org.springframework.web.servlet.view.document.AbstractPdfStamperView Maven / Gradle / Ivy
/*
* Copyright 2002-2018 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* https://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.springframework.web.servlet.view.document;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.util.Map;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import com.lowagie.text.pdf.PdfReader;
import com.lowagie.text.pdf.PdfStamper;
import org.springframework.util.Assert;
import org.springframework.web.servlet.view.AbstractUrlBasedView;
/**
* Abstract superclass for PDF views that operate on an existing
* document with an AcroForm. Application-specific view classes
* will extend this class to merge the PDF form with model data.
*
* This view implementation uses Bruno Lowagie's
* iText API.
* Known to work with the original iText 2.1.7 as well as its fork
* OpenPDF.
* We strongly recommend OpenPDF since it is actively maintained
* and fixes an important vulnerability for untrusted PDF content.
*
*
Thanks to Bryant Larsen for the suggestion and the original prototype!
*
* @author Juergen Hoeller
* @since 2.5.4
* @see AbstractPdfView
*/
public abstract class AbstractPdfStamperView extends AbstractUrlBasedView {
public AbstractPdfStamperView(){
setContentType("application/pdf");
}
@Override
protected boolean generatesDownloadContent() {
return true;
}
@Override
protected final void renderMergedOutputModel(
Map model, HttpServletRequest request, HttpServletResponse response) throws Exception {
// IE workaround: write into byte array first.
ByteArrayOutputStream baos = createTemporaryOutputStream();
PdfReader reader = readPdfResource();
PdfStamper stamper = new PdfStamper(reader, baos);
mergePdfDocument(model, stamper, request, response);
stamper.close();
// Flush to HTTP response.
writeToResponse(response, baos);
}
/**
* Read the raw PDF resource into an iText PdfReader.
* The default implementation resolve the specified "url" property
* as ApplicationContext resource.
* @return the PdfReader instance
* @throws IOException if resource access failed
* @see #setUrl
*/
protected PdfReader readPdfResource() throws IOException {
String url = getUrl();
Assert.state(url != null, "'url' not set");
return new PdfReader(obtainApplicationContext().getResource(url).getInputStream());
}
/**
* Subclasses must implement this method to merge the PDF form
* with the given model data.
*
This is where you are able to set values on the AcroForm.
* An example of what can be done at this level is:
*
* // get the form from the document
* AcroFields form = stamper.getAcroFields();
*
* // set some values on the form
* form.setField("field1", "value1");
* form.setField("field2", "Vvlue2");
*
* // set the disposition and filename
* response.setHeader("Content-disposition", "attachment; FILENAME=someName.pdf");
* 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.
* @param model the model Map
* @param stamper the PdfStamper instance that will contain the AcroFields.
* You may also customize this PdfStamper instance according to your needs,
* e.g. setting the "formFlattening" property.
* @param request in case we need locale etc. Shouldn't look at attributes.
* @param response in case we need to set cookies. Shouldn't write to it.
* @throws Exception any exception that occurred during document building
*/
protected abstract void mergePdfDocument(Map model, PdfStamper stamper,
HttpServletRequest request, HttpServletResponse response) throws Exception;
}