Question

我在MapReduce中创建了一个wordcount示例，并尝试使用以下命令制作jar文件：

hduseros@MT2012018:/usr/local/hadoop$ jar -cvf playground/wordcount.jar -C playground/classes

但它根本没有运行并给我以下结果：

hduseros@MT2012018:/usr/local/hadoop$ jar -cvf playground/wordcount.jar -C playground/classes
Usage: jar {ctxui}[vfm0Me] [jar-file] [manifest-file] [entry-point] [-C dir] files ...
Options:
    -c  create new archive
    -t  list table of contents for archive
    -x  extract named (or all) files from archive
    -u  update existing archive
    -v  generate verbose output on standard output
    -f  specify archive file name
    -m  include manifest information from specified manifest file
    -e  specify application entry point for stand-alone application 
        bundled into an executable jar file
    -0  store only; use no ZIP compression
    -M  do not create a manifest file for the entries
    -i  generate index information for the specified jar files
    -C  change to the specified directory and include the following file
If any file is a directory then it is processed recursively.
The manifest file name, the archive file name and the entry point name are
specified in the same order as the 'm', 'f' and 'e' flags.

Example 1: to archive two class files into an archive called classes.jar: 
       jar cvf classes.jar Foo.class Bar.class 
Example 2: use an existing manifest file 'mymanifest' and archive all the
           files in the foo/ directory into 'classes.jar': 
       jar cvfm classes.jar mymanifest -C foo/ .

请纠正错误的地方。我已经设置了类路径。我可以运行已经存在但不能生成jar文件的示例。

Answer 1

这可能是因为你没有给它提供从中挑选文件所需的位置。试试这个：

jar -cvf playground/wordcount.jar -C playground/classes .

并包括最后一个点（。）

Answer 2

尝试删除短划线：jar cvf，而不是jar -cvf

Answer 3

尝试执行以下命令：

jar cvf playground/wordcount.jar playground/classes/*.class

另请参阅：Building a JAR File of Interface Classes

Answer 4

-C 选项只是将您的目录更改为您之后给出的参数。您仍然应该在切换到该目录后添加要添加到 jar 文件的文件/目录。

请检查 documentation for jar command。

jar - cvf命令没有运行？

4 个答案: