http://xmlgraphics.apache.org/fop/: Apache FOP (Formatting Objects Processor) is the world's first print formatter driven by XSL formatting objects (XSL-FO) and the world's first output independent formatter. It is a Java application that reads a formatting object (FO) tree and renders the resulting pages to a specified output. Output formats currently supported include PDF, PCL, PS, AFP, TIFF, PNG, SVG, XML (area tree representation), Print, AWT and TXT. The primary output target is PDF. (Apache Software Foundation) 
public interface org.apache.fop.pdf.PDFEncryption
  minor version: 0
  major version: 59
  flags: flags: (0x0601) ACC_PUBLIC, ACC_INTERFACE, ACC_ABSTRACT
  this_class: org.apache.fop.pdf.PDFEncryption
  super_class: java.lang.Object
{
  public abstract void applyFilter(org.apache.fop.pdf.AbstractPDFStream);
    descriptor: (Lorg/apache/fop/pdf/AbstractPDFStream;)V
    flags: (0x0401) ACC_PUBLIC, ACC_ABSTRACT
    MethodParameters:
        Name  Flags
      stream  

  public abstract byte[] encrypt(byte[], org.apache.fop.pdf.PDFObject);
    descriptor: ([BLorg/apache/fop/pdf/PDFObject;)[B
    flags: (0x0401) ACC_PUBLIC, ACC_ABSTRACT
    MethodParameters:
        Name  Flags
      data    
      refObj  

  public abstract java.lang.String getTrailerEntry();
    descriptor: ()Ljava/lang/String;
    flags: (0x0401) ACC_PUBLIC, ACC_ABSTRACT

  public abstract org.apache.fop.pdf.Version getPDFVersion();
    descriptor: ()Lorg/apache/fop/pdf/Version;
    flags: (0x0401) ACC_PUBLIC, ACC_ABSTRACT
}
SourceFile: "PDFEncryption.java"