Java library (8, 11, 17, 21 etc) for working with "native" resources on the JVM. Utilities for finding & extracting OS and hardware architecture dependent files, executables, and libraries (e.g. including libraries as resources in JARs), as well as utilities for detecting installed JDKs, or calculating the "targets" of native compilation.
This is a battle-tested library w/ extensive test coverage and automated CI across various operating systems, versions, and architectures.
Includes the following features:
- JNE class: helps to find, extract, and load OS, ABI, and hardware architecture dependent files, executables, and libraries
- NativeTarget class: helps to compile native code by determining various "targets" for Rust, C/C++, or for CI frameworks
- JavaHome, JavaHomes classes: helps to detect JDKs installed on the local system, as well as versions, distribution, JDK vs. JRE, etc.
- Support for Linux, Windows, MacOS, FreeBSD, OpenBSD operating systems
- Support for x64, x32, arm64, armhf, armel, riscv64 hardware architecture
- Support for GNU & MUSL abis
- Support for multiple operating systems and architectures so that a single jar dependency can support them all.
- Support for finding executables (e.g. cat or cat.exe)
- Support for finding libraries (e.g. sample.dll/libsample.dylib/libsample.so)
- Support for finding generic files (e.g. movie.swf)
- Use a one-time temporary directory for extracted executables (thus same apps running multiple instances get their own executable copy)
- Specify a directory to extract executables to (useful for single instance daemons).
- Specify if executables should be deleted on VM exit. If disabled and an extracted directory is specified, then a "hash" is calculated for an extracted executable so that if the next run of the app has a dependency change then the latest executable will be used.
- Optional fallback to x86 executables on x64 platforms where an x64-specific executable is not found/included. Useful in the case where an x86 executable is good for either architecture and you want to save space by not including both versions in your JAR.
- Utility classes for double-locking, safe loading of libraries.
Project by Fizzed, Inc. (Follow on Twitter: @fizzed_inc)
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JNE can helps with finding, extracting, and using os and architecture dependent files (executables, libraries, and/or other files) that are packaged as resources within jar files. Extensive support and testing for operating system, libc (e.g. glibc vs. musl), and hardware architecture detection.
Allows them to be easily included as part of a Java application and intelligently extracted for use at runtime. This library makes it easy to build your own custom "bin" directory based on the runtime operating system and architecture. You can package .exe and .dll/.so resources within jars and then use something like maven for dependency management.
Here is how it works. At runtime, Java let's you find resources in directories and/or jars (if they are included on the classpath). Let's say you wanted to load at runtime a shared object (.dll, .so, .dylib) that was packaged inside a .jar
JNE.loadLibrary("mylib");
The library would search for the resource using the following resource path
/jne/<os>/<arch>/<lib>
Or let's say you wanted to call an external "cat" executable. With a properly packaged resource on the classpath this executable can found with
File catExeFile = JNE.findExecutable("cat");
If found the resource would be intelligently extracted to a temporary directory so it can be executed.
/tmp/1394227238992-0/cat
Where "os" would be something such as "windows", "macos", or "linux" and "arch" could be "x32" or "x64". If we were running on Linux with a 64-bit operating system then the library would search for "/jne/linux/x64/cat". If found and contained within a jar file then this executable would be extracted to either a specific or temporary directory and returned as a File object. This File object can then be included as the first argument to a Process or ProcessBuilder object. There are other options as well (e.g. fallback to x86 resources on x64 platforms) so please see features below.
All popular operating systems are supported, along with special care for MUSL-based operating systems such as Alpine Linux.
| OS | Description |
|---|---|
| linux | |
| linux_musl | Such as alpine linux |
| macos | Also supports osx in resource path |
| windows | |
| freebsd | |
| openbsd | |
| solaris |
Since this library targets finding or loading libraries for use within a JVM, the supported hardware architectures match what you'd typically find JDK distributors call their architectures.
| Arch | Description | Docker |
|---|---|---|
| x32 | 32-bit i386, i486, i686, etc. | i386/debian |
| x64 | 64-bit. Can also use x86_64, amd64 in resource path | |
| armel | 32-bit armv4, armv5, armv6 w/ soft float support. E.g. Raspberry Pi 1 | arm32v5/debian |
| armhf | 32-bit armv7 w/ hard float support. E.g. Raspberry Pi 2 | arm32v7/debian |
| arm64 | 64-bit. Can also use aarch64 in resource path. E.g. Mac M1, Raspberry 3, 4 | arm64v8/ubuntu |
| mips64le | 64-bit mips | mips64le/debian |
| riscv64 | 64-bit risc-v | riscv64/ubuntu |
| s390x | s390x/debian | |
| ppc64le | ppc64le/debian |
Published to maven central use the following
<dependency>
<groupId>com.fizzed</groupId>
<artifactId>jne</artifactId>
<version>VERSION</version>
</dependency>To safely load a library one time at application startup
/**
* Custom safe run once loading of native libs.
*/
public class CustomLoader {
static private final MemoizedRunner loader = new MemoizedRunner();
static public void loadLibrary() {
loader.once(() -> {
JNE.loadLibrary("jtokyocabinet");
});
}
}To find a JDK 21 on your local system with a specific distribution:
final JavaHome jdk21 = new JavaHomeFinder()
.jdk()
.version(21)
.preferredDistributions(JavaDistribution.ZULU)
.find();To run a demo of a "cat" executable
mvn -e test-compile exec:java -Dexec.classpathScope="test" -Dexec.mainClass="com.fizzed.jne.JneDemo"
With overridden extract dir via system property:
mvn -e test-compile exec:java -Dexec.classpathScope="test" -Dexec.mainClass="com.fizzed.jne.JneDemo" -Djne.extract.dir="target/jne"
If using Maven then by default it will include everything in src/main/resources
in a jar. Let's say you wanted to package a "cat" executable for various platforms.
You can easily include these for use with JNE by putting them at
src/main/resources/jne/windows/x32/cat.exe
src/main/resources/jne/windows/x64/cat.exe
src/main/resources/jne/macos/x32/cat
src/main/resources/jne/macos/x64/cat
src/main/resources/jne/linux/x32/cat
src/main/resources/jne/linux/x64/cat
src/main/resources/jne/linux_musl/x64/cat
src/main/resources/jne/generic-resource.txt
To find and extract these resources for use in your app
File exeFile = JNE.findLibrary("cat", options);
You'll probably want to package your executables as statically compiled (it does not rely on external DLLs / shared objects to be available on the runtime system). However, since this library does essentially build a "bin" directory by extracting resources, you could find all dependencies first before trying to execute it. For example:
File libFile = JNE.findLibrary("mylib", options);
File exeFile = JNE.findExecutable("myapp", options);
If this was run on Linux with the extractDir as null (which then uses a temp dir) you would have the following example result:
/tmp/1394227238992-0/mylib.so
/tmp/1394227238992-0/myapp
To extract a generic resource
File resourceFile = JNE.findFile("generic-resource.txt", options);
You can use an Ubuntu x86_64 host to test a wide variety of hardware architectures and operating systems. For more information on how this works, please visit https://github.com/fizzed/blaze-buildx#multiple-architecture-containers
You can test this library on a wide variety of operating systems and architectures
java -jar blaze.jar test
Copyright (C) 2015+ Fizzed, Inc.
This work is licensed under the Apache License, Version 2.0. See LICENSE for details.