I'm currently developing on OS X and trying to load the librxtxSerial.jnilib with System.load(), which just doesn't work and always results in
java.lang.UnsatisfiedLinkError: no rxtxSerial in java.library.path thrown while loading gnu.io.RXTXCommDriver
When I place the lib in /Library/Java/Extensions everything works fine.
I have double checked paths and everything, but it just won't work with System.load when I remove the lib from /Library/Java/Extensions.
I want to bundle the jnilib with a distributable jar, that's why I want to load it programmatically.
Does anybody have an idea?
if you have this:
root:
main.jar
libjni.jnilib
And you run your code at the root directory, using command like:
java -jar main.jar
In this case, your loading code should be like:
System.load("libjni.jnilib");
But bot System.loadLibrary(), load is safer than loadLibrary.
It's recommended to pass the absolute path of your jni library to System.load.
I used something like this in my project:
/**
* To load the JNI library
* Created by ice1000 on 2017/1/6.
*
* #author ice1000
*/
#SuppressWarnings("WeakerAccess")
public final class Loader {
public final static String JNI_LIB_NAME;
private static boolean loaded = false;
/*
* maybe it's already loaded, so there should be a check
*/
static {
JNI_LIB_NAME = "libjni";
loadJni();
}
#NotNull
#Contract(pure = true)
private static String libraryName(#NonNls #NotNull String libName) {
String ___ = System.getProperty("os.name");
String fileName;
if (___.contains("Linux"))
fileName = libName + ".so";
else if (___.contains("Windows"))
fileName = libName + ".dll";
else // if (___.get("OSX"))
fileName = libName + ".dylib";
// else fileName = libName;
return new File(fileName).getAbsolutePath();
}
public static void loadJni() {
if (!loaded) {
System.load(libraryName(JNI_LIB_NAME));
loaded = true;
}
}
}
here's my working directory:
root:
javaClasses.jar
libjni.dll
libjni.so
libjni.dylib
Hope this can help you.
Make sure to put your library on LD_LIBRARY_PATH.
Take a look here for lots of JNI related samples written for macOS/Linux.
http://jnicookbook.owsiak.org
I suggest to start with supper simple Hello world app:
http://jnicookbook.owsiak.org/recipe-No-001/
You can take a look there how to develop with JNI for macOS using standard tools.
Hope this helps. Have fun with JNI.
Related
I wish to do what the title says.
Part Solution:
For example in Windows you can use the code below to open a file in the default explorer and highlight it.
(although it needs modification for files containing spaces):
/**
* Opens the file with the System default file explorer.
*
* #param path the path
*/
public static void openFileLocation(String path) {
if (InfoTool.osName.toLowerCase().contains("win")) {
try {
Runtime.getRuntime().exec("explorer.exe /select," + path);
} catch (IOException ex) {
Main.logger.log(Level.WARNING, ex.getMessage(), ex);
}
}
}
Useful Links:
Links which are similar but no way dublicates or not answered:
How to use java code to open Windows file explorer and highlight the specified file?
Open a folder in explorer using Java
How can I open the default system browser from a java fx application?
More explanation:
Is there a way to do it using JavaFX ?
If not at least i need a link or some way to make the app system
independence.I mean i don't know the default explorer for every OS
that the application is going to work , i need a link or help doing that.
Do i need to write a ton of code to do this?
Is out there any library for doing that?
Do Java9 support that?
Finally:
It is very strange that for so common things i can't find answers and libraries .
Example of highlighted or selected in Windows 10:
Windows
Runtime.getRuntime().exec("explorer /select, <file path>")
Linux
Runtime.getRuntime().exec("xdg-open <file path>");
MacOS
Runtime.getRuntime().exec("open -R <file path>");
Since Java 9 it's possible with the new method browseFileDirectory, so your method would state:
import java.awt.Desktop;
import java.io.File;
...
/**
* Opens the file with the System default file explorer.
