在 ColdFusion 中显示数据库中的 BLOB 文件
Display BLOB file from database in ColdFusion
我有一个用户可以上传 PDF 的表单，我将其作为 BLOB 存储在数据库中。我正在显示所有上传的 PDF 的列表，所有这些都可以通过单击下载。我已经尝试了很多不同的解决方法来让 PDF 正确下载，但它会在浏览器中显示“无法加载 PDF 文档”，在 Adobe Acrobat 中显示“文件已损坏且无法修复”。这是我的代码：
Instructors.cfc（上传文件格式）
<form method="post" enctype="multipart/form-data">
<input id="document_filename" name="document_filename" type="hidden">
<input id="document_title" name="document_title" type="hidden">
<input id="openFileBrowser" type="button" value="Import Data from Application PDF" onclick="document.getElementById('application_document').click();">
<input id="application_document" name="application_document" type="file" accept=".pdf" style="display:none">
<input id="upload_document" type="button" onclick="UploadDocument()" style="width:220px; display: none" value="Upload Instructor Application Form">
</form>
<script>
function UploadDocument() {
var fd = new FormData();
var theFile = document.getElementById("application_document").files[0];
fd.append('uploadedFile', theFile);
fd.append('file_name', document.getElementById("document_title").value);
$.ajax({
url: "InstructorForms.cfc?method=getApplicationPDFData",
type: "post",
data: fd,
processData: false,
contentType: false,
cache: false
});
</script>
InstructorForms.cfc（将 PDF blob 插入数据库）
<cffunction name="getApplicationPDFData" access="remote">
<cfset uploadDirectory = "#expandPath('../UPLOADS')#">
<cfif not directoryExists(uploadDirectory)>
<cfdirectory action="create" directory="#uploadDirectory#">
</cfif>
<cfif IsDefined("uploadedFile")>
<cffile action="upload" fileField="uploadedFile" destination="#uploadDirectory#" nameConflict="overwrite" accept="application/pdf">
</cfif>
<cfif IsDefined("file_name")>
<cfset filePath = uploadDirectory & "\" & file_name>
<cfpdfform action="read" source="#filePath#" result="documentStruct" />
<cfset nameArray = documentStruct.Name.split(",")>
<cffile action="readbinary" file="#filePath#" variable="binPDF">
<cfquery name="addPDFToDB" datasource="#request.dsn#">
INSERT INTO DDMS.UPLOADED_FILES (LAST_NAME, FIRST_NAME, DOCUMENT, DOCUMENT_TYPE)
VALUES(<cfqueryparam value="#nameArray[1]#" cfsqltype="cf_sql_varchar">,
<cfqueryparam value="#ltrim(rtrim(nameArray[2]))#" cfsqltype="cf_sql_varchar">,
<cfqueryparam value="#binPDF#" cfsqltype="cf_sql_blob">,
'Instructor Application')
</cfquery>
<cffile action="delete" file="#filePath#">
</cffunction>
Instructors.cfc [再次]（从数据库下载 PDF，我遇到了问题）
<cffunction name="downloadPDF" access="remote" returntype="any">
<cfargument name="uploaded_file_id" required="yes" type="numeric">
<cfquery name="getInstructorApplication" datasource="#request.dsn#" result="output">
SELECT DOCUMENT, FIRST_NAME, LAST_NAME FROM DDMS.UPLOADED_FILES WHERE UPLOADED_FILE_ID = #arguments.uploaded_file_id#
</cfquery>
<cfset fileName = getInstructorApplication.LAST_NAME & "_" & getInstructorApplication.FIRST_NAME & "_application.pdf">
<cfset cfTags = "">
<cfsavecontent variable="cfTags">
<cfheader name="content-disposition" value="attachment; filename=#fileName#">
