Open a PDF in Java

To open a PDF document.

// open document from the filesystem
PDFDoc doc = new PDFDoc(filename);

// optionally read a PDF document from a stream
MappedFile file = new MappedFile(filename);
PDFDoc doc_stream = new PDFDoc(file);

// or pass-in a memory buffer
long file_sz = file.fileSize();
FilterReader file_reader = new FilterReader(file);
byte[] mem = new byte[(int) file_sz];
long bytes_read = file_reader.read(mem);
PDFDoc doc_mem = new PDFDoc(mem, file_sz);

// load from a URL
URL url = new URL("https://myserver.com/myfile.pdf");
PDFDoc doc = new PDFDoc(url.openStream(), url.getContentLength());

Read & write a PDF file from/to memory buffer
Full source code which illustrates how to read/write a PDF document from/to memory buffer. This is useful for applications that work with dynamic PDF documents that don't need to be saved/read from a disk.

The PDFDoc constructor creates a PDF document from scratch:

PDFDoc doc = new PDFDoc();

A newly-created document does not yet contain any pages. See the accessing pages section for details on creating new pages and working with existing pages.

Using Apryse SDK, you can open a document from a serialized file, from a memory buffer, or from a Filter stream.

To open an existing PDF document from a file, specify its file path in the PDFDoc constructor:

PDFDoc doc = new PDFDoc(filename);

Here's how to open an existing PDF document from a memory buffer:

MappedFile file = new MappedFile(filename);
long file_sz = file.fileSize();
FilterReader file_reader = new FilterReader(file);
byte[] mem = new byte[(int) file_sz];
long bytes_read = file_reader.read(mem);
PDFDoc doc_mem = new PDFDoc(mem, file_sz);

It's also easy to open a PDF document from a MemoryFilter or a custom Filter .

After creating a PDFDoc object, it's good practice to call InitSecurityHandler() on it. If the document is encrypted, calling the method will decrypt it. If the document is not encrypted, calling the method is harmless.

PDFDoc doc = new PDFDoc(filename);
if (!doc.initSecurityHandler())
{
  println("Document authentication error...");
  return;
}