How to use JNI, but only when available for current platform?

Posted by Mecki on Stack Overflow See other posts from Stack Overflow or by Mecki
Published on 2010-03-12T10:23:09Z Indexed on 2010/03/12 10:27 UTC
Read the original article Hit count: 200

Filed under:

java

|

jni

What is the common way (or best practice) to optionally use JNI?

E.g. I have a Java class and this class is 100% pure Java, so it can run on all platforms. However, on some platforms I'd like to speed up some heavy calculations using JNI - which works fine. Unfortunately I cannot support any existing Java platform in the world. So I guess it is fine to initially only support the big three: Linux, Windows, Mac OS X.

So what I'd like to do is to use JNI on those three platforms and use the 100% pure Java version on all other platforms. Now I can think of various ways how to do that (loading class dynamically for example and either loading the JNI class or the pure Java one), but thinking that this is a common issue that thousands of projects had to solve in the past for sure, I'm really surprised to not find any documentation or references to the question how to solve this most elegantly or effectively.

© Stack Overflow or respective owner

Related posts about java

Tomcat 6: Access Control Exception?

as seen on Server Fault - Search for 'Server Fault'
I'm trying to setup a tomcat6 server, and I'm trying to match another setup someone else established. However, my deployment (default Ubuntu install) uses a policy.d/ directory structure, and the established server just uses a catalina.policy file. I've tried setting every entry in policy.d to match… >>> More
Problem in creation MDB Queue connection at Jboss StartUp

as seen on Stack Overflow - Search for 'Stack Overflow'
I am not able to create a Queue connection in JBOSS4.2.3GA Version & Java1.5, as I am using MDB as per the below details. I am putting this MDB in a jar file(named utsJar.jar) and copied it in deploy folder of JBOSS, In the test env. this MDB works well but in another env. [ env settings and… >>> More
failing to establish connection between Postgres db and gwt

as seen on Stack Overflow - Search for 'Stack Overflow'
Hi, I am using Postgres and gwt 2.0 for one of my applications. I am facing problem connecting to the database. When I try to connect it gives "ClassNotFoundException". Here is what I get when I try to connect to database: java.lang.ClassNotFoundException: org.postgresql.Driver at java.net… >>> More
failing to establish connection between postgre db and gwt

as seen on Stack Overflow - Search for 'Stack Overflow'
Hi, For i am using postgre and gwt 2.0 for one of my applications. I am facing problem connecting to the database. When i try to connect it gives "ClassNotFoundException". Here is what i get when i try to connect to database: java.lang.ClassNotFoundException: org.postgresql.Driver at java.net… >>> More
Migration and deployement problems JBoss 4.2.2.GA to JBoss 6.0.0.M2

as seen on Stack Overflow - Search for 'Stack Overflow'
Hi, I'm trying to migrate an application running on JBoss 4.2.2.GA to JBoss 6.0.0.M2 I give you some log to explain my problem : boot.log : 2010-03-16 09:59:29,406 ERROR [org.jboss.system.server.profileservice.ProfileServiceBootstrap] (Thread-2) Failed to load profile: Summary of incomplete deployments… >>> More

Related posts about jni

Implement JNI listener.

as seen on Stack Overflow - Search for 'Stack Overflow'
I have the following code in a c++ "listener class" (more or less), which calls some function of a Java object. I suspect there's a memory leak: JNIEnv *env = NULL; vm_->AttachCurrentThread(&env, NULL); const jclass cls = env->FindClass(...); const jmethodID meth = env->GetMethodID(… >>> More
JNI, cast between jobect and jthrowable

as seen on Stack Overflow - Search for 'Stack Overflow'
Dear colleagues, I need raise an exception from C++ code. Raised exception must contain text and code of error. So common form: ThrowNew(jclass clazz, const char *msg) is not applicable. That is why I want create my own instance of java class: public class MyException extends Exception that… >>> More
Forcing the GC to collect JNI proxy objects

as seen on Stack Overflow - Search for 'Stack Overflow'
Hi. While I do my best to clean JNI objects to free native memory in the end of the usage, there are still some that hang around for a long time, wasting system native memory. Is there any way to force the GC to give priority in collection of these JNI proxies? I mean is there a way to cause GC… >>> More
JNI loses reference to native methods

as seen on Stack Overflow - Search for 'Stack Overflow'
As an example for later use in Android I wrote a simple callback interface. While doing so i ran into the following error or bug or whatever. In C the two commented lines are supposed to be executed resulting in calling the C callback onChange. But instead i get an UnsatisfiedLinkError. Calling the… >>> More
Using Fantom USB Driver from JNI

as seen on Stack Overflow - Search for 'Stack Overflow'
I'm having some difficulty with JNI. I'm using JNI to call some Java methods from a C++ program. This implementation of JNI is working fine. The goal of the Java program is to send commands over USB to a LEGO robot using LEJOS. This works fine when running the Java program by itself but for some… >>> More