<cfcontent variable="#getInstructorApplication.DOCUMENT#" type="application/pdf" reset="yes">
</cfsavecontent>
<cfreturn cfTags>
</cffunction>
最重要的代码部分是我包含的 last/above 片段。即使我在浏览器中导航到 downloadPDF 功能，它仍然无法正确下载 PDF 并给出错误消息。因此，清理该方法是第 1 步，然后我实际上可以通过 AJAX 调用检索用户页面上的 PDF，如果有帮助，我也会展示它：
$(".pdfFile").on("click", function() {
var uploaded_file_id = $(this).data("id");
$.ajax({
url: "CFC/Instructors.cfc?method=downloadPDF",
data: { "uploaded_file_id": uploaded_file_id },
success: function(blob, status, xhr) {
var filename = "";
var disposition = xhr.getResponseHeader('Content-Disposition');
if (disposition && disposition.indexOf('attachment') !== -1) {
var filenameRegex = /filename[^;=\n]*=((['"]).*?|[^;\n]*)/;
var matches = filenameRegex.exec(disposition);
if (matches != null && matches[1]) filename = matches[1].replace(/['"]/g, '');
}
if (typeof window.navigator.msSaveBlob !== 'undefined') {
window.navigator.msSaveBlob(blob, filename);
} else {
var URL = window.URL || window.webkitURL;
var newBlob = new Blob([blob], {type: "application/pdf"});
var downloadUrl = URL.createObjectURL(newBlob);
if (filename) {
var a = document.createElement("a");
if (typeof a.download === 'undefined') {
window.location.href = downloadUrl;
} else {
a.href = downloadUrl;
a.download = filename;
document.body.appendChild(a);
a.click();
}
} else {
window.location.href = downloadUrl;
}
}
}
});
});
对于大量的代码，我们深表歉意。但正如我所说，最重要的部分是 downloadPDF 函数，我在其中使用 cfcontent 并需要正确加载二进制数据。任何帮助将不胜感激，因为我已经在这个问题上停留了一段时间并且找不到太多文档。
更新：
返回的 PDF 大小为 62.5 KB，我听说如果禁用 BLOB 检索，由于 ColdFusion Admin 中的缓冲区，输出可能会被截断为 64 KB。我无权访问 ColdFusion Admin，但我的一位同事可以访问，也许他在尝试全局启用 BLOB 检索时编辑了错误的设置。我会和他核实一下。
原来是 ColdFusion Administrator 中的设置导致了问题。尽管在 Dev 环境中 globally 启用了 BLOB 检索，但在我的特定 datasource 上并未启用它。在全局设置中启用 BLOB 检索只是第一步；除非您明确启用它，否则它不会覆盖数据源。
我确实需要稍微调整一下我的代码，但幅度不大。我将 cfcontent 更改为使用 file 属性而不是 variable，我使用 <cffile action="write"> 中使用的路径填充了 file 属性。将文件写入服务器后，我通过 JavaScript 为文件创建锚点 link 并调用其 click() 方法，以便下载 PDF 附件。之后，我在 done() 方法中执行另一个 AJAX 调用来删除文件，因为我不需要将该文件保留在服务器上；这是暂时的。这是我的最终代码：
Instructors.cfc（文件上传形式保持不变）
<cfquery name="getInstructorApplications" datasource="#this.dsn#">
SELECT fm.FILELOB_ID, fm.FILEMETA_ID, fm.TITLE, fm.FILEEXT, fm.FILE_LEN, fm.CREATEDDATE
FROM DDMS.FILEMETA fm
JOIN DDMS.FILELOB fl
ON fm.FILELOB_ID = fl.FILELOB_ID
WHERE fl.DOCUMENT_TYPE = 'Instructor Application'
</cfquery>
<table class="DataTable">
<thead>
<tr>
<th style="width: 200px">File Name</th>
<th>File Extension</th>
<th>File Size</th>
<th>Date Uploaded</th>
</tr>
</thead>
<tbody>
<cfloop query="getInstructorApplications">
<cfoutput>
<tr>
<td style="width: 200px">
<a data-id="#FILELOB_ID#" data-meta-id="#FILEMETA_ID#" data-filename="#TITLE#" class="pdfFile" style="color: blue; cursor: pointer">#TITLE#</a>
</td>
<td>#FILEEXT#</td>
<td>#FILE_LEN#</td>
<td>#DATEFORMAT(LEFT(CREATEDDATE, 10))#</td>
</tr>
</cfoutput>
</cfloop>
</tbody>
</table>
<script>
$(".pdfFile").on("click", function() {
var file_id = $(this).data("id");
var file_meta_id = $(this).data("meta-id");
var file_name = $(this).data("filename");
var now = new Date();
