Spec-Zone .ru
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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.
options
output-file
JAR-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.
% 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 debuggers.
--keep-file-order
Preserve the order of files in the input file; this is the default behavior.
-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:
true
false
keep
-mvalue
--modification-time=value
The possible values are:
latest
keep
-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:
error
pack200
operation as a whole will fail with a
suitable explanation.strip
pass
-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:
some-layout-string
Example: --class-attribute=SourceFile=RUH
error
strip
Example: --class-attribute=CompilationID=pass
will
cause the class file containing this attribute to be passed through
without further action by the packer.
-f pack.properties
--config-file=pack.properties
A configuration file, containing Java properties to initialize the packer, may be specified on the command line.
% pack200 -f pack.properties myarchive.pack.gz
myarchive.jar
% more pack.properties
# Generic properties for the packer.
modification.time=latest
deflate.hint=false
keep.file.order=false
# This option will cause the files bearing new attributes to
# be reported as an error rather than passed uncompressed.
unknown.attribute=error
# Change the segment limit to be unlimited.
segment.limit=-1
-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.
-Joption
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.
jar
- Java Archive
Tooljarsigner
-
JAR Signer toolattributes(5)
man pageThis 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.