A poor man's masquerade of the Java Process API pretending to be a low-overhead, non-blocking I/O, external Process execution implementation for Java. It is most certainly not a replacement for
java.lang.ProcessBuilderandjava.lang.Process, instead hiding them behind a more convenient API.
This library is based on Brett Wooldridge's NuProcess library and provides the exact same API while not relying on any sophisticated mechanisms to start and control external processes. It's intended to be used as a drop-in replacement for NuProcess in environments where JNA cannot be used (e.g. GraalVM Native Image).
To keep a lid on the memory impact this library utilizes virtual threads which makes this library incompatible with Java runtimes below version 21.
However, this implementation is not able to reduce the RAM required for the initial
start of external processes because vfork() cannot be utilized without crossing over
into JNI/JNA territory.
Processing the standard out of launched processes is slightly different from the original library because Java doesn't eagerly read the standard out if it cannot fill its buffer or hit EOF. The same applies to the standard error stream.
- JDK 21
I copied over the files describing the public interface and all applicable tests from the original library. Surgical adjustments to the tests were made to reflect the changed runtime behavior regarding standard out processing.
The library is available in the Central Repository.
repositories {
mavenCentral()
}
dependencies {
implementation("io.v47:nuprocess-shim:2.0.4")
}Make sure to exclude the original NuProcess artifact from your dependencies:
com.zaxxer:nuprocess (Sorry, Brett!)
Just refer to Brett Wooldridge's README
You can read Brett's original JavaDoc here as it applies 100% to this library.
The settings as described in Brett's readme have no effect when using this library.
Incidentally, because this library is just a wrapper around the Java Process APIs, no additional limitations apply.
If you want to contribute, I recommend you head on over to the NuProcess repository and
contribute there. This library only exists as a stop-gap measure until JNA becomes available
for GraalVM Native Image, after which it will be discontinued.
But if you still want to contribute: Knock yourself out and create a pull request!
Before creating a pull request make sure you have all the rights to the contributed material or have permission from the original creators to publish it in this fashion.
Furthermore, by creating a pull request you agree to provide the contributed material under the terms of the BSD 3-Clause Clear License.
All Java code taken from NuProcess remains available under the Apache License Version 2 and
the original creators retain their copyright.
All subsequent changes, entirely new code, and any artifacts based on this library are licensed and distributed under the BSD 3-Clause Clear License.