pack200(1)                  General Commands Manual                 pack200(1)

       pack200 - JAR Packing tool

       pack200 [ options ] output-file JAR-file

       Options may be in any order. The last option on the command line or in
       a properties file supersedes all previously specified options.

             Command-line options.

             Name of the output file.

             Name of the input file.

       The pack200 tool is a Java application that transforms a JAR file into
       a compressed pack200 file using the Java gzip compressor. The pack200
       files are highly compressed files that can be directly deployed, saving
       bandwidth and reducing download time.

       The pack200 tool uses several options to fine-tune and set the
       compression engine.

   Typical usage:
       % pack200 myarchive.pack.gz myarchive.jar

       In this example, myarchive.pack.gz is produced using the default
       pack200 settings.

       -r --repack

       Produces a JAR file by packing the file myarchive.jar and unpacking it.
       The resulting file can be used as an input to the jarsigner(1) tool.

       % pack200 --repack myarchive-packer.jar myarchive.jar

       % pack200 --repack myarchive.jar

       -g --no-gzip

       Produces a pack200 file. With this option a suitable compressor must be
       used, and the target system must use a corresponding decompresser.

       % pack200 --no-gzip myarchive.pack myarchive.jar

       -G --strip-debug

       Strips attributes used for debugging from the output. These include
       SourceFile, LineNumberTable, LocalVariableTable and
       LocalVariableTypeTable. Removing these attributes reduces the size of
       both downloads and installations but reduces the usefulness of


       Preserve the order of files in the input file; this is the default

       -O --no-keep-file-order

       The packer will reorder and transmit all elements. Additionally, the
       packer may remove JAR directory names. This will reduce the download
       size; however, certain JAR file optimizations, such as indexing, may
       not work correctly.

       -Svalue --segment-limit=value

       The value is the estimated target size N (in bytes) of each archive
       segment. If a single input file requires
       more than N bytes, it will be given its own archive segment. As a
       special case, a value of -1 will produce a single large segment with
       all input files, while a value of 0 will produce one segment for each
       class. Larger archive segments result in less fragmentation and better
       compression, but processing them requires more memory.

       The size of each segment is estimated by counting the size of each
       input file to be transmitted in the segment, along with the size of its
       name and other transmitted properties.

       The default is -1, which means the packer will always create a single
       segment output file. In cases where extremely large output files are
       generated, users are strongly encouraged to use segmenting or break up
       the input file into smaller JARs.

       A 10MB JAR packed without this limit will typically pack about 10%
       smaller, but the packer may require a larger Java heap (about ten times
       the segment limit).

       -Evalue --effort=value

       If the value is set to a single decimal digit, the packer will use the
       indicated amount of effort in compressing the archive. Level 1 may
       produce somewhat larger size and faster compression speed, while level
       9 will take much longer but may produce better compression. The special
       value 0 instructs the packer to copy through the original JAR file
       directly with no compression. The JSR 200 standard requires any
       unpacker to understand this special case as a pass-through of the
       entire archive.

       The default is 5, investing a modest amount of time to produce
       reasonable compression.

       -Hvalue --deflate-hint=value

       Overrides the default, which preserves the input information, but may
       cause the transmitted archive to be larger. The possible values are:


             In either case, the packer will set the deflation hint
             accordingly in the output archive, and will not transmit the
             individual deflation hints of archive elements.

             Preserve deflation hints observed in the input JAR. (This is the

       -mvalue --modification-time=value

       The possible values are:

             The packer will attempt to determine the latest modification
             time, among all the available entries in the original archive, or
             the latest modification time of all the available entries in that
             segment. This single value will be transmitted as part of the
             segment and applied to all the entries in each segment. This can
             marginally decrease the transmitted size of the archive at the
             expense of setting all installed files to a single date.

             Preserves modification times observed in the input JAR. (This is
             the default.)

       -Pfile --pass-file=file

       Indicates that a file should be passed through bytewise with no
       compression. By repeating the option, multiple files may be specified.
       There is no pathname transformation, except that the system file
       separator is replaced by the JAR file separator "/". The resulting file
       names must match exactly as strings with their occurrences in the JAR
       file. If file is a directory name, all files under that directory will
       be passed.

       -Uaction --unknown-attribute=action

       Overrides the default behavior; i.e., the classfile containing the
       unknown attribute will be passed through with the specified action. The
       possible values for actions are:

             The pack200 operation as a whole will fail with a suitable

             The attribute will be dropped. Note: Removing the required VM
             attributes may cause Class Loader failures.

             Upon encountering this attribute, the entire class will be
             transmitted as though it is a resource.

       -Cattribute-name=layout --class-attribute=attribute-name=action
       -Fattribute-name=layout --field-attribute=attribute-name=action
       -Mattribute-name=layout --method-attribute=attribute-name=action
       -Dattribute-name=layout --code-attribute=attribute-name=action

       With the above four options, the attribute layout can be specified for
       a class entity, such as Class attribute, Field attribute, Method
       attribute, and Code attribute. The attribute-name is the name of the
       attribute for which the layout or action is being defined. The possible
       values for action are:

             The layout language is defined in the JSR 200 specification.

          Example: --class-attribute=SourceFile=RUH

             Upon encountering this attribute, the pack200 operation will fail
             with a suitable explanation.

             Upon encountering this attribute, the attribute will be removed
             from the output. Note: removing VM-required attributes may cause
             Class Loader failures.

       Example: --class-attribute=CompilationID=pass will cause the class file
       containing this attribute to be passed through without further action
       by the packer.


       A configuration file, containing Java properties to initialize the
       packer, may be specified on the command line.

       % pack200 -f myarchive.pack.gz myarchive.jar
       % more
       # Generic properties for the packer.
       # This option will cause the files bearing new attributes to
       # be reported as an error rather than passed uncompressed.
       # Change the segment limit to be unlimited.

       -v --verbose

       Outputs minimal messages. Multiple specification of this option will
       output more verbose messages.

       -q --quiet

       Specifies quiet operation with no messages.

       -lfilename --log-file=filename

       Specifies a log file to output messages.

       -? -h --help

       Prints help information about this command.

       -V --version

       Prints version information about this command.


       Passes option to the Java launcher called by pack200. For example,
       -J-Xms48m sets the startup memory to 48 megabytes. Although it does not
       begin with -X, it is not a standard option of pack200. It is a common
       convention for -J to pass options to the underlying VM executing
       applications written in Java.

       The following exit values are returned:

        0 for successful completion;

       >0 if an error occurs.

          o unpack200(1)

          o Java SE Documentation @

          o Java Deployment Guide - Pack200 @

          o jar(1) - Java Archive Tool

          o jarsigner(1) - JAR Signer tool

          o attributes(5) man page

       This command should not be confused with pack(1). They are distinctly
       separate products.

       The Java SE API Specification provided with the JDK is the superseding
       authority, in case of discrepancies.

                                  16 Mar 2012                       pack200(1)