PJX specifically included significantly faster reading and writing of PDF documents, thread safety, "on demand" reading and parsing of PDF objects which greatly reduces memory usage and processing time, incremental update support to enable fast modification of PDF documents, reading PDF documents from either disk or memory, thorough documentation of the class library interface, support for J2SE collection classes and NIO, access to form/field objects, rudimentary support for insertion of images and watermarks, appending of large documents, and design patterns for recursive processing of PDF objects.
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