OutOfMemoryError during the pdf merge
- by Vijay
the below code merges the pdf files and returns the combined pdf data. while this code runs, i try to combine the 100 files with each file approximately around 500kb, i get outofmemory error in the line document.close();. this code runs in the web environment, is the memory available to webspehere server is the problem? i read in an article to use freeReader method, but i cannot get how to use it my scenario.
protected ByteArrayOutputStream joinPDFs(List<InputStream> pdfStreams,
boolean paginate) {
Document document = new Document();
ByteArrayOutputStream mergedPdfStream = new ByteArrayOutputStream();
try {
//List<InputStream> pdfs = pdfStreams;
List<PdfReader> readers = new ArrayList<PdfReader>();
int totalPages = 0;
//Iterator<InputStream> iteratorPDFs = pdfs.iterator();
Iterator<InputStream> iteratorPDFs = pdfStreams.iterator();
// Create Readers for the pdfs.
while (iteratorPDFs.hasNext()) {
InputStream pdf = iteratorPDFs.next();
if (pdf == null)
continue;
PdfReader pdfReader = new PdfReader(pdf);
readers.add(pdfReader);
totalPages += pdfReader.getNumberOfPages();
}
//clear this
pdfStreams = null;
//WeakReference ref = new WeakReference(pdfs);
//ref.clear();
// Create a writer for the outputstream
PdfWriter writer = PdfWriter.getInstance(document, mergedPdfStream);
writer.setFullCompression();
document.open();
BaseFont bf = BaseFont.createFont(BaseFont.HELVETICA,
BaseFont.CP1252, BaseFont.NOT_EMBEDDED);
PdfContentByte cb = writer.getDirectContent(); // Holds the PDF
// data
PdfImportedPage page;
int currentPageNumber = 0;
int pageOfCurrentReaderPDF = 0;
Iterator<PdfReader> iteratorPDFReader = readers.iterator();
// Loop through the PDF files and add to the output.
while (iteratorPDFReader.hasNext()) {
PdfReader pdfReader = iteratorPDFReader.next();
// Create a new page in the target for each source page.
while (pageOfCurrentReaderPDF < pdfReader.getNumberOfPages()) {
pageOfCurrentReaderPDF++;
document.setPageSize(pdfReader
.getPageSizeWithRotation(pageOfCurrentReaderPDF));
document.newPage();
// pageOfCurrentReaderPDF++;
currentPageNumber++;
page = writer.getImportedPage(pdfReader,
pageOfCurrentReaderPDF);
cb.addTemplate(page, 0, 0);
// Code for pagination.
if (paginate) {
cb.beginText();
cb.setFontAndSize(bf, 9);
cb.showTextAligned(PdfContentByte.ALIGN_CENTER, ""
+ currentPageNumber + " of " + totalPages, 520,
5, 0);
cb.endText();
}
}
pageOfCurrentReaderPDF = 0;
System.out.println("now the size is: "+pdfReader.getFileLength());
}
mergedPdfStream.flush();
document.close();
mergedPdfStream.close();
return mergedPdfStream;
} catch (Exception e) {
e.printStackTrace();
} finally {
if (document.isOpen())
document.close();
try {
if (mergedPdfStream != null)
mergedPdfStream.close();
} catch (IOException ioe) {
ioe.printStackTrace();
}
}
return mergedPdfStream;
}
Thanks
V
