Pack200.Packer The packer engine applies various transformations to the input JAR file, making the pack stream highly compressible by a compressor such as gzip or zip. 
Pack200.Unpacker The unpacker engine converts the packed stream to a JAR file. 


Attributes The Attributes class maps Manifest attribute names to associated string values. 
Attributes.Name The Attributes.Name class represents an attribute name stored in this Map. 
JarEntry This class is used to represent a JAR file entry. 
JarFile The JarFile class is used to read the contents of a jar file from any file that can be opened with
JarInputStream The JarInputStream class is used to read the contents of a JAR file from any input stream. 
JarOutputStream The JarOutputStream class is used to write the contents of a JAR file to any output stream. 
Manifest The Manifest class is used to maintain Manifest entry names and their associated Attributes. 
Pack200 Transforms a JAR file to or from a packed stream in Pack200 format. 


JarException Signals that an error of some sort has occurred while reading from or writing to a JAR file.