Maven Help, mvn is not recognized as an internal/external command

问题

My System variables are:

> set PATH
> %SystemRoot%\system32;%SystemRoot%;%SystemRoot%\System32\Wbem;%SYSTEMROOT%\System32\WindowsPowerShell\v1.0\;C:\Program
> Files\Java\jdk1.8.0_05\bin;M2_HOME=C:\Program Files\Apache Software
> Foundation\apache-maven-3.2.1;M2=C:\Program Files\Apache Software
> Foundation\apache-maven-3.2.1\bin;MAVEN_OPTS=-Xms256m -Xmx512m

and my System Variables are:

C:\Program Files\Java\jre8\bin;C:\Program Files\Apache Software Foundation\apache-maven-3.2.1

EDIT:

Can Someone Just Please tell me how my System Variables are supposed to look like fully? Thanks

Whats Wrong? When i run mvn --version, i get mvn is not recognized as an internal/external command.

回答1:

Your PATH should include directory where mvn.bat is located. According to your question, right now this directory is not included.

Try updating PATH like this:

set PATH [all what is already here];C:\Program Files\Apache Software Foundation\apache-maven-3.2.1\bin

Also, to run Maven from Windows shell, you need JAVA_HOME environment variable. It should point to the place where JRE you want Maven to use is located. Most likely you'll want something like this, depending on exact path where your JRE is:

JAVA_HOME=C:\Program Files\Java\jdk1.8.0_05\jre8

You may need to relogin or even restart Windows to see effect.

回答2:

Your configuration is a bit strange and has some mistakes. Lets do the right way:

First go to your system variable PATH and change it to:

%SystemRoot%\system32;%SystemRoot%;%SystemRoot%\System32\Wbem;%SYSTEMROOT%\System32\WindowsPowerShell\v1.0\;C:\Program Files\Java\jdk1.8.0_05\bin;C:\Program Files\Apache Software Foundation\apache-maven-3.2.1\bin

Create a new variable with the name M2_HOME and with the value C:\Program Files\Apache Software Foundation\apache-maven-3.2.1

And another one with the name MAVEN_OPTS with the value -Xms256m -Xmx512m

This should solve your problem.

UPDATE

To fix the error that you said on the comment just create another variable with the name JAVA_HOME and with the value C:\Program Files\Java\jdk1.8.0_05

来源：https://stackoverflow.com/questions/23701730/maven-help-mvn-is-not-recognized-as-an-internal-external-command