渲染PDF文件並使用grails渲染和Attachmentable插件保存到對象

Question

我試圖生成一個包含對象信息的PDF文件，然后將其附加到存儲在數據庫中的另一個對象。 我正在使用的可附件插件現在可以用於用戶端附件，但是我需要我的系統能夠自動執行此操作。

我在用：
Grails 1.3.9
可附加的0.3.0 http://grails.org/plugin/attachmentable
渲染0.4.3 http://grails.org/plugin/rendering

我已經能夠生成和顯示pdf，但不知道如何使用可附加附件來附加它。 我需要某種方式來生成生成的pdf字節數組，並將其轉換為MultipartFile，以供我調用的可附加插件功能。 我得到的錯誤表明我的參數類型無效。

我保存了object1和object2，然后生成object1的pdf，然后嘗試將其附加到object2。

預先感謝您的幫助！

Thing1控制器片段：

ByteArrayOutputStream bytes = pdfRenderingService.render(template: "/thing1/pdf", model: [thing1: thing1])

attachmentableService.addAttachment("unknown", thing2.id, bytes)

我正在嘗試調用AttachmentableService函數：

def addAttachment(def poster, def reference, CommonsMultipartFile file) {
    addAttachment(CH.config, poster, reference, file)
}

def addAttachment(def config,
                  def poster,
                  def reference,
                  CommonsMultipartFile file) {

    if (reference.ident() == null) {
        throw new AttachmentableException(
            "You must save the entity [${delegate}] before calling addAttachment.")
    }

    if (!file?.size) {
        throw new EmptyFileException(file.name, file.originalFilename)
    }

    String delegateClassName = AttachmentableUtil.fixClassName(reference.class)
    String posterClass = (poster instanceof String) ? poster : AttachmentableUtil.fixClassName(poster.class.name)
    Long posterId = (poster instanceof String) ? 0L : poster.id
    String filename = file.originalFilename

    // link
    def link = AttachmentLink.findByReferenceClassAndReferenceId(
            delegateClassName, reference.ident())
    if (!link) {
        link = new AttachmentLink(
                referenceClass: delegateClassName,
                referenceId: reference.ident())
    }

    // attachment
    Attachment attachment = new Attachment(
            // file
            name: FilenameUtils.getBaseName(filename),
            ext: FilenameUtils.getExtension(filename),
            length: 0L,
            contentType: file.contentType,
            // poster
            posterClass: posterClass,
            posterId: posterId,
            // input
            inputName: file.name)
    link.addToAttachments attachment

    if (!link.save(flush: true)) {
        throw new AttachmentableException(
                "Cannot create Attachment for arguments [$user, $file], they are invalid.")
    }

    // save file to disk
    File diskFile = AttachmentableUtil.getFile(config, attachment, true)
    file.transferTo(diskFile)

    attachment.length = diskFile.length()

    // interceptors
    if(reference.respondsTo('onAddAttachment')) {
        reference.onAddAttachment(attachment)
    }

    attachment.save(flush:true) // Force update so searchable can try to index it again.

    return reference
}

Grails運行時錯誤：

groovy.lang.MissingMethodException: No signature of method: com.macrobit.grails.plugins.attachmentable.services.AttachmentableService.addAttachment() is applicable for argument types: (java.lang.String, java.lang.Long, java.io.ByteArrayOutputStream) values: [unknown, 80536, %PDF-1.4 and a long string of unreadable data...]
Possible solutions: addAttachment(java.lang.Object, java.lang.Object, org.springframework.web.multipart.commons.CommonsMultipartFile), addAttachment(java.lang.Object, java.lang.Object, java.lang.Object, org.springframework.web.multipart.commons.CommonsMultipartFile)

我添加的服務方法：

def customAddMethod(def poster, def reference, def pdfBytes) {
    customAddMethod(CH.config, poster, reference, pdfBytes)
}

def customAddMethod(def config,
                  def poster,
                  def reference,
                  def pdfBytes) {

    if (reference.ident() == null) {
        throw new AttachmentableException(
            "You must save the entity [${delegate}] before calling customAddMethod.")
    }

    String delegateClassName = AttachmentableUtil.fixClassName(reference.class)
    String posterClass = (poster instanceof String) ? poster : AttachmentableUtil.fixClassName(poster.class.name)
    Long posterId = (poster instanceof String) ? 0L : poster.id
    String filename = "File Name"

    // link
    def link = AttachmentLink.findByReferenceClassAndReferenceId(
            delegateClassName, reference.ident())

    if (!link) {
        link = new AttachmentLink(
                referenceClass: delegateClassName,
                referenceId: reference.ident())
    }

    // attachment
    Attachment attachment = new Attachment(
            // file
            name: "File Name",
            ext: "pdf",
            length: 0L,
            contentType: "application/pdf",
            // poster
            posterClass: posterClass,
            posterId: posterId,
            // input
            inputName: "File Name")
    link.addToAttachments attachment

    if (!link.save(flush: true)) {
        throw new AttachmentableException(
                "Cannot create Attachment for arguments [$user, $file], they are invalid.")
    }

    // save file to disk
    byte[] bytes = pdfBytes.toByteArray(); //convert ByteArrayOutputStream to ByteArray

    File diskFile = AttachmentableUtil.getFile(config, attachment, true) //file path
    FileOutputStream fos = new FileOutputStream(diskFile); //open file output stream to write to
    fos.write(bytes); //write rendered pdf bytes to file
    fos.flush();
    fos.close();

    attachment.length = diskFile.length()

    // interceptors
    if(reference.respondsTo('onAddAttachment')) {
        reference.onAddAttachment(attachment)
    }

    attachment.save(flush:true) // Force update so searchable can try to index it again.

    return reference
}

Answer 1

好像您引用的AttachmentableService（來自Attachmentable插件）假定它正在處理文件上載情況，因此您可以通過request.getFile（）輕松獲取MultipartFile實例。 事實並非如此-您正在通過“渲染”插件創建文件，並且希望將該文件附加到域對象，對嗎？

您可以嘗試通過首先將pdf字節寫入磁盤，然后通過DiskFileItemFactory創建DiskFileItem來手動構造CommonsMultipartFile實例。 請參閱這篇文章，以了解我的想法： 如何從絕對文件路徑制作CommonsMultipartFile？

另一個更好的選擇可能是簽出該插件的源代碼，並添加不需要您進行旋轉的方法-也許是addAttachment方法的版本，該方法可以接受File或OutputStream-並將PR提交給插件作者。 （看起來他們正在為合格的域對象添加“ addAttachment”方法，這也需要一個CommonsMultipartFile）。

否則，您可能只需要創建自己的服務即可提供基本的最終結果，這顯然是創建AttachmentLink和關聯的Attachment實例。