Spring Framework

org.springframework.web.servlet.view.document
Class AbstractPdfView

java.lang.Object
  extended by org.springframework.context.support.ApplicationObjectSupport
      extended by org.springframework.web.context.support.WebApplicationObjectSupport
          extended by org.springframework.web.servlet.view.AbstractView
              extended by org.springframework.web.servlet.view.document.AbstractPdfView
All Implemented Interfaces:
Aware, BeanNameAware, ApplicationContextAware, ServletContextAware, View

public abstract class AbstractPdfView
extends AbstractView

Abstract superclass for PDF views, using Bruno Lowagie's iText package. Application-specific view classes will extend this class. The view will be held in the subclass itself, not in a template.

Note: Internet Explorer requires a ".pdf" extension, as it doesn't always respect the declared content type.

Author:
Rod Johnson, Juergen Hoeller, Jean-Pierre Pawlak
See Also:
AbstractPdfStamperView

Field Summary
 
Fields inherited from class org.springframework.web.servlet.view.AbstractView
DEFAULT_CONTENT_TYPE
 
Fields inherited from class org.springframework.context.support.ApplicationObjectSupport
logger
 
Fields inherited from interface org.springframework.web.servlet.View
PATH_VARIABLES, RESPONSE_STATUS_ATTRIBUTE
 
Constructor Summary
AbstractPdfView()
          This constructor sets the appropriate content type "application/pdf".
 
Method Summary
protected abstract  void buildPdfDocument(java.util.Map<java.lang.String,java.lang.Object> model, com.lowagie.text.Document document, com.lowagie.text.pdf.PdfWriter writer, javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response)
          Subclasses must implement this method to build an iText PDF document, given the model.
protected  void buildPdfMetadata(java.util.Map<java.lang.String,java.lang.Object> model, com.lowagie.text.Document document, javax.servlet.http.HttpServletRequest request)
          Populate the iText Document's meta fields (author, title, etc.).
protected  boolean generatesDownloadContent()
          Return whether this view generates download content (typically binary content like PDF or Excel files).
protected  int getViewerPreferences()
          Return the viewer preferences for the PDF file.
protected  com.lowagie.text.Document newDocument()
          Create a new document to hold the PDF contents.
protected  com.lowagie.text.pdf.PdfWriter newWriter(com.lowagie.text.Document document, java.io.OutputStream os)
          Create a new PdfWriter for the given iText Document.
protected  void prepareWriter(java.util.Map<java.lang.String,java.lang.Object> model, com.lowagie.text.pdf.PdfWriter writer, javax.servlet.http.HttpServletRequest request)
          Prepare the given PdfWriter.
protected  void renderMergedOutputModel(java.util.Map<java.lang.String,java.lang.Object> model, javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response)
          Subclasses must implement this method to actually render the view.
 
Methods inherited from class org.springframework.web.servlet.view.AbstractView
addStaticAttribute, createMergedOutputModel, createRequestContext, createTemporaryOutputStream, exposeModelAsRequestAttributes, getAttributesMap, getBeanName, getContentType, getRequestContextAttribute, getStaticAttributes, isExposePathVariables, prepareResponse, render, setAttributes, setAttributesCSV, setAttributesMap, setBeanName, setContentType, setExposePathVariables, setRequestContextAttribute, toString, writeToResponse
 
Methods inherited from class org.springframework.web.context.support.WebApplicationObjectSupport
getServletContext, getTempDir, getWebApplicationContext, initApplicationContext, initServletContext, isContextRequired, setServletContext
 
Methods inherited from class org.springframework.context.support.ApplicationObjectSupport
getApplicationContext, getMessageSourceAccessor, initApplicationContext, requiredContextClass, setApplicationContext
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
 

Constructor Detail

AbstractPdfView

public AbstractPdfView()
This constructor sets the appropriate content type "application/pdf". Note that IE won't take much notice of this, but there's not a lot we can do about this. Generated documents should have a ".pdf" extension.

Method Detail

generatesDownloadContent

protected boolean generatesDownloadContent()
Description copied from class: AbstractView
Return whether this view generates download content (typically binary content like PDF or Excel files).

The default implementation returns false. Subclasses are encouraged to return true here if they know that they are generating download content that requires temporary caching on the client side, typically via the response OutputStream.

Overrides:
generatesDownloadContent in class AbstractView
See Also:
AbstractView.prepareResponse(javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse), ServletResponse.getOutputStream()

renderMergedOutputModel

protected final void renderMergedOutputModel(java.util.Map<java.lang.String,java.lang.Object> model,
                                             javax.servlet.http.HttpServletRequest request,
                                             javax.servlet.http.HttpServletResponse response)
                                      throws java.lang.Exception
Description copied from class: AbstractView
Subclasses must implement this method to actually render the view.