var ticks = now.getTime();
<cfoutput>
var #ToScript(cfcPath, "cfcRoot")#;
</cfoutput>
$.ajax({
url: cfcRoot + "CFC/FileManager.cfc?method=ServeFileDownload&random=" + ticks,
type: "post",
data: { "FileID": file_id,
"FileMetaID": file_meta_id,
"fileName": file_name },
success: function() {
var a = document.createElement("a");
a.href = cfcRoot + "UPLOADS/" + file_name;
a.download = file_name;
document.body.appendChild(a);
a.click();
}
}).done(function() {
$.ajax({
url: cfcRoot + "CFC/FileManager.cfc?method=DeleteFile&random=" + ticks,
data: { "fileName": file_name }
});
});
});
</script>
FileManager.cfc（新建文件，接管InstructorForms.cfc）
<cffunction name="ServeFileDownload" access="remote" returntype="void">
<cfargument name="FileID" type="numeric" required="no" default=0>
<cfargument name="FileMetaID" type="numeric" required="no" default=0>
<cfargument name="fileName" type="string" required="no" default="">
<cfif ARGUMENTS.FileID NEQ 0>
<cfset local.FileMetaID = GetCurrentMetaIDByFileID(FileID=ARGUMENTS.FileID)>
<cfelse>
<cfset local.FileMetaID = ARGUMENTS.FileMetaID>
</cfif>
<cfif local.FileMetaID NEQ 0>
<cfset ServeFile( FileMetaID=ARGUMENTS.FileMetaID, ServeType="attachment", filename="#ARGUMENTS.fileName#")>
<cfelse>
<cfreturn "">
</cfif>
</cffunction>
<cffunction name="ServeFile" access="public" returntype="void">
<cfargument name="FileMetaID" type="numeric" required="yes">
<cfargument name="ServeType" type="string" required="yes">
<cfargument name="fileName" type="string" required="no" default="">
<cfquery name="GetFileMetaData" datasource="#application.DDMS.dsn#">
SELECT fm.FILEMETA_ID, fm.FILELOB_ID, fl.FILELOB, fm.FILE_ID, fm.TITLE, fm.FILEEXT, fm.MIMETYPE_ID, fm.FILE_LEN
FROM DDMS.FILEMETA fm
JOIN DDMS.FILELOB fl
ON fm.FILELOB_ID = fl.FILELOB_ID
WHERE fm.FILEMETA_ID = <cfqueryparam cfsqltype="CF_SQL_INTEGER" value="#ARGUMENTS.FileMetaID#">
AND fm.ISACTIVE = 1
</cfquery>
<cfset MIMETypeObj = CreateObject("component","#application.global.cfcpath#.filemanager.mimetype")>
<cfset local.filename = Len(ARGUMENTS.fileName) ? "#ARGUMENTS.fileName#" : "#GetFileMetaData.TITLE#">
<cfset local.MIMETYPE = MIMETypeObj.GetMIMETypeByID(MIMETYPEID=GetFileMetaData.MIMETYPE_ID)>
<cfif ARGUMENTS.ServeType EQ "attachment">
<cfset local.MIMETYPE = "application/octet-stream">
</cfif>
<cfset uploadDirectory = "#expandPath('../UPLOADS')#">
<cfset filePath = uploadDirectory & "\" & arguments.fileName>
<cfset RecordDownloadUsage(FILEMETAID=ARGUMENTS.FileMetaID,FILENAME="#local.filename#")>
<cffile action="write" file="#filePath#" output="#GetFileMetaData.FileLOB#" >
<cfheader name="Content-Disposition" value="#ARGUMENTS.ServeType#;filename=#local.filename#;" />
<cfcontent file="#filePath#" type="#local.MIMETYPE#" />
<cfreturn ToString(uploadDirectory & "/" & arguments.fileName)>
</cffunction>
<cffunction name="DeleteFile" access="remote" returntype="void">
<cfargument name="fileName" type="string" required="yes">
<cfset uploadDirectory = "#expandPath('../UPLOADS')#">
<cfset filePath = uploadDirectory & "\" & arguments.fileName>
