) {
        case UPLOAD_ERR_INI_SIZE:
            throw new UploadException('上传的文件超过了 php.ini 中 upload_max_filesize 选项限制的值',1);
        break;
        case UPLOAD_ERR_FORM_SIZE:
            throw new UploadException('上传文件的大小超过了 HTML 表单中 MAX_FILE_SIZE 选项指定的值', 2);
        break;
        case UPLOAD_ERR_PARTIAL:
            throw new UploadException('文件只有部分被上传', 3);
            break;
        case UPLOAD_ERR_NO_FILE:
            throw new UploadException('没有文件被上传', 4);
            break;
        case UPLOAD_ERR_NO_TMP_DIR:
            throw new UploadException('找不到临时文件夹', 5);
            break;
        case UPLOAD_ERR_CANT_WRITE:
            throw new UploadException('文件写入失败', 6);
            break;
        default:
            // 测试时建议关掉default: 避免误报影响
            throw new UploadException('未知类型错误', 7);
    }
}
// 判断文件类型是否正确?
$fileType = $_FILES['my_pic']['type'] ?? null;
$type = strstr($fileType, '/', true); // "image"
if (!is_null($fileType)) {
    if ($type !== 'image') throw new UploadException('文件类型错误', 8);
}
// 判断上传方式是否正确?
// 临时文件名
$tmplFileName = $_FILES['my_pic']['tmp_name']  ?? null;
// 1. 首先临时文件是存在的,并且必须是通过POST上传的
if ($tmplFileName && is_uploaded_file($tmplFileName)) {
// 2. 将文件从临时目录移动到目标目录中: uploads/
    // move_uploaded_file(临时文件, 目标文件名)
    // 原始文件名
    $originalFileName =  $_FILES['my_pic']['name'] ?? null;
    // echo strstr($originalFileName, '.'); //显示扩展名
    // 目标文件名，用时间加盐，然后加载一个随机数，再用md5生成加密字符串作为文件名。
    // 这样同一文件多次上传也不会覆盖，而是生成新的。
    $destFileName = 'uploads/' . md5(time(). mt_rand(1,1000))  .strstr($originalFileName, '.');
    if (move_uploaded_file($tmplFileName, $destFileName)) {
        echo '<p>'. $_FILES['my_pic']['name'].': 上传成功</p>';
        // 预览图片
        echo "<img src='{$destFileName}' width='200'>";
    }
}
} catch (UploadException $e) {
    echo $e;
}
?>
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>将文件从临时目录移动到正式目录中</title>
</head>
<body>
    <form action="" method="POST" enctype="multipart/form-data">
        <fieldset>
            <legend>单文件上传</legend>
            <!-- 隐藏域设置上传文件大小,必须写到input:file之前 -->
            <!-- <input type="hidden" name="MAX_FILE_SIZE" value="38000"> -->
            <input type="file" name="my_pic" id="">
            <button>上传</button>
        </fieldset>
    </form>
</body>
</html>

3. 批量上传文件

<?php
error_reporting(E_ALL);
printf('<pre>%s</pre>', print_r($_FILES, true));
// 异常处理, 错误处理,这里省略... 
foreach ($_FILES as $file) {
    // print_r($file);
    // 判断 $file['error'] 是否为0,如果为0表示上传成功
    if ($file['error'] === 0) {
        $destFileName = 'uploads/' . md5(time(). mt_rand(1,1000))  .strstr($file['name'], '.');
        if (move_uploaded_file($file['tmp_name'], $destFileName)) {
            echo '<p>'. $file['name'].': 上传成功</p>';
        // 预览图片
        echo "<img src='{$destFileName}' width='200'>";
        }
    }
}
?>
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>多文件上传</title>
</head>
<body>
    <form action="" method="POST" enctype="multipart/form-data">
        <fieldset>
            <legend>批量上传文件</legend>
            <!-- 隐藏域设置上传文件大小,必须写到input:file之前 -->
            <!-- <input type="hidden" name="MAX_FILE_SIZE" value="38000"> -->
            <input type="file" name="my_pic1" id="">
            <input type="file" name="my_pic2" id="">
            <input type="file" name="my_pic3" id="">
            <button>上传</button>
        </fieldset>
    </form>
</body>
</html>

