Cannot run program “npm” in directory

问题

When i am traversing the to src/main/app/ folder structure where i have the package.JSON & gruntfile, i am able to run npm install and grunt command. But when i am trying to run the mvn jetty:run and a property file in the root folder of the project when POM file is present, it is throwing error that it cannot run npm install in the folder structure src/main/app/.

This is the exact error:

[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal org.codehaus.mojo:exec-maven-plugin:1.2.1:exec (n
pminstall) on project my-abc-web: Command execution failed. Cannot
 run program "npm" (in directory "C:\Users\Achyut_J01\Documents\GitHub\infras\my-abc\my-abc-web\src\main\app"): CreatePro
cess error=2, The system cannot find the file specified -> [Help 1]

It's a Windows Machine.

回答1:

Evidently you are on a Windows system. npm is a batch file and not an executable. There are issues running a batch file from maven exec plugin. You may want to explore the workaround suggested in the link, like

deconstruct the .bat script into its actual commands
use cmd.exe and pass node as parameter - refer to this.

回答2:

I used this workaround to have a cross-platform Maven build : declare the npm executable name as a Maven variable, and use Maven filters to modify this executable name when running on Windows.

It can work the same for Grunt, Bower etc.

This workaround is not necessary any more if you use exec-maven-plugin >=1.6.0 (thanks Manmay for the information in the comments): it was a bug of this plugin (see https://github.com/mojohaus/exec-maven-plugin/issues/42), that has been fixed in 1.6.0 (see https://github.com/mojohaus/exec-maven-plugin/pull/46)

<properties>
    <npm.executable>npm</npm.executable>
</properties>

(...)

<build>
    <plugins>
        (...)
        <plugin>
            <groupId>org.codehaus.mojo</groupId>
            <artifactId>exec-maven-plugin</artifactId>
            <version>1.5.0</version>
            <executions>
                <execution>
                    <id>exec-npm</id>
                    <phase>process-resources</phase>
                    <configuration>
                        <executable>${npm.executable}</executable>
                        <arguments>
                            <argument>install</argument>
                        </arguments>
                    </configuration>
                    <goals>
                        <goal>exec</goal>
                    </goals>
                </execution>
            </executions>
        </plugin>
        (...)
    </plugins>
</build>
<profiles>
    <profile>
        <id>platform-windows</id>
        <activation>
            <os>
                <family>windows</family>
            </os>
        </activation>
        <properties>
            <!-- Override the executable names for Windows -->
            <npm.executable>npm.cmd</npm.executable>
            <grunt.executable>grunt.cmd</grunt.executable>
            <bower.executable>bower.cmd</bower.executable>
        </properties>
    </profile>
</profiles>

回答3:

In Windows Platform, use npm.cmd to replace npm

回答4:

See the link for details: https://stackoverflow.com/a/48184182/4282901

In the directory where node is installed rename the batch file so that the existing npm.cmd file is picked. See screenshot below:

This method is preferable if you build the projects targeting linux and windows both. Moreover, also if the no. of pom files is also large.

来源：https://stackoverflow.com/questions/22708255/cannot-run-program-npm-in-directory

标签

node.js

maven

gruntjs