*
* #param path the path
*/
public static void openFileLocation(String path) {
Desktop.getDesktop().browseFileDirectory(new File(path));
}
For more information, refer to the javadoc:
https://docs.oracle.com/javase/10/docs/api/java/awt/Desktop.html#browseFileDirectory(java.io.File)
The following is a partial answer showing you how to open the system folder you desire, but not how to highlight a specific file since I do not believe it is possible to highlight a file in a system folder, because that is probably a system OS function that cannot be accessed by Java.
This is written in Javafx code
In your Main class make a variable for Hostservices. Note that "yourFileLocation" is the address of the folder to the file, and SettsBtn is a button that exists somewhere which the user clicks to execute the code:
public class Main extends Application{
static HostServices Host; //<-- sort of a global variable
//some code here to make your GUI
public Main() {
//more code here to initialize things
}
public void start(Stage primaryStage) throws Exception {
//some code here to set the stage
//This code here opens the file explorer
SettsBtn.setOnMouseClicked(e-> {
Path partPath = Paths.get("yourFileLocation");
Host = getHostServices();
Host.showDocument(partPath.toUri().toString());
});
}
}
Note that you could directly open the file by making a string to the file location and the file name with its extension, such as:
Path partPath = Paths.get("yourFileLocation"+"\\"+"yourFileName.ext");
As of Java 17 the Desktop::browseFileDirectory method is still not supported on Windows 10 or later.
The historic reason is that Apple originally implemented these native Desktop integration features for Mac OS X in the com.apple.eawt package back when Apple itself was still maintaining the JDK for Mac OS X. All of that was ported into java.awt.Desktop for Java 9 as per JEP 272: Platform-Specific Desktop Features and so I guess some of these features are still only implemented for Mac OS X to this day.
Fortunately, Windows 10 does have a SHOpenFolderAndSelectItems function that we can call via JNA like so:
public interface Shell32 extends com.sun.jna.platform.win32.Shell32 {
Shell32 INSTANCE = Native.load("shell32", Shell32.class, W32APIOptions.DEFAULT_OPTIONS);
HRESULT SHParseDisplayName(WString pszName, Pointer pbc, PointerByReference ppidl, WinDef.ULONG sfgaoIn, Pointer psfgaoOut);
HRESULT SHOpenFolderAndSelectItems(Pointer pidlFolder, WinDef.UINT cidl, Pointer apidl, WinDef.DWORD dwFlags);
}
public class Shell32Util extends com.sun.jna.platform.win32.Shell32Util {
public static Pointer SHParseDisplayName(File file) {
try {
PointerByReference ppidl = new PointerByReference();
// canonicalize file path for Win32 API
HRESULT hres = Shell32.INSTANCE.SHParseDisplayName(new WString(file.getCanonicalPath()), null, ppidl, new WinDef.ULONG(0), null);
if (W32Errors.FAILED(hres)) {
throw new Win32Exception(hres);
}
return ppidl.getValue();
} catch (Exception e) {
throw new InvalidPathException(file.getPath(), e.getMessage());
}
}
public static void SHOpenFolderAndSelectItems(File file) {
Pointer pidlFolder = SHParseDisplayName(file);
try {
HRESULT hres = Shell32.INSTANCE.SHOpenFolderAndSelectItems(pidlFolder, new WinDef.UINT(0), null, new WinDef.DWORD(0));
if (W32Errors.FAILED(hres)) {
throw new Win32Exception(hres);
}
} catch (Exception e) {
throw new InvalidPathException(file.getPath(), e.getMessage());
}
}
}
So I've tried various reading various fixes for this problem on stack exchange most say to use getResourceAsStream() method, which I have done.