4. 分页操作

4-1. 基本知识: 分页原理

4-1-1. 术语

记录索引: 记录在表中的位置,从 0 开始编号(与主键的值无关)
偏移量: 每页显示的索引距离起始索引 0 的相对位置
显示数量: 每页的显示记录的条数

SELECT * FROM `users` 每页的数量 显示的偏移量
-- 每页的数量: LIMIT n
-- 显示的偏移量: 从哪个索引开始显示  OFFSET m
# 从第1页开始显示5条
SELECT * FROM `users` LIMIT 5 OFFSET 0;
-- (1-1)*5 = 0
# 第二页,从索引5开始显示
SELECT * FROM `users` LIMIT 5 OFFSET 5;
-- (2-1)*5 = 5
# 第3页,从索引10开始,即偏移量为10, 偏移量从第一条记录的索引开始计数
SELECT * FROM `users` LIMIT 5 OFFSET 10;
-- (3-1)*5 = 10

分页的时候,一定会提供当前的页数,还有就是每一页的显示的记录数量
而偏移量是动态变量的变量,随页数不同而发生变化

4-1-2. 计算偏移量

偏移量 = (页码 -1) * 每页的显示数量
offset = (page - 1) * num

4-2. 操作

先建立一个connect.php文件

<?php
// 连接数据库
// PDO连接对象
$pdo = new PDO('mysql:host=localhost;dbname=phpedu', 'root', 'root');
// 设置结果默认获取方式: 关联数组
$pdo->setAttribute(PDO::ATTR_DEFAULT_FETCH_MODE, PDO::FETCH_ASSOC);

然后开始操作分页

<?php
// 连接数据库
require 'connect.php';
// 获取分页数据, 一定要知道的二个数据
// 1. 每页显示的数量
$num = 5;
// 2. 当前页码,默认为1
$page = $_GET['p'] ?? 1;
// 3. 计算每一页的第一条记录的显示偏移量（每页展示量）
$offset = ($page - 1) * $num;
// 4. 获取分页数据
// SElECT * FROM `table_name `LIMIT n OFFSET m;
$sql = "SELECT * FROM `users` LIMIT {$num} OFFSET {$offset}";
// 简写
// $sql = "SELECT * FROM `users` LIMIT {$offset}, {$num}";
$users = $pdo->query($sql)->fetchAll();
// print_r($users);
// 计算总页数

分页展示的结果html

<?php require 'demo4.php' ?>
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>数据展示</title>
    <link rel="stylesheet" href="style.css">
</head>
<body>
    <table>
        <caption>用户信息表</caption>
        <thead>
            <tr>
                <td>id</td>
                <td>name</td>
                <td>email</td>
                <td>操作</td>
            </tr>
        </thead>
        <tbody>
            <?php foreach ($users as $user):?>
                <tr>
                     <!-- 短标签来简化变量的显示 -->
                    <td><?=$user['id']?></td>
                    <td><?php echo $user['name'] ?></td>
                    <td><?=$user['email']?></td>
                    <td><button>编辑</button><button>删除</button></td>
                </tr>
            <?php endforeach ?>
        </tbody>
    </table>
</body>
</html>

css文件部分

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  color: #555;
}
body {
  display: flex;
  flex-direction: column;
  align-items: center;
}
/*表格样式*/
table {
  width: 80%;
  border: 1px solid;
  border-collapse: collapse;
  text-align: center;
}
table caption {
  font-size: 1.2rem;
  margin: 10px;
}
table td,
table th {
  border: 1px solid;
  padding: 5px;
}
table tr:hover {
  background-color: #eee;
}
table thead tr:only-of-type {
  background-color: lightblue;
}
table button {
  width: 56px;
  height: 26px;
}
table button:last-of-type {
  color: red;
}
table button {
  cursor: pointer;
  margin: 0 3px;
}
/*分页条样式*/
body > p {
  display: flex;
}
p > a {
  text-decoration: none;
  color: #555;
  border: 1px solid;
  padding: 5px 10px;
  margin: 10px 2px;
}
.active {
  background-color: red;
  color: white;
  border: 1px solid red;
}

