我正在遵循http://openjdk.java.net/projects/jigsaw/quick-start上的 Java 9 Jigsaw 早期访问版本快速入门指南中的步骤
➜ tmp java --version
java 9-ea
Java(TM) SE Runtime Environment (build 9-ea+172)
Java HotSpot(TM) 64-Bit Server VM (build 9-ea+172, mixed mode)
jar 命令是从正确的 Java 9 目录中提取的。
➜ tmp which jar
/Library/Java/JavaVirtualMachines/jdk-9.jdk/Contents/Home/bin/jar
快速入门指南中的步骤之一说要运行带有选项的 jar 命令，--print-module-descriptor但是当我尝试收到以下错误消息时。
➜ tmp jar --print-module-descriptor --file=mlib/org.astro@1.0.jar
unrecognized option : --print-module-descriptor
Try `jar --help' for more information.
看起来这个选项在最新的抢先体验版本中不存在，是被删除还是移到了其他地方？jar --help下面输出供参考
➜ tmp jar --help
Usage: jar [OPTION...] [ [--release VERSION] [-C dir] files] ...
jar creates an archive for classes and resources, and can manipulate or
restore individual classes or resources from an archive.
Examples:
# Create an archive called classes.jar with two class files:
jar --create --file classes.jar Foo.class Bar.class
# Create an archive using an existing manifest, with all the files in foo/:
jar --create --file classes.jar --manifest mymanifest -C foo/ .
# Create a modular jar archive, where the module descriptor is located in
# classes/module-info.class:
jar --create --file foo.jar --main-class com.foo.Main --module-version 1.0
-C foo/ classes resources
# Update an existing non-modular jar to a modular jar:
jar --update --file foo.jar --main-class com.foo.Main --module-version 1.0
-C foo/ module-info.class
# Create a multi-release jar, placing some files in the META-INF/versions/9 directory:
jar --create --file mr.jar -C foo classes --release 9 -C foo9 classes
To shorten or simplify the jar command, you can specify arguments in a separate
text file and pass it to the jar command with the at sign (@) as a prefix.
Examples:
# Read additional options and list of class files from the file classes.list
jar --create --file my.jar @classes.list
Main operation mode:
-c, --create Create the archive
-i, --generate-index=FILE Generate index information for the specified jar
archives
-t, --list List the table of contents for the archive
-u, --update Update an existing jar archive
-x, --extract Extract named (or all) files from the archive
-d, --describe-module Print the module descriptor, or automatic module name
Operation modifiers valid in any mode:
-C DIR Change to the specified directory and include the
following file
-f, --file=FILE The archive file name. When omitted, either stdin or
stdout is used based on the operation
--release VERSION Places all following files in a versioned directory
of the jar (i.e. META-INF/versions/VERSION/)
-v, --verbose Generate verbose output on standard output
Operation modifiers valid only in create and update mode:
-e, --main-class=CLASSNAME The application entry point for stand-alone
applications bundled into a modular, or executable,
jar archive
-m, --manifest=FILE Include the manifest information from the given
manifest file
-M, --no-manifest Do not create a manifest file for the entries
--module-version=VERSION The module version, when creating a modular
jar, or updating a non-modular jar
--hash-modules=PATTERN Compute and record the hashes of modules
matched by the given pattern and that depend upon
directly or indirectly on a modular jar being
created or a non-modular jar being updated
-p, --module-path Location of module dependence for generating
the hash
Operation modifiers valid only in create, update, and generate-index mode:
-0, --no-compress Store only; use no ZIP compression
Other options:
-h, --help[:compat] Give this, or optionally the compatibility, help
--help-extra Give help on extra options
--version Print program version
An archive is a modular jar if a module descriptor, 'module-info.class', is
located in the root of the given directories, or the root of the jar archive
itself. The following operations are only valid when creating a modular jar,
or updating an existing non-modular jar: '--module-version',
'--hash-modules', and '--module-path'.
Mandatory or optional arguments to long options are also mandatory or optional
for any corresponding short options.