This is my Resource input method for the Jar .
import java.io.InputStream;
public class ResourceLoader {
public static InputStream load(String path){
InputStream input = ResourceLoader.class.getResourceAsStream(path);
if(input == null){
input = ResourceLoader.class.getResourceAsStream("/" + path);
}
return input;
}
}
This is then used in my ImageLoader class.
public class ImageLoader {
public BufferedImage load(String path){
try {
// return ImageIO.read(getClass().getResource(path));
return ImageIO.read(ResourceLoader.load(path));
} catch (IOException e) {
e.printStackTrace();
}
return null;
}
}
and the images are loaded in the main program using
ImageLoader loader = new ImageLoader();
spriteSheet = loader.load("/spritesheet.png");
Now in eclipse the game runs and loads all images perfectly fine.
But what I want to do is export it to Jar, which I have done using some tutorials and
have succeeded in exporting it with the resource folder which contains my images that are used. But when I try and run the .jar file this error pops up in the cmd line.
Exception in thread "Thread-2" java,lang.IllegalArgumentException: input == null
!
at javax.imageio.ImageIO.read<Image.IO.java:1348>
at gfx.ImageLoader.load<ImageLoader.java:15>
at man.Gaim.init(Game.java:100>
at main.Game.run<Game.java:150>
at java.lang.Thread.run<Thread.java:722>
So what I'm gathering is that the image file locations are not being read properly or I inputed them wrong somehow which is returning null and none of the images are loading. When the .Jar is run the Panel appears but nothing is painted to it and that error is given.
This program does work perfectly in eclipse with no errors and all images loading.
EDIT 1:
Robermann your solution for the getClass().getClassLoader().getResourceAsStream(path)) works. The only thing is I need to have the image files in a folder with the jar.
For instance I have
Folder:
---File.Jar
---Images.png
---ImageFolder
-------More imgaes in imagefolder.png
I can load all the images when they are located like that. My actual question was when i export a .Jar the Images are also located inside is it possible to just use the images that are located inside the .jar? Or do I have to pack the imgaes in a folder alongside the jar as above, It works but i was more looking for a runnable .Jar that i could just transer to tohers without having them also need the images outside the .jar.
The question of how to load classpath resources is quite recurring, and a bit confusing for a Java newbie: some answers suggest class.getClassLoader().getResourceAsStream, others class.getResourceAsStream, although they have a slight different semantic:
class.getResourceAsStream does a path translation
class.getClassLoader().getResourceAsStream does not translate the path
For better show the difference, I'm going to propose the following test class, which in 4 different ways try to load the same resource (an image), only 2 working depending on the used path. The Jar content-tree is:
The class:
package image;
import java.io.InputStream;
public class ImageLoader {
public static void main(String[] args ){
String cmd = null;
InputStream is = null;
final String image = "save.png";
if("test1".equals(args[0])){
cmd = "ImageLoader.class.getClassLoader().getResourceAsStream(\""+image+"\")";
is = ImageLoader.class.getClassLoader().getResourceAsStream(image); //YES, FOUND
}else if("test2".equals(args[0])){
cmd = "ImageLoader.class.getResourceAsStream(\""+image+"\")";
is = ImageLoader.class.getResourceAsStream(image); //NOT FOUND
}else if("test3".equals(args[0])){
cmd = "ImageLoader.class.getResourceAsStream(\"/"+image+"\")";
is = ImageLoader.class.getResourceAsStream("/"+image); //YES, FOUND
}else if("test4".equals(args[0])){
cmd = "ImageLoader.class.getClassLoader().getResourceAsStream(\"/"+image+"\")";
is = ImageLoader.class.getClassLoader().getResourceAsStream("/"+image); //NOT FOUND
}else {
cmd = " ? ";
}
System.out.println("With "+cmd+", stream loaded: "+(is != null));
}
}
Run with:
java -cp resLoader.jar image.ImageLoader test4
Hope this class can help in understanding the different behaviour.
