Support mvn spring-boot:run with classpaths that exceeds Windows' length limits

[pneuschwander]

Hi there, we use Spring Boot Version 2.1.5.RELEASE + maven 3.6.0 on a windows 10 machine to develop a spring webmvc application.

When invoking mvn spring-boot:run the following exception occurs:

Caused by: java.io.IOException: CreateProcess error=206, The filename or extension is too long
    at java.lang.ProcessImpl.create (Native Method)
    at java.lang.ProcessImpl.<init> (ProcessImpl.java:420)
    at java.lang.ProcessImpl.start (ProcessImpl.java:151)
    at java.lang.ProcessBuilder.start (ProcessBuilder.java:1107)
    at java.lang.ProcessBuilder.start (ProcessBuilder.java:1071)
    at org.springframework.boot.loader.tools.RunProcess.run (RunProcess.java:81)
    at org.springframework.boot.maven.RunMojo.forkJvm (RunMojo.java:103)

Problem: Our classpath is too long as we have many dependencies.

A feature/fix to shorten the command line in such cases (e.g. use of temp argFile) would be awesome.

[philwebb]

Out of interest, have you tried this: https://www.howtogeek.com/266621/how-to-make-windows-10-accept-file-paths-over-260-characters/

[pneuschwander]

@philwebb Thank you for that hint. I tried it but sadly it does not work in this case. Still getting the same exception :-/

Maybe it is not about the filepath length limit.
java.lang.ProcessImpl.create javadoc states "Create a process using the win32 function CreateProcess."
Found these information sources:

• https://devblogs.microsoft.com/oldnewthing/20031210-00/?p=41553
• https://docs.microsoft.com/en-us/windows/win32/api/processthreadsapi/nf-processthreadsapi-createprocessa

stating that the command line length is limited to 32767 characters.
Our classpath exceeds this limit as there are too many entries...

[philwebb]

Thanks for trying, we'll have to try and investigate what options we have.

[wilkinsona]

I believe ./gradlew bootRun will also be affected.

There's some interesting discussion of this in a couple of Gradle issues: gradle/gradle#1989 and gradle/gradle#10114. A pathing jar (jar that's used purely to declare the classpath via its manifest) is the most common solution but those issues point out some notable downsides. The latter of the two is tracking a fix for the problem that would mean we don't need to do anything on the Gradle side when using Gradle 6+.

[koosty]

I have the same issue with 2.2.0.RELEASE but works fine with 2.1.9.RELEASE.
I'm using Windows 10 and tested both with Maven 3.5.0 and 3.6.0

[rampem]

I have similar issue with 2.2.0.RELEASE and 2.2.1.RELEASE while 2.1.10.RELEASE works fine. It could be the classpath which in my case is around 37500 characters.

[bjornmagnusson]

We are also experiencing this issue when upgrading to 2.2.0.RELEASE.
Worked fine in 2.1.2.RELEASE

Discovered our classpath was roughly 38000 characters long

The work-around we took was moving the USER_HOME/.m2/repository to C:/m2