5. 作业实战

单文件上传

<?php
/*
1. 实现单文件上传,要求自定义异常类来处理常见错误 
2. 将demo3.php中的文件批量上传中缺失的异常处理, 文件类型处理等操作补齐
附加/选做: 封装一个文件上传类,可同时处理单文件与多文件上传
*/
error_reporting(E_ALL);
printf('<pre>%s</pre>',print_r($_FILES, true));
class UploadEcpt extends Exception
{
    public function __toString()
    //__toString应该是Exception中唯一可以进行访问的功能
    {
        return <<< UPLOAD
        <table>
            <tr>
                <td>编号</td>
                <td>信息</td>
                <td>文件</td>
                <td>line</td>
            </tr>
            <tr>
                <td>$this->code</td>
                <td>$this->message</td>
                <td>$this->file</td>
                <td>$this->line</td>
            </tr>
            <style>
                table {border-collapse:collapse;border:1px solid yellow;
                    text-align:center;}
                td {border: 1px solid black; padding:5px;}
                tr: first-of-type {background-color:#eee;}
                tr: last-of-type td {color:red;}
            </style>
        </table>
        UPLOAD;
    }
}
$errorCode = $_FILES['my_file']['error']?? null;
//下面这块的内容简化到$errorCode中。这个是学老周的方法
$fileType = $_FILES['my_file']['type']?? null;
$type = strstr($fileType, '/', true);
$tmpFileName = $_FILES['my_file']['tmp_name']?? null;
if (!is_null($fileType) && $type !== 'image') $errorCode = 8;
if (!$tmpFileName && is_uploaded_file($tmpFileName)) $errorCode = 9;
try {
    if ($errorCode > 0) {
        switch($errorCode){
            case 1: throw new UploadEcpt("文件超过php.ini限制值",1); break;
            case 2: throw new UploadEcpt("文件超过表单限定值",2);    break;
            case 3: throw new UploadEcpt("文件只有部分被上传",3);    break;
            case 4: throw new UploadEcpt("没有文件被上传",4);       break;
            case 5: throw new UploadEcpt("",5);                    break;
            case 6: throw new UploadEcpt("找不到临时文件夹",6);     break;
            case 7: throw new UploadEcpt("文件写入失败",7);         break; 
            case 8: throw new UploadEcpt("文件类型出错",8);         break;
            case 9: throw new UploadEcpt("上传方式不是POST",9);      break;   
            default:  throw new UploadEcpt("未知类型错误",77);
        }
    }
} catch (UploadEcpt $e){
    echo $e;
}
?>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>文件上传</title>
</head>
<body>
    <form action="" method="POST" enctype="multipart/form-data">
        <fieldset>
            <legend>单文件上传</legend>
            <input type="hidden" name="max_file_siez" value="4000">
            <input type="file" name="my_file" id="">
            <button>上传</button>
        </fieldset>
    </form>
</body>
</html>

