How to Add .So File to the Java.Library.Path in Linux

How to add .so file to the java.library.path in Linux

Add the containing directory to LD_LIBRARY_PATH before launching the application

        export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/some/pathOfContainingDirectory

Use java -XshowSettings:properties to show the java.library.path (and others) value.

How to include a directory to java.library.path on Linux/Debian?

You can do this via adding the containing directory to LD_LIBRARY_PATH like

export LD_LIBRARY_PATH = $LD_LIBRARY_PATH:/Desktop/pathOfContaininglibaryDirectory

into your bashrc file.Then you need to refresh bashrc file via command

source ~/.bashrc

then run you can run the java command(java -XshowSettings:properties) to see all the properties it will come under user.dir

How could set the java.library.path in Linux from I am trying JNI

This seems like path issue, where your is not found in "sybase/IQ-16_0/jim_samples/udf/hellojni" directory.

Remember 'lib' prefix is important in your file (if you are running this in Linux), just will not work.

Loading a Linux .so File at Java Runtime

Libraries on Linux are often named in the pattern, and I believe Java follows that convention. So System.loadLibrary("Sample") may be looking for You can verify this by making a quick test program to call System.mapLibraryName and checking the output.

To resolve the issue, assuming this is in fact the problem you're having, you can either rename your library file or use System.load (not System.loadLibrary), which will load the library specified by the exact filename you pass it, without any transformations. The latter method is not portable across platforms, though.

Why java.library.path is not working on ubuntu?

So my question is why java.library.path is not works for ubuntu (linux)? Is it like java.library.path is only for windows?

It does work, we use it a lot. Start your application with -XshowSettings:properties and take a look at the search path for debugging.

We usually deploy the libraries as a package to /usr/local/lib, since the libraries are often used by other components too. Don't forget to call ldconfig after placing a new library in there (so much for the export LD_LIBRARY_PATH part).

As far as i remember it should be enough with just adding the folder with -Djava.library.path if i recall correctly. I will look into it and tell you later to clarify.

Also please post readlink -f /home/ubuntu/Desktop/bin, file /home/ubuntu/Desktop/bin/ and ldd /home/ubuntu/Desktop/bin/

I will try to explain why things work and why not.

Lets talk about java.library.path. This property is used by the VM for looking up libraries. Take a look at java.lang.System#load*(String libName) for reference. The java.library.path property has some paths pre-set, the following shows the output on my ubuntu box:

ortang@vbox-devel:~$ java -XshowSettings:properties
Property settings:
java.library.path = /usr/java/packages/lib/amd64

Be aware that using this property will overwrite the existing property.

ortwin@vbox-devel:~$ java -Djava.library.path=/some/other/folder:/yet/another/one -XshowSettings:properties
Property settings:
java.library.path = /some/other/folder

So far so good. The JVM is looking only in the folders defined in that property!

The libraries you make the JVM to load will most likely have dependencies to other libraries. Be aware that these dependencies are looked up by the operating system, just as any other shared library!

So to solve your problem you have to make sure that the libraries you load have their dependencies resolved! Use ldd for debugging that matter.

The LD_LIBRARY_PATH environment variable does a similar job, as it adds paths that will be used for library lookup by the OS. I am no fan of using it in production environments.

Load .so file from a jar

First, we need to make sure the JAR file is in the class path. Then, here is a simple way of loading the library, assuming it is found under /com/example/ in the JAR:

    InputStream is = ClassLoader.class.getResourceAsStream("/com/example/");
File file = File.createTempFile("lib", ".so");
OutputStream os = new FileOutputStream(file);
byte[] buffer = new byte[1024];
int length;
while ((length = != -1) {
os.write(buffer, 0, length);


But this glosses over a lot of corner cases and portability issues that are covered by JavaCPP inside the Loader class.

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