Add sigar library to build.gradle in java project - eclipse

Question

I am using Sigar library to find system level resource usage in my java application. I added Sigar to my build.gradle (as suggested at http://mvnrepository.com/artifact/org.fusesource/sigar/1.6.4) as shown below:
// Apply the java plugin to add support for Java
apply plugin: 'java'
// In this section you declare where to find the dependencies of your project
repositories {
// Use 'jcenter' for resolving your dependencies.
// You can declare any Maven/Ivy/file repository here.
maven {
url "https://plugins.gradle.org/m2/"
}
jcenter()
mavenCentral()
}
// In this section you declare the dependencies for your production and test code
dependencies {
// The production code uses the SLF4J logging API at compile time
compile 'org.fusesource:sigar:1.6.4'
// Declare the dependency for your favourite test framework you want to use in your tests.
// TestNG is also supported by the Gradle Test task. Just change the
// testCompile dependency to testCompile 'org.testng:testng:6.8.1' and add
// 'test.useTestNG()' to your build script.
testCompile 'junit:junit:4.12'
}
When I try to run my project I get following error:
Exception in thread "main" java.lang.UnsatisfiedLinkError: org.hyperic.sigar.Mem.gather(Lorg/hyperic/sigar/Sigar;)V
at org.hyperic.sigar.Mem.gather(Native Method)
at org.hyperic.sigar.Mem.fetch(Mem.java:30)
at org.hyperic.sigar.Sigar.getMem(Sigar.java:304)
at SystemResources.SystemMemory.getSystemMemory(SystemMemory.java:37)
at SystemResources.SystemResources.getSystemResources(SystemResources.java:25)
at Test.Driver.main(Driver.java:31)
After searching on Stackoverflow and other places, I know there are .dll and .so files whose path has to be modified. But when I add my library using gradle I am not able to change the path of my native library (in Properties->Java Build path->Library-> -> Native Library Path). Also i tried using
-Djava.library.path="./sigar-bin/lib" ${build_files}
and
-Djava.library.path="./lib" ${build_files}
in my environment variable in run configuration but it doesn't help.
I need to use gradle file to import sigar and that works perfectly. But how do I reference those .dll and .so files for my project to work?
After #Brian's comments this is what I am trying for build.gradle:
// Apply the java plugin to add support for Java
apply plugin: 'java'
apply plugin: 'eclipse'
// In this section you declare where to find the dependencies of your project
repositories {
// Use 'jcenter' for resolving your dependencies.
// You can declare any Maven/Ivy/file repository here.
maven {
url "https://plugins.gradle.org/m2/"
}
jcenter()
mavenCentral()
}
//Setting extra information for the project in key value pair
//Key - nativeLibsDir, Value - $buildDir/libs/natives
project.ext.set('nativeLibsDir', "${buildDir}/libs/natives")
configurations {
nativeBundle
}
// In this section you declare the dependencies for your production and test code
dependencies {
// The production code uses the SLF4J logging API at compile time
compile 'org.slf4j:slf4j-api:1.7.13'
compile 'org.fusesource:sigar:1.6.4'
runtime 'org.fusesource:sigar:1.6.4'
nativeBundle 'org.fusesource:sigar:1.6.4:native'
// Declare the dependency for your favourite test framework you want to use in your tests.
// TestNG is also supported by the Gradle Test task. Just change the
// testCompile dependency to testCompile 'org.testng:testng:6.8.1' and add
// 'test.useTestNG()' to your build script.
testCompile 'junit:junit:4.12'
}
jar {
manifest {
attributes 'Main-Class': 'Test.Driver'
}
//baseName = project.name + '-all'
//from { configurations.compile.collect { it.isDirectory() ? it : zipTree(it) } }
//with jar
}
task extractNativeBundle(type: Sync) {
from {
configurations.nativeBundle.collect { zipTree(it) }
}
into file(project.nativeLibsDir)
}
test {
dependsOn extractNativeBundle
systemProperty "java.library.path", project.nativeLibsDir
}
Even after this I get following error:
Error: A JNI error has occurred, please check your installation and try again
Exception in thread "main" java.lang.NoClassDefFoundError: org/hyperic/sigar/SigarException
at java.lang.Class.getDeclaredMethods0(Native Method)
at java.lang.Class.privateGetDeclaredMethods(Class.java:2701)
at java.lang.Class.privateGetMethodRecursive(Class.java:3048)
at java.lang.Class.getMethod0(Class.java:3018)
at java.lang.Class.getMethod(Class.java:1784)
at sun.launcher.LauncherHelper.validateMainClass(LauncherHelper.java:544)
at sun.launcher.LauncherHelper.checkAndLoadMain(LauncherHelper.java:526)
Caused by: java.lang.ClassNotFoundException: org.hyperic.sigar.SigarException
at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:331)
at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
... 7 more