I've got a java class, calling a native method and trying to load library:
import java.io.UnsupportedEncodingException;
public class Main {
public static native String getMyString(String s);
/**
* #param args
* #throws UnsupportedEncodingException
*/
public static void main(String[] args) throws UnsupportedEncodingException {
// TODO Auto-generated method stub
// System.out.println("here!");
String s2 = getMyString("string text");
for (Byte b : s2.getBytes("UTF-8")) {
System.out.print(b);
System.out.print(",");
}
}
static {
System.loadLibrary("mylib.so");
}
}
The "mylib.so" is in the directory, where Main.class is located.
When I run java Main I get following exception:
Exception in thread "main" java.lang.UnsatisfiedLinkError: no mylib.so in java.library.path
at java.lang.ClassLoader.loadLibrary(ClassLoader.java:1856)
at java.lang.Runtime.loadLibrary0(Runtime.java:845)
at java.lang.System.loadLibrary(System.java:1084)
at Main.<clinit>(Main.java:24)
What should I change for this to wark?
I've tried setting library full path without success
Do the following:
Use System.loadLibrary("mylib");
Copy mylib.so to libmylib.so
Run java -Djava.library.path=/root/ Main
"How to load native library"
public final class NativeLibsLoaderUtil {
private static final String JAVA_LIBRARY_PATH = "java.library.path";
private static final String SYS_PATHS = "sys_paths";
private NativeLibsLoaderUtil() {
}
private static void addLibsToJavaLibraryPath(final String tmpDirName) {
try {
System.setProperty(JAVA_LIBRARY_PATH, tmpDirName);
/* Optionally add these two lines */
System.setProperty("jna.library.path", tmpDirName);
System.setProperty("jni.library.path", tmpDirName);
final Field fieldSysPath = ClassLoader.class.getDeclaredField(SYS_PATHS);
fieldSysPath.setAccessible(true);
fieldSysPath.set(null, null);
} catch (IllegalAccessException | NoSuchFieldException e) {
LOGGER.error(e.getMessage(), e);
}
}
}
Where tmpDirName is a directory where you store your library.
Or you can modify above class and use temp directory from your system property, like this:
/**
* Temporary directory system property name
*/
private static final String JAVA_IO_TMPDIR = "java.io.tmpdir";
/**
*
* #return
*/
private static File getTempDir() {
final String tmpDirName = System.getProperty(JAVA_IO_TMPDIR);
final File tmpDir = new File(tmpDirName);
if (!tmpDir.exists()) {
tmpDir.mkdir();
}
return tmpDir;
}
!But first you have to copy there your native lib :)
Then to load native library call "addLibsToJavaLibraryPath" method in static block in "most root" class before any class constructor was executed.
static {
NativeLibsLoaderUtil.addLibsToJavaLibraryPath("/tmp");
}
You should add the so to library path:
-Djava.libarary.path= (this is in the java command).
if you run from eclipse:
How to add native library to "java.library.path" with Eclipse launch (instead of overriding it)
If you compiled opencv, on installation you should have seen something like:
make install:
-- Up-to-date: /usr/local/share/java/opencv4/libopencv_java460.so
-- Up-to-date: /usr/local/share/java/opencv4/opencv-460.jar
make a hard link to the /usr/lib/ folder:
$ sudo ln /usr/local/share/java/opencv4/libopencv_java460.so /usr/lib/libopencv_java460.so
And then just run:
System.loadLibrary(Core.NATIVE_LIBRARY_NAME);
that he will get the *.so
As Reimeus answered.
Or you can use
System.load("/Library/Path/libsample.so");
I'm running JRuby as such:
Main jrubyRunner = new Main()
jrubyRunner.main(sassCompileCommandLineArgs)
I have some gems I've compiled into jars. How do I include those jars on the classpath that jrubyRunner will use?
private static def setupCompassInvocationArgs =
['-e', "require 'rubygems';gem 'compass'; load Gem.bin_path('compass', 'compass')"]
protected def runCompassCommand(def compassArgs) {
Main main = new Main()
main.run([setupCompassInvocationArgs, compassArgs].flatten() as String[])
}
The first bit is what you need to load various gems.
