Tips for back-end processing of file uploads in PHP

This article mainly introduces the PHP file upload back-end processing tips in detail to help you better perform file upload operations. Interested friends can refer to

This article will talk about it. What are the techniques for back-end processing of PHP file uploads?

Business Scenario 1 We will only select a single file to upload, and there is no need to do any immediate verification work. Then, maybe there is no optimization at all, because in the end, all you have to do is to put this file in the form and submit it together, and then process it directly!

Business Scenario 2. Multiple files need to be uploaded, and the internal content of the files needs to be verified from time to time and displayed on the corresponding page. In this case, after the user chooses to upload the file, we need to upload the file immediately, because we need to read the information in the file, and when submitting at the end, we also need to submit the file once. Obviously, there is a repetitive upload task here. One consumes user time, and the other consumes server bandwidth resources! Optimization, the conceivable method is also very simple. After uploading the file for the first time, can the file be kept on the server, and when the form is actually submitted, just read the uploaded temporary file. Yes, this is our approach!

Business scenario three is similar to scenario two. Multiple files need to be uploaded, but multiple files may be uploaded separately. That is, we may have uploaded 10M for the first time, 10M for the second time, and uploaded 10 times in total. Then, on the server side, the one-time submission must have exceeded the upload size limit, but if we are It’s okay to upload each time, and when submitting at the end, we only need to upload a short text message!

The idea is indeed simple, and it seems that there is no problem. However, maybe my ability is limited, and it really took me a lot of time to deal with this! Below, I will give some sample code for reference:

File upload skills (single uploaded files exist as temporary files on the server side) Sample code:

1. Page js processing

    //点击选择完成文件后，触发上传文件操作，将文件上传至服务器临时目录
    $('.upload-real-file').off().on('change', function(){
      if(!$(this).val()){
        return false;
      }
      var responseObjId = $(this).attr('response-id');
      var responseObj = $('#' + responseObjId);
      $('#Form').ajaxSubmit({
        url:'/aa/bb/uploadTmpApkTool',
        resetForm: false,
        dataType: 'json',
        beforeSubmit: function(option){
          window.loading = layer.load(2);
        },
        success: function(data, statusText){
          layer.close(window.loading);
          if(data.status == 1){
            responseObj.html(data.apkInfoHtml);
            var parentContainer = responseObj.parent().parent(),
              nameContainer = parentContainer.find('.file-name-container');
            nameContainer.html(data.apkName);
            nameContainer.attr('title', data.apkName);
            responseObj.find('.file-tmp').html(data.fileInfo); //将文件信息存放于隐藏域中，以便在提交时能找到  
            $(submitId).removeAttr('disabled');
          }else{
            layer.alert(data.info);
          }
        },
        error: function(data){
          layer.close(window.loading);
          layer.alert('未知错误，请稍后再试！');
        }
      });
      return false;//防止dialog 自动关闭
    });

2. Obviously, the page needs to obtain file information and perform background processing Code (PHP)

    $apkConfig = $this->_getApkConfig();
    $params = $this->getFilteredParam('get');
    $subFile = $_FILES['apkToolFiles'];
    $apkName = $apkInfoHtml = "";
    if(empty($subFile))
    {
      $this->ajaxReturn(array('status' => -4, 'info' => '请选择要上传的文件'));
    }

    foreach ($subFile['name'] as $subKey => $subVal)
    {
      if ($subFile['name'][$subKey])
      {
        $fileData = $this->_getFileData($subFile, $subKey);
        $checkData = array(
          'maxSize' => $apkConfig['FILE_MAX_SIZE'],
          'savePath' => $apkConfig['TMP_CHILD_PATH'],
          'extArr' => array('apk'),
          'releaseName' => str_replace('.apk', '', $fileData['fileName']), //特有
        );
        $checkResult = $this->_checkFileData($fileData, $checkData);
        if ($checkResult['status'] != 1)
        {
          $this->ajaxReturn($checkResult);
        }
        //移动文件
        $filePath = $checkData['savePath'] . '/' . $fileData['fileName'] . '.tmp' . genRandStr(6);;
        $this->_moveUploadedFile($fileData['tmpName'], $filePath);
        $apkInfo = $this->_apkParser($filePath); //解析
        if($apkInfo['UMENG_CHANNEL'] != 'UMENG_CHANNEL_VALUE')
        {
          @unlink($filePath);               //删除无效文件
          $this->ajaxReturn(array('status' => 0, 'info' => "UMENG_CHANNEL的值要是 UMENG_CHANNEL_VALUE才行"));
        }
        $tmpFileArr['file_info'] = array(
          'name' => $subFile['name'][$subKey],
          'type' => $subFile['type'][$subKey],
          'tmp_name' => str_replace($apkConfig['TMP_CHILD_PATH'] . '/', '', $filePath),
          'error' => $subFile['error'][$subKey],
          'size' => $subFile['size'][$subKey],
        );       //转存该值，不再重复上传文件
      }
      else
      {
        $this->ajaxReturn(array('status' => 0, 'info' => "文件不能为空"));
      }
      foreach ($apkInfo as $key => $val)
      {
        $apkInfoHtml .= "{$key}:{$val} \r\n";
      }
      $apkName = $fileData['fileName'];
      $version = $apkInfo['versionName'];
    }
    $fileInfo = htmlspecialchars(json_encode($tmpFileArr['file_info']));
    $fileInfoHtml = "<input name=\"apkToolFileTmp[]\" value=&#39;{$fileInfo}&#39; type=\"hidden\"/>";  //一定要输出前使用htmlspecialchars, 否则不能正确显示页面值和获取至正确的文件信息

    $this->ajaxReturn(array(&#39;status&#39; => 1, &#39;info&#39; => "上传成功", &#39;version&#39; => $version, &#39;item&#39; => $item, &#39;apkName&#39; => $apkName, &#39;apkInfoHtml&#39; => $apkInfoHtml, &#39;fileInfo&#39; => $fileInfoHtml));
  }

3. By combining the two parts of code, we already have the correct information on the page, Just don't submit the file to the server when you submit the form at the end. When processing on the server side, just move the temporary file uploaded before, and you're done!

$('.upload-file-real').attr('disabled', 'disabled'); //Disable uploading files before submitting the form

4. Follow-up work

After uploading the temporary file to the server, there is no way to determine whether the user cancels the current operation. If canceled, the temporary file will always exist on the server. , so we need a script to regularly clean up the temporary directory. Of course, this is very simple. You only need to find this directory and compare the time. For example, files older than one day will be deleted. Just pay attention to controlling the frequency of cleaning!

5. Digression

Log is really important, where did something go wrong, where did the file get deleted, where After cleaning the database, be sure to keep records!

Upload files to the temporary directory of the server. The back-end processing principle seems very simple, but it also requires you to debug it carefully. At least when I was doing this small function, it took a lot of effort to figure it out!

Summary: The above is the entire content of this article, I hope it will be helpful to everyone's study.

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