The first step will be preparing the request: In the JSP case, this would mean setting model objects as request attributes. The second step will be the actual rendering of the view, for example including the JSP via a RequestDispatcher.

Specified by:
renderMergedOutputModel in class AbstractView
Parameters:
model - combined output Map (never null), with dynamic values taking precedence over static attributes
request - current HTTP request
response - current HTTP response
Throws:
java.lang.Exception - if rendering failed

newDocument

protected com.lowagie.text.Document newDocument()
Create a new document to hold the PDF contents.

By default returns an A4 document, but the subclass can specify any Document, possibly parameterized via bean properties defined on the View.

Returns:
the newly created iText Document instance
See Also:
Document.Document(com.lowagie.text.Rectangle)

newWriter

protected com.lowagie.text.pdf.PdfWriter newWriter(com.lowagie.text.Document document,
                                                   java.io.OutputStream os)
                                            throws com.lowagie.text.DocumentException
Create a new PdfWriter for the given iText Document.

Parameters:
document - the iText Document to create a writer for
os - the OutputStream to write to
Returns:
the PdfWriter instance to use
Throws:
com.lowagie.text.DocumentException - if thrown during writer creation

prepareWriter

protected void prepareWriter(java.util.Map<java.lang.String,java.lang.Object> model,
                             com.lowagie.text.pdf.PdfWriter writer,
                             javax.servlet.http.HttpServletRequest request)
                      throws com.lowagie.text.DocumentException
Prepare the given PdfWriter. Called before building the PDF document, that is, before the call to Document.open().

Useful for registering a page event listener, for example. The default implementation sets the viewer preferences as returned by this class's getViewerPreferences() method.

Parameters:
model - the model, in case meta information must be populated from it
writer - the PdfWriter to prepare
request - in case we need locale etc. Shouldn't look at attributes.
Throws:
com.lowagie.text.DocumentException - if thrown during writer preparation
See Also:
Document.open(), PdfWriter.setPageEvent(com.lowagie.text.pdf.PdfPageEvent), PdfWriter.setViewerPreferences(int), getViewerPreferences()

getViewerPreferences

protected int getViewerPreferences()
Return the viewer preferences for the PDF file.

By default returns AllowPrinting and PageLayoutSinglePage, but can be subclassed. The subclass can either have fixed preferences or retrieve them from bean properties defined on the View.

Returns:
an int containing the bits information against PdfWriter definitions
See Also:
PdfWriter.AllowPrinting, PdfWriter.PageLayoutSinglePage

buildPdfMetadata

protected void buildPdfMetadata(java.util.Map<java.lang.String,java.lang.Object> model,
                                com.lowagie.text.Document document,
                                javax.servlet.http.HttpServletRequest request)
Populate the iText Document's meta fields (author, title, etc.).
Default is an empty implementation. Subclasses may override this method to add meta fields such as title, subject, author, creator, keywords, etc. This method is called after assigning a PdfWriter to the Document and before calling document.open().

Parameters:
model - the model, in case meta information must be populated from it
document - the iText document being populated
request - in case we need locale etc. Shouldn't look at attributes.
See Also:
Document.addTitle(java.lang.String), Document.addSubject(java.lang.String), Document.addKeywords(java.lang.String), Document.addAuthor(java.lang.String), Document.addCreator(java.lang.String), Document.addProducer(), Document.addCreationDate(), Document.addHeader(java.lang.String, java.lang.String)

buildPdfDocument

protected abstract void buildPdfDocument(java.util.Map<java.lang.String,java.lang.Object> model,
                                         com.lowagie.text.Document document,
                                         com.lowagie.text.pdf.PdfWriter writer,
                                         javax.servlet.http.HttpServletRequest request,
                                         javax.servlet.http.HttpServletResponse response)
                                  throws java.lang.Exception
Subclasses must implement this method to build an iText PDF document, given the model. Called between Document.open() and Document.close() calls.

Note that the passed-in HTTP response is just supposed to be used for setting cookies or other HTTP headers. The built PDF document itself will automatically get written to the response after this method returns.

Parameters:
model - the model Map
document - the iText Document to add elements to
writer - the PdfWriter to use
request - in case we need locale etc. Shouldn't look at attributes.
response - in case we need to set cookies. Shouldn't write to it.
Throws:
java.lang.Exception - any exception that occured during document building
See Also:
Document.open(), Document.close()

Spring Framework