Here's the background of the underlying problem, I am collaborating with a group on a project which uses Swt libraries and I am trying to package the software for deployment. As it turns out SWT is very platform/architecture dependent. I would like to be able to package all six jars (linux, mac, win and 32/64-bit) into the same package and use the appropriate library depending on the system. I realize that it is a tough challenge however, switching to Swing (or anything else) isn't really an option right now.
I have found a number of relevant threads (#Aaron Digulla's thread and #mchr's thread) which provided me valuable insights regarding the problem at hand. I have tried to implement the solution proposed by #Alexey Romanov here. With one difference, as the loadSwtJar() method he proposes is not static, I instantiate the object, and immediately following that, run the method before anything else is done to the object.
It appears as the loading procedure doesn't work properly. My reasoning for this statement is as follows:
If all Swt jars are removed from the classpath of the executable jar file, then Exception in thread "main" java.lang.NoClassDefFoundError: org/eclipse/swt/events/MouseListener is thrown which is caused by: java.lang.ClassNotFoundException: org.eclipse.swt.events.MouseListener
to me this means that the libraries are not found on classpath, am I mistaken?
If swt jars are left on the classpath then the first jar file is used by the system during execution. Meaning if gtk-linux-x86_64 happens to be the first swt jar on the list of jars then the system tries to use that, regardless if the system is win32 or Mac OSX.
I have tried to add some output to see if the loadSwtJar() method is choosing the right jar, and the output seems right on all platforms I have tried, as in the right package is selected (and the files do exist in the runnable jar). But nevertheless the right library is not loaded hence execution errors occur:
Exception in thread "main" java.lang.reflect.InvocationTargetException caused by for ex: Caused by: java.lang.UnsatisfiedLinkError: Cannot load 32-bit SWT libraries on 64-bit JVM
(Note that this is the error I get on my Linux machine if I change the order of appearance of 64-bit and 32 bit swt libraries on the build.xml file)
So, what seems to be the problem here? Am I missing out on some detail, or is it simply not possible to check system properties and load an appropriate library accordingly?
Finally below is an excerpt of my build file, figured it might help finding the source of the problem.
Thanks in advance,
EDIT: After a long debug session with a colleague, the problem is resolved (except an annoying bug regarding Thread management on MacOS as I mentioned here). It involved tweaking with the ANT build as well as the way the main class was written. (The main class, as it turns out, was extending & implementing references from the SWT library which meant that the code wouldn't compile at all, wrapped the main class with another class and loaded the SWT jars from there which seemed to be enough to tackle the problem)
Thanks and regards to everyone who contributed, especially #Aaron. Really appreciated!
Here is a copy of the latest version of my Main class. Let me know if that works for you. I tested it on Linux (32/64bit) and Windows (32bit).
package de.pdark.epen.editor;
import java.io.File;
import java.lang.reflect.Constructor;
import java.lang.reflect.Method;
import java.net.URL;
import java.net.URLClassLoader;
import org.apache.commons.lang.SystemUtils;
import org.apache.commons.lang.exception.ExceptionUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import ch.qos.logback.classic.LoggerContext;
import ch.qos.logback.core.util.StatusPrinter;
import de.pdark.epen.exceptions.WikiException;
public class Main
{
public final static String VERSION = "V0.9 (13.05.2010)"; //$NON-NLS-1$
private final static Logger log = LoggerFactory.getLogger (Main.class);
private static final String ORG_ECLIPSE_SWT_WIDGETS_SHELL = "org.eclipse.swt.widgets.Shell"; //$NON-NLS-1$
/**
* #param args
*/
#SuppressWarnings({"nls", "PMD.SystemPrintln"})
public static void main (String[] args)
{
String msg = "Starting ePen "+VERSION;
System.out.println (msg);
log.info (msg);
LoggerContext lc = (LoggerContext)LoggerFactory.getILoggerFactory ();
StatusPrinter.print (lc);
int rc = 1;
try
{
Main main = new Main ();
main.run (args);
rc = 0;
}
catch (Throwable t) //NOPMD
{
ExceptionUtils.printRootCauseStackTrace (t);
}
finally
{
System.out.println ("Done.");
log.info ("Exit {}", rc);
System.exit (rc); //NOPMD
}
}
#SuppressWarnings({"nls", "PMD.SystemPrintln", "PMD.SignatureDeclareThrowsException"})
private void run (String[] args) throws Exception
{
if (!SystemUtils.isJavaVersionAtLeast (150))
{
System.out.println ("Version="+SystemUtils.JAVA_VERSION_INT);
throw new WikiException ("Need at least Java 5 but this Java is only "+SystemUtils.JAVA_VERSION);
}
loadSwtJar ();
URLClassLoader cl = (URLClassLoader) getClass().getClassLoader(); //NOPMD
Class<?> c = cl.loadClass ("de.pdark.epen.editor.EPenEditor");
Class<?> shellClass = cl.loadClass (ORG_ECLIPSE_SWT_WIDGETS_SHELL);
Constructor<?> ctor = c.getConstructor (shellClass);
Object obj = ctor.newInstance (new Object[] { null });
Method run = c.getMethod ("run", args.getClass ()); //$NON-NLS-1$
run.invoke (obj, new Object[] { args });
}
#SuppressWarnings({"nls", "PMD"})
private void loadSwtJar ()
{
try {
Class.forName (ORG_ECLIPSE_SWT_WIDGETS_SHELL);
// Already on classpath
return;
} catch (ClassNotFoundException e) {
// Add the JAR
}
String osName = SystemUtils.OS_NAME.toLowerCase ();
String osArch = SystemUtils.OS_ARCH.toLowerCase ();
String swtFileNameOsPart =
osName.contains("win") ? "win32" :
osName.contains("mac") ? "macosx" :
osName.contains("linux") || osName.contains("nix") ? "linux" :
null;
String swtFileNameUiPart =
osName.contains("win") ? "win32" :
osName.contains("mac") ? "cocoa" :
osName.contains("linux") || osName.contains("nix") ? "gtk" :
null;
if (null == swtFileNameOsPart)
{
throw new RuntimeException ("Can't determine name of SWT Jar from os.name=[" + osName + "] and os.arch=["
+ osArch + "]");
}
String swtFileNameArchPart = osArch.contains ("64") ? ".x86_64" : ".x86";
if(".x86".equals(swtFileNameArchPart) && "macosx".equals(swtFileNameOsPart)) {
swtFileNameArchPart = "";
}
String swtFileName = "org.eclipse.swt." + swtFileNameUiPart + "." + swtFileNameOsPart + swtFileNameArchPart + "-3.6.0.jar";
File file = new File ("swt", swtFileName);
if (!file.exists ())
{
throw new RuntimeException ("Can't locate SWT Jar " + file.getAbsolutePath ());
}
try
{
URLClassLoader classLoader = (URLClassLoader) getClass ().getClassLoader ();
Method addUrlMethod = URLClassLoader.class.getDeclaredMethod ("addURL", URL.class);
addUrlMethod.setAccessible (true);
URL swtFileUrl = file.toURI ().toURL ();
log.info ("Adding {} to the classpath", swtFileUrl);
addUrlMethod.invoke (classLoader, swtFileUrl);
}
catch (Exception e)
{
throw new RuntimeException ("Unable to add the swt jar to the class path: " + file.getAbsoluteFile (), e);
}
}
}
You could use Java Web Start as a bootstrap mechanism for your multi platform SWT application. See a corresponding entry in SWT FAQ.
Alternatively, you could put SWT native libraries for each platform into a separate folders and specify them -Djava.library.path in your platform-specific startup script.