<cffile action="delete" file="#filePath#">
</cffunction>
我有一个用户可以上传 PDF 的表单，我将其作为 BLOB 存储在数据库中。我正在显示所有上传的 PDF 的列表，所有这些都可以通过单击下载。我已经尝试了很多不同的解决方法来让 PDF 正确下载，但它会在浏览器中显示“无法加载 PDF 文档”，在 Adobe Acrobat 中显示“文件已损坏且无法修复”。这是我的代码：
Instructors.cfc（上传文件格式）
<form method="post" enctype="multipart/form-data">
<input id="document_filename" name="document_filename" type="hidden">
<input id="document_title" name="document_title" type="hidden">
<input id="openFileBrowser" type="button" value="Import Data from Application PDF" onclick="document.getElementById('application_document').click();">
<input id="application_document" name="application_document" type="file" accept=".pdf" style="display:none">
<input id="upload_document" type="button" onclick="UploadDocument()" style="width:220px; display: none" value="Upload Instructor Application Form">
</form>
<script>
function UploadDocument() {
var fd = new FormData();
var theFile = document.getElementById("application_document").files[0];
fd.append('uploadedFile', theFile);
fd.append('file_name', document.getElementById("document_title").value);
$.ajax({
url: "InstructorForms.cfc?method=getApplicationPDFData",
type: "post",
data: fd,
processData: false,
contentType: false,
cache: false
});
</script>
InstructorForms.cfc（将 PDF blob 插入数据库）
<cffunction name="getApplicationPDFData" access="remote">
<cfset uploadDirectory = "#expandPath('../UPLOADS')#">
<cfif not directoryExists(uploadDirectory)>
<cfdirectory action="create" directory="#uploadDirectory#">
</cfif>
<cfif IsDefined("uploadedFile")>
<cffile action="upload" fileField="uploadedFile" destination="#uploadDirectory#" nameConflict="overwrite" accept="application/pdf">
</cfif>
<cfif IsDefined("file_name")>
<cfset filePath = uploadDirectory & "\" & file_name>
<cfpdfform action="read" source="#filePath#" result="documentStruct" />
<cfset nameArray = documentStruct.Name.split(",")>
<cffile action="readbinary" file="#filePath#" variable="binPDF">
<cfquery name="addPDFToDB" datasource="#request.dsn#">
INSERT INTO DDMS.UPLOADED_FILES (LAST_NAME, FIRST_NAME, DOCUMENT, DOCUMENT_TYPE)
VALUES(<cfqueryparam value="#nameArray[1]#" cfsqltype="cf_sql_varchar">,
<cfqueryparam value="#ltrim(rtrim(nameArray[2]))#" cfsqltype="cf_sql_varchar">,
<cfqueryparam value="#binPDF#" cfsqltype="cf_sql_blob">,
'Instructor Application')
</cfquery>
<cffile action="delete" file="#filePath#">
</cffunction>
Instructors.cfc [再次]（从数据库下载 PDF，我遇到了问题）
<cffunction name="downloadPDF" access="remote" returntype="any">
<cfargument name="uploaded_file_id" required="yes" type="numeric">
<cfquery name="getInstructorApplication" datasource="#request.dsn#" result="output">
SELECT DOCUMENT, FIRST_NAME, LAST_NAME FROM DDMS.UPLOADED_FILES WHERE UPLOADED_FILE_ID = #arguments.uploaded_file_id#
</cfquery>
<cfset fileName = getInstructorApplication.LAST_NAME & "_" & getInstructorApplication.FIRST_NAME & "_application.pdf">
<cfset cfTags = "">
<cfsavecontent variable="cfTags">
<cfheader name="content-disposition" value="attachment; filename=#fileName#">
<cfcontent variable="#getInstructorApplication.DOCUMENT#" type="application/pdf" reset="yes">
