Question

我想使用java命令，所以我在互联网上搜索了很多。我发现的是创建一个名为PATH和值为%PATH%;C:\Program Files\Java\jre7\bin的新用户变量。重新启动后，我在cmd：java中写道，它显示：

Usage: java [-options] class [args...]
       (to execute a class)


or  java [-options] -jar jarfile [args...]
           (to execute a jar file)
where options include:
    -d32          use a 32-bit data model if available
    -d64          use a 64-bit data model if available
    -server       to select the "server" VM
    -hotspot      is a synonym for the "server" VM  [deprecated]
                  The default VM is server.

-cp <class search path of directories and zip/jar files>
-classpath <class search path of directories and zip/jar files>
              A ; separated list of directories, JAR archives,
              and ZIP archives to search for class files.
-D<name>=<value>
              set a system property
-verbose:[class|gc|jni]
              enable verbose output
-version      print product version and exit
-version:<value>
              require the specified version to run
-showversion  print product version and continue
-jre-restrict-search | -no-jre-restrict-search
              include/exclude user private JREs in the version search
-? -help      print this help message
-X            print help on non-standard options
-ea[:<packagename>...|:<classname>]
-enableassertions[:<packagename>...|:<classname>]
              enable assertions with specified granularity
-da[:<packagename>...|:<classname>]
-disableassertions[:<packagename>...|:<classname>]
              disable assertions with specified granularity
-esa | -enablesystemassertions
              enable system assertions
-dsa | -disablesystemassertions
              disable system assertions
-agentlib:<libname>[=<options>]
              load native agent library <libname>, e.g. -agentlib:hprof
              see also, -agentlib:jdwp=help and -agentlib:hprof=help
-agentpath:<pathname>[=<options>]
              load native agent library by full pathname
-javaagent:<jarpath>[=<options>]
              load Java programming language agent, see java.lang.instrument

-splash:<imagepath>
                  show splash screen with specified image
See http://www.oracle.com/technetwork/java/javase/documentation/index.html for m
ore details.

然后我输入cmd：jar并显示：

'jar' is not recognized as an internal or external command,
operable program or batch file.

为什么它识别出第一个命令而不识别第二个命令？

我的操作系统是Windows 8 64位。

Answer 1

jar.exe是JDK而不是JRE的一部分。指向JDK 7的路径。

只需转到路径C:\Program Files\Java\jre7\bin并搜索jar.exe即可。你永远不会在那里找到它。

第一条评论java运行正常，因为JDK和JRE中都存在java.exe。

Answer 2

因为jar命令随JDK一起提供，而不是与JRE一起提供。安装JDK并将其添加到PATH。

正确使用jar命令

2 个答案: