Hello This is my code :
if (isWindows()) {
//System.setProperty("jna.library.path", getClass().getResource("/resources/win32-x86").getPath());//netbeans WinOs
System.setProperty("jna.library.path", System.getProperty("user.dir").toString()+File.separator+"Desktop");//compiler WinOs
} else if (isMac()) {
//System.setProperty("jna.library.path", getClass().getResource("/resources").getPath());//netbeans MacOs
System.setProperty("jna.library.path", System.getProperty("user.dir").toString()+File.separator+"Desktop");//compiler MacOs
} else {
System.out.println("Your OS is not support!!");
}
Why I have 2 PATH (don't understand because for add an image i have only one Path) by OS, one for use with IDE and another for use with .JAR ?
I just realized, that when I'm use windows and I run the project (from netbeans) the "Library" load and I get the information, but when I compile and I launch my .jar I get error :
Exception in thread "AWT-EventQueue-0" java.lang.UnsatisfiedLinkError: %1 is not a valid Win32 application.
My Structure
It is correct?
On mac only work with this command : java -jar "/System/Volumes/Data/Users/hugoclo/NetBeansProjects/Prezauto/dist/Prezauto.jar"since Terminal. If click on jar i have message error : Not Found .....
Sorry about my English,
There can be two reasons for the "why". While Java is cross-platform, JNA (which relies on some native code) must necessarily behave differently on different operating systems. Particularly in the case of loading DLLs (Windows) or dynamic libraries (OSX), you don't want to mix and match. Because it might be possible to have a dll with the same name compiled for different operating systems, JNA's Getting Started page identifies standard locations for these libraries:
Make your target library available to your Java program. There are several ways to do this:
The preferred method is to set the jna.library.path system property to the path to your target library. This property is similar to java.library.path, but only applies to libraries loaded by JNA.
Change the appropriate library access environment variable before launching the VM. This is PATH on Windows, LD_LIBRARY_PATH on Linux, and DYLD_LIBRARY_PATH on OSX.
Make your native library available on your classpath, under the path {OS}-{ARCH}/{LIBRARY}, where {OS}-{ARCH} is JNA's canonical prefix for native libraries (e.g. win32-x86, linux-amd64, or darwin). If the resource is within a jar file it will be automatically extracted when loaded.
In your code, you appear to be trying to do the first option (setting the jna.library.path) to include the user's desktop. That's fine for testing, not good for production, and likely the reason your compiled jar can't find it. Furthermore, by setting this variable, you are overwriting any previous (default) location for it. If you want to go this route, you should copy the saved location and then append your own additional path to it.
However, for code you'll distribute to users, you don't want to have to rely on an absolute file path. It's far better to put the library in a standard relative path location: a resources path (src/main/resources if using Maven) that will be available on your (or any user's) classpath when executing. This seems to align with the commented-out Windows branch of your code, which will look in the win32-x86 subdirectory of your resources folder.
You may have told your IDE to add something to the classpath (so it works there) but if it's not in a standard location, it may fail in a jar.
I'm not sure why the macOS branch of your code does not put the resources in the darwin subdirectory but it probably should.
I currently wrote a simple GUI in Eclipse which runs as intended. I was hoping to export it so I can share it with my friend (who doesn't need to install eclipse and the java libraries). I tried all 3 library handling method Eclipse provides and none of them works. I read a little online and saw something about a manifest file, but wasn't quite sure what to do with it. Is it going to help?
This is where I placed the folder that comes with the .dll file.
This is the result. Am I doing something wrong?
As indicated by the error messages in the first screenshot, what you are missing here is the native library - the software library written and compiled to native code specific to the operating system. What you will need to do is provide the libraries specific to the operating system on which your software will run, eg. dlls for 32 or 64 bit Windows. The manifest does not provide the capability to include those libraries.
When the program is run on Windows, Java will look for native libraries in the following locations:
The current directory
The directories in the PATH environment variable
The directories in java.library.path (if it's specified)
It may be easiest to simply put all files in the one directory. If you do this, you should be able to run the program in the same way as you do now.
The java.library.path option is only needed if you want to put your native library files in a directory separate to the one in which you run your program and not on your PATH. It is only in this case that you will need to add java.library.path, eg. by adding -Djava.library.path=c:\path\to\your\lib after java. Also note that you may use a relative path, ie. a path that is relative to the directory you are in when you execute the command.
I also see from your later error messages that you have another dependency, but on a java library LeapJava.jar. As running a jar with -jar will only work if you have a single jar, but because you have more than one (your own program plus the dependency), you'll instead need to use the -classpath (or -cp for short) argument and add your main class. The classpath argument is a semicolon-separated list of classpath locations, while the main class is the one containing your public static void main method, eg. your.package.name.YourMainClass. So assuming your UI.jar is still in C:\Users\Ian\Desktop\Leap Data UI, you should be able to navigate to that directory and execute with:
java -cp UI.jar;UI_lib\LeapJava.jar -Djava.library.path="UI_lib\x64" your.package.name.YourMainClass
How can I load a custom dll file in my web application? I've tried the following:
Copied all required dlls in system32 folder and tried to load one of them in Servlet constructor System.loadLibrary
Copied required dlls into tomcat_home/shared/lib and tomcat_home/common/lib
All these dlls are in WEB-INF/lib of the web-application
In order for System.loadLibrary() to work, the library (on Windows, a DLL) must be in a directory somewhere on your PATH or on a path listed in the java.library.path system property (so you can launch Java like java -Djava.library.path=/path/to/dir).
Additionally, for loadLibrary(), you specify the base name of the library, without the .dll at the end. So, for /path/to/something.dll, you would just use System.loadLibrary("something").
You also need to look at the exact UnsatisfiedLinkError that you are getting. If it says something like:
Exception in thread "main" java.lang.UnsatisfiedLinkError: no foo in java.library.path
then it can't find the foo library (foo.dll) in your PATH or java.library.path. If it says something like:
Exception in thread "main" java.lang.UnsatisfiedLinkError: com.example.program.ClassName.foo()V
then something is wrong with the library itself in the sense that Java is not able to map a native Java function in your application to its actual native counterpart.
To start with, I would put some logging around your System.loadLibrary() call to see if that executes properly. If it throws an exception or is not in a code path that is actually executed, then you will always get the latter type of UnsatisfiedLinkError explained above.
As a sidenote, most people put their loadLibrary() calls into a static initializer block in the class with the native methods, to ensure that it is always executed exactly once:
class Foo {
static {
System.loadLibrary('foo');
}
public Foo() {
}
}
Changing 'java.library.path' variable at runtime is not enough because it is read only once by JVM. You have to reset it like:
System.setProperty("java.library.path", path);
//set sys_paths to null
final Field sysPathsField = ClassLoader.class.getDeclaredField("sys_paths");
sysPathsField.setAccessible(true);
sysPathsField.set(null, null);
Please, take a loot at: Changing Java Library Path at Runtime.
The original answer by Adam Batkin will lead you to a solution, but if you redeploy your webapp (without restarting your web container), you should run into the following error:
java.lang.UnsatisfiedLinkError: Native Library "foo" already loaded in another classloader
at java.lang.ClassLoader.loadLibrary0(ClassLoader.java:1715)
at java.lang.ClassLoader.loadLibrary(ClassLoader.java:1646)
at java.lang.Runtime.load0(Runtime.java:787)
at java.lang.System.load(System.java:1022)
This happens because the ClassLoader that originally loaded your DLL still references this DLL. However, your webapp is now running with a new ClassLoader, and because the same JVM is running and a JVM won't allow 2 references to the same DLL, you can't reload it. Thus, your webapp can't access the existing DLL and can't load a new one. So.... you're stuck.
Tomcat's ClassLoader documentation outlines why your reloaded webapp runs in a new isolated ClassLoader and how you can work around this limitation (at a very high level).
The solution is to extend Adam Batkin's solution a little:
package awesome;
public class Foo {
static {
System.loadLibrary('foo');
}
// required to work with JDK 6 and JDK 7
public static void main(String[] args) {
}
}
Then placing a jar containing JUST this compiled class into the TOMCAT_HOME/lib folder.
Now, within your webapp, you just have to force Tomcat to reference this class, which can be done as simply as this:
Class.forName("awesome.Foo");
Now your DLL should be loaded in the common classloader, and can be referenced from your webapp even after being redeployed.
Make sense?
A working reference copy can be found on google code, static-dll-bootstrapper .
You can use System.load() to provide an absolute path which is what you want, rather than a file in the standard library folder for the respective OS.
If you want native applications that already exist, use System.loadLibrary(String filename). If you want to provide your own you're probably better with load().
You should also be able to use loadLibrary with the java.library.path set correctly. See ClassLoader.java for implementation source showing both paths being checked (OpenJDK)
In the case where the problem is that System.loadLibrary cannot find the DLL in question, one common misconception (reinforced by Java's error message) is that the system property java.library.path is the answer. If you set the system property java.library.path to the directory where your DLL is located, then System.loadLibrary will indeed find your DLL. However, if your DLL in turn depends on other DLLs, as is often the case, then java.library.path cannot help, because the loading of the dependent DLLs is managed entirely by the operating system, which knows nothing of java.library.path. Thus, it is almost always better to bypass java.library.path and simply add your DLL's directory to LD_LIBRARY_PATH (Linux), DYLD_LIBRARY_PATH (MacOS), or Path (Windows) prior to starting the JVM.
(Note: I am using the term "DLL" in the generic sense of DLL or shared library.)
If you need to load a file that's relative to some directory where you already are (like in the current directory), here's an easy solution:
File f;
if (System.getProperty("sun.arch.data.model").equals("32")) {
// 32-bit JVM
f = new File("mylibfile32.so");
} else {
// 64-bit JVM
f = new File("mylibfile64.so");
}
System.load(f.getAbsolutePath());
For those who are looking for java.lang.UnsatisfiedLinkError: no pdf_java in java.library.path
I was facing same exception; I tried everything and important things to make it work are:
Correct version of pdf lib.jar ( In my case it was wrong version jar kept in server runtime )
Make a folder and keep the pdflib jar in it and add the folder in your PATH variable
It worked with tomcat 6.
If you believe that you added a path of native lib to %PATH%, try testing with:
System.out.println(System.getProperty("java.library.path"))
It should show you actually if your dll is on %PATH%
Restart the IDE Idea, which appeared to work for me after I setup the env variable by adding it to the %PATH%
The issue for me was naming:
The library name should begin with "lib..." such as libnative.dll.
So you might think you need to load "libnative": System.loadLibrary("libnative")
But you actually need to load "native": System.loadLibrary("native")
Poor me ! spent a whole day behind this.Writing it down here if any body replicates this issue.
I was trying to load as Adam suggested but then got caught with AMD64 vs IA 32 exception.If in any case after working as per Adam's(no doubt the best pick) walkthrough,try to have a 64 bit version of latest jre.Make sure your JRE AND JDK are 64 bit and you have correctly added it to your classpath.
My working example goes here:unstatisfied link error
I'm using Mac OS X Yosemite and Netbeans 8.02, I got the same error and the simple solution I have found is like above, this is useful when you need to include native library in the project. So do the next for Netbeans:
1.- Right click on the Project
2.- Properties
3.- Click on RUN
4.- VM Options: java -Djava.library.path="your_path"
5.- for example in my case: java -Djava.library.path=</Users/Lexynux/NetBeansProjects/NAO/libs>
6.- Ok
I hope it could be useful for someone.
The link where I found the solution is here:
java.library.path – What is it and how to use
It is simple just write java -XshowSettings:properties on your command line in windows and then paste all the files in the path shown by the java.library.path.
I had the same problem and the error was due to a rename of the dll.
It could happen that the library name is also written somewhere inside the dll.
When I put back its original name I was able to load using System.loadLibrary
First, you'll want to ensure the directory to your native library is on the java.library.path. See how to do that here. Then, you can call System.loadLibrary(nativeLibraryNameWithoutExtension) - making sure to not include the file extension in the name of your library.
I'm a little confused by this error. I'm new to Java and the error seems pretty self explanatory, but I've checked my paths (even defined my own) and it still fails to find this library. Is there something I'm doing wrong? See directory screenshot and error screenshot below:
UPDATE
UPDATE 2
If I create a new NetBeans project this works fine. Same code and everything. If I create new IntelliJ project I get this error above. I must be missing something in IntelliJ
UPDATE 3
Found the solution. Adding dependencies is a bit different in IntelliJ. Thanks all for the help.
http://www.jetbrains.com/idea/webhelp/configuring-module-dependencies-and-libraries.html
Obidisc4j is a .jar file. You just dont see its extension in the explorer.
Regular jar files are not loaded by System.loadLibrary. They are automatically loaded by the JVM's classLoader.
You are using a native library. It doen't matter if that library is in the classpath. There are 4 ways you can make the Java runtime load your shared library at runtime:
Call System.load to load the .so from an explicitly specified absolute path.
Copy the shared library to one of the paths already listed in java.library.path
Modify the LD_LIBRARY_PATH environment variable to include the directory where the shared library is located.
Specify the java.library.path on the command line by using the -D option.
Seems like your application is trying to find out a obidisc4j.dll (for Windows) or obidisc4j.so (for Linux). The file must be present on the PATH (but not the classpath). If you are not sure what PATH is your Java application searching in, you can write the following statement, before the point where the exception takes place, to find out the PATH.
System.out.println(System.getProperty("java.library.path"));
This will tell you about the paths where your DLL or SO file should be placed. You just need to place the file in ONE of those N-paths.
I'm having a difficult time figuring this one out. I have an eclipse project where I created a user library which includes the jar file opencv_java245.jar.
I've tried everything I can think of, adding the jar to the path, adding the directory of the jar to the path variable.
I checked my java versions, I've tried VM arguments in run config.
I still get the same UnsatisfiedLinkError on this line System.loadLibrary("opencv_java245");
Right now I have a user library with opencv-245.jar located in C:\OpenCV\opencv\build\java
The Native Library Location for it is located in C:/OpenCV/opencv/build/java
My PATH variable also has that same location added to it.
System.loadLibrary(Core.NATIVE_LIBRARY_NAME);
this the code for detect default dll file..
Actually for future reference for anyone I found the solution. Inside the java folder for OpenCV there is a x64 and x86 folder containing dll files for OpenCV. Copy over either 64 bit or 32 bit dll file to your java folder for OpenCV and it should work.