</cfsavecontent>
<cfreturn cfTags>
</cffunction>
最重要的代码部分是我包含的 last/above 片段。即使我在浏览器中导航到 downloadPDF 功能，它仍然无法正确下载 PDF 并给出错误消息。因此，清理该方法是第 1 步，然后我实际上可以通过 AJAX 调用检索用户页面上的 PDF，如果有帮助，我也会展示它：
$(".pdfFile").on("click", function() {
var uploaded_file_id = $(this).data("id");
$.ajax({
url: "CFC/Instructors.cfc?method=downloadPDF",
data: { "uploaded_file_id": uploaded_file_id },
success: function(blob, status, xhr) {
var filename = "";
var disposition = xhr.getResponseHeader('Content-Disposition');
if (disposition && disposition.indexOf('attachment') !== -1) {
var filenameRegex = /filename[^;=\n]*=((['"]).*?|[^;\n]*)/;
var matches = filenameRegex.exec(disposition);
if (matches != null && matches[1]) filename = matches[1].replace(/['"]/g, '');
}
if (typeof window.navigator.msSaveBlob !== 'undefined') {
window.navigator.msSaveBlob(blob, filename);
} else {
var URL = window.URL || window.webkitURL;
var newBlob = new Blob([blob], {type: "application/pdf"});
var downloadUrl = URL.createObjectURL(newBlob);
if (filename) {
var a = document.createElement("a");
if (typeof a.download === 'undefined') {
window.location.href = downloadUrl;
} else {
a.href = downloadUrl;
a.download = filename;
document.body.appendChild(a);
a.click();
}
} else {
window.location.href = downloadUrl;
}
}
}
});
});
对于大量的代码，我们深表歉意。但正如我所说，最重要的部分是 downloadPDF 函数，我在其中使用 cfcontent 并需要正确加载二进制数据。任何帮助将不胜感激，因为我已经在这个问题上停留了一段时间并且找不到太多文档。
更新：
返回的 PDF 大小为 62.5 KB，我听说如果禁用 BLOB 检索，由于 ColdFusion Admin 中的缓冲区，输出可能会被截断为 64 KB。我无权访问 ColdFusion Admin，但我的一位同事可以访问，也许他在尝试全局启用 BLOB 检索时编辑了错误的设置。我会和他核实一下。
原来是 ColdFusion Administrator 中的设置导致了问题。尽管在 Dev 环境中 globally 启用了 BLOB 检索，但在我的特定 datasource 上并未启用它。在全局设置中启用 BLOB 检索只是第一步；除非您明确启用它，否则它不会覆盖数据源。
我确实需要稍微调整一下我的代码，但幅度不大。我将 cfcontent 更改为使用 file 属性而不是 variable，我使用 <cffile action="write"> 中使用的路径填充了 file 属性。将文件写入服务器后，我通过 JavaScript 为文件创建锚点 link 并调用其 click() 方法，以便下载 PDF 附件。之后，我在 done() 方法中执行另一个 AJAX 调用来删除文件，因为我不需要将该文件保留在服务器上；这是暂时的。这是我的最终代码：
Instructors.cfc（文件上传形式保持不变）
<cfquery name="getInstructorApplications" datasource="#this.dsn#">
SELECT fm.FILELOB_ID, fm.FILEMETA_ID, fm.TITLE, fm.FILEEXT, fm.FILE_LEN, fm.CREATEDDATE
FROM DDMS.FILEMETA fm
JOIN DDMS.FILELOB fl
ON fm.FILELOB_ID = fl.FILELOB_ID
WHERE fl.DOCUMENT_TYPE = 'Instructor Application'
</cfquery>
<table class="DataTable">
<thead>
<tr>
<th style="width: 200px">File Name</th>
<th>File Extension</th>
<th>File Size</th>
<th>Date Uploaded</th>
</tr>
</thead>
<tbody>
<cfloop query="getInstructorApplications">
<cfoutput>
<tr>
<td style="width: 200px">
<a data-id="#FILELOB_ID#" data-meta-id="#FILEMETA_ID#" data-filename="#TITLE#" class="pdfFile" style="color: blue; cursor: pointer">#TITLE#</a>
</td>
<td>#FILEEXT#</td>
<td>#FILE_LEN#</td>
<td>#DATEFORMAT(LEFT(CREATEDDATE, 10))#</td>
</tr>
</cfoutput>
</cfloop>
</tbody>
</table>
<script>
$(".pdfFile").on("click", function() {
var file_id = $(this).data("id");
var file_meta_id = $(this).data("meta-id");
var file_name = $(this).data("filename");
var now = new Date();
var ticks = now.getTime();
<cfoutput>
var #ToScript(cfcPath, "cfcRoot")#;
</cfoutput>
$.ajax({
url: cfcRoot + "CFC/FileManager.cfc?method=ServeFileDownload&random=" + ticks,
type: "post",
data: { "FileID": file_id,
"FileMetaID": file_meta_id,
"fileName": file_name },
success: function() {
var a = document.createElement("a");
a.href = cfcRoot + "UPLOADS/" + file_name;
a.download = file_name;
document.body.appendChild(a);
a.click();
}
}).done(function() {
$.ajax({
url: cfcRoot + "CFC/FileManager.cfc?method=DeleteFile&random=" + ticks,
data: { "fileName": file_name }
});
});
});
</script>
FileManager.cfc（新建文件，接管InstructorForms.cfc）
<cffunction name="ServeFileDownload" access="remote" returntype="void">
<cfargument name="FileID" type="numeric" required="no" default=0>
<cfargument name="FileMetaID" type="numeric" required="no" default=0>
<cfargument name="fileName" type="string" required="no" default="">
<cfif ARGUMENTS.FileID NEQ 0>
<cfset local.FileMetaID = GetCurrentMetaIDByFileID(FileID=ARGUMENTS.FileID)>
<cfelse>
<cfset local.FileMetaID = ARGUMENTS.FileMetaID>
</cfif>
<cfif local.FileMetaID NEQ 0>
<cfset ServeFile( FileMetaID=ARGUMENTS.FileMetaID, ServeType="attachment", filename="#ARGUMENTS.fileName#")>
<cfelse>
<cfreturn "">
</cfif>
</cffunction>
<cffunction name="ServeFile" access="public" returntype="void">
<cfargument name="FileMetaID" type="numeric" required="yes">
<cfargument name="ServeType" type="string" required="yes">
<cfargument name="fileName" type="string" required="no" default="">
<cfquery name="GetFileMetaData" datasource="#application.DDMS.dsn#">
SELECT fm.FILEMETA_ID, fm.FILELOB_ID, fl.FILELOB, fm.FILE_ID, fm.TITLE, fm.FILEEXT, fm.MIMETYPE_ID, fm.FILE_LEN
FROM DDMS.FILEMETA fm
JOIN DDMS.FILELOB fl
ON fm.FILELOB_ID = fl.FILELOB_ID
WHERE fm.FILEMETA_ID = <cfqueryparam cfsqltype="CF_SQL_INTEGER" value="#ARGUMENTS.FileMetaID#">
AND fm.ISACTIVE = 1
</cfquery>
<cfset MIMETypeObj = CreateObject("component","#application.global.cfcpath#.filemanager.mimetype")>
<cfset local.filename = Len(ARGUMENTS.fileName) ? "#ARGUMENTS.fileName#" : "#GetFileMetaData.TITLE#">
<cfset local.MIMETYPE = MIMETypeObj.GetMIMETypeByID(MIMETYPEID=GetFileMetaData.MIMETYPE_ID)>
<cfif ARGUMENTS.ServeType EQ "attachment">
<cfset local.MIMETYPE = "application/octet-stream">
</cfif>
<cfset uploadDirectory = "#expandPath('../UPLOADS')#">
<cfset filePath = uploadDirectory & "\" & arguments.fileName>
<cfset RecordDownloadUsage(FILEMETAID=ARGUMENTS.FileMetaID,FILENAME="#local.filename#")>
<cffile action="write" file="#filePath#" output="#GetFileMetaData.FileLOB#" >
<cfheader name="Content-Disposition" value="#ARGUMENTS.ServeType#;filename=#local.filename#;" />
<cfcontent file="#filePath#" type="#local.MIMETYPE#" />
<cfreturn ToString(uploadDirectory & "/" & arguments.fileName)>
</cffunction>
<cffunction name="DeleteFile" access="remote" returntype="void">
<cfargument name="fileName" type="string" required="yes">
<cfset uploadDirectory = "#expandPath('../UPLOADS')#">
<cfset filePath = uploadDirectory & "\" & arguments.fileName>
<cffile action="delete" file="#filePath#">
</cffunction>