多文件上传下的异常报错

<?php
error_reporting(E_ALL);
printf('<pre>%s</pre>', print_r($_FILES, true));
class UploadEcpt extends Exception
{
    public function __toString()
    {
        return <<< UPLOAD
        <table>
            <tr>
                <td>编号</td>
                <td>信息</td>
                <td>文件</td>
                <td>line</td>
            </tr>
            <tr>
                <td>$this->code</td>
                <td>$this->message</td>
                <td>$this->file</td>
                <td>$this->line</td>
            </tr>
            <style>
                table {border-collapse:collapse;border:1px solid yellow;
                    text-align:center;}
                td {border: 1px solid black; padding:5px;}
                tr: first-of-type {background-color:#eee;}
                tr: last-of-type td {color:red;}
            </style>
        </table>
        UPLOAD;
    }
}
try {
    foreach ($_FILES as $FILE) {
        $errorCode = $FILE['error']?? null;
        $fileType = $FILE['type']?? null;
        $type = strstr($fileType, '/', true);
        $tmpFileName = $FILE['tmp_name']?? null;
        if (!is_null($fileType) && $type !== 'image') $errorCode = 8;
        if (!($tmpFileName && is_uploaded_file($tmpFileName))) $errorCode = 9;
        switch($errorCode){
            case 1: throw new UploadEcpt("文件超过php.ini限制值",1);    break;
            case 2: throw new UploadEcpt("文件超过表单限定值",2);       break;
            case 3: throw new UploadEcpt("文件只有部分被上传",3);       break;          
            case 4: throw new UploadEcpt("没有文件被上传",4);           break;
            case 5: throw new UploadEcpt("",5);                        break;
            case 6: throw new UploadEcpt("找不到临时文件夹",6);         break;
            case 7: throw new UploadEcpt("文件写入失败",7);            break;
            case 8: throw new UploadEcpt("文件类型出错",8);            break;
            case 9: throw new UploadEcpt("上传方式不是POST",9);        break;
            case 0:
                $destFileName = 'uploads/' . md5(time(). mt_rand(1,1000))  .strstr($FILE['name'], '.');
                if (move_uploaded_file($FILE['tmp_name'], $destFileName)) {
                echo '<p>'. $FILE['name'].': 上传成功</p>';
                echo "<img src='{$destFileName}' width='200'>";}       
            break;
            default: throw new UploadEcpt("未知类型错误",77);
            }
        // 下面这段按照老周的方式赋值到了$errorCode中(line)。
        // $fileType = $FILE['type']?? null;
        // $type = strstr($fileType, '/', true);
        // if (!is_null($fileType)) {
        //     if ($type !== 'image') throw new UploadEcpt('文件类型出错',8);
        // }
        // $tmpFileName = $FILE['tmp_name']?? null;
        // if (!($tmpFileName && is_uploaded_file($tmpFileName)))
        //     throw new UploadEcpt('上传方式不是POST',9);
}} catch (UploadEcpt $e){
    echo $e;
}
// 这段也放入到了上面的switch中。
// foreach ($_FILES as $file) {
//     // print_r($file);
//     // 判断 $file['error'] 是否为0,如果为0表示上传成功
//     if ($file['error'] === 0) {
//         $destFileName = 'uploads/' . md5(time(). mt_rand(1,1000))  .strstr($file['name'], '.');
//         if (move_uploaded_file($file['tmp_name'], $destFileName)) {
//             echo '<p>'. $file['name'].': 上传成功</p>';
//         // 预览图片
//         echo "<img src='{$destFileName}' width='200'>";
//         }
//     }
// }
?>
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>多文件上传</title>
</head>
<body>
    <form action="" method="POST" enctype="multipart/form-data">
        <fieldset>
            <legend>批量上传文件</legend>
            <input type="hidden" name="MAX_FILE_SIZE" value="3800000">
            <input type="file" name="my_file1" id="">
            <input type="file" name="my_file2" id="">
            <input type="file" name="my_file3" id="">
            <button>上传</button>
        </fieldset>
    </form>
</body>
</html>

分页显示的文件1

<?php
require 'myconnect.php';
$numPerPage = 8;
$pageNum = $_GET['p']?? 1;
$offset = ($pageNum-1) * $numPerPage;
$sql = "SELECT * FROM `shao` LIMIT {$offset}, {$numPerPage}";
$items = $pdo->query($sql)->fetchAll();
// print_r($items);

文件2

<?php require 'my1.php' ?>
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>SHAO's Items</title>
    <link rel="stylesheet" href="style.css">
</head>
<body>
    <table>
        <caption>邵恒头条</caption>
        <thead>
            <tr>
                <td>id</td>
                <td>date</td>
                <td>title</td>
                <td>tags</td>
                <td>action</td>
            </tr>
        </thead>
        <tbody>
            <?php foreach ($items as $item):?>
                <tr>
                     <!-- 短标签来简化变量的显示 -->
                    <td><?=$item['id']?></td>
                    <td><?=$item['date']?></td>
                    <td><?=$item['title']?></td>
                    <td><?=$item['label']?></td>
                    <td><button>编辑</button><button>删除</button></td>
                </tr>
            <?php endforeach ?>
        </tbody>
    </table>
</body>
</html>

主要内容：

1. 文件上传的异常处理

2. 将文件从临时目录移动到正式目录

3. 批量上传文件

4. 分页操作

4-1. 基本知识: 分页原理

4-1-1. 术语

4-1-2. 计算偏移量

4-2. 操作

5. 作业实战

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