Working with libpath with java reflection.
- by C. Ross
I'm dynamically loading a class and calling a method on it. This class does JNI. When I call the class, java attempts to load the library. This causes an error because the library is not on the libpath. I'm calling from instead a jar so I can't easily change the libpath (especially since the library is not in the same directory or a sub directory of the jar). I do know the path of the library, but how can I load it before I load the class.
Current code:
public Class<?> loadClass(String name) throws ClassNotFoundException {
if(!CLASS_NAME.equals(name))
return super.loadClass(name);
try {
URL myUrl = new URL(classFileUrl);
URLConnection connection = myUrl.openConnection();
InputStream input = connection.getInputStream();
byte[] classData = readConnectionToArray(input);
return defineClass(CLASS_NAME,
classData, 0, classData.length);
} catch (MalformedURLException e) {
throw new UndeclaredThrowableException(e);
} catch (IOException e) {
throw new UndeclaredThrowableException(e);
}
}
Exception:
Can't find library libvcommon.so
java.lang.UnsatisfiedLinkError: vcommon (A file or directory in the path name does not exist.)
at java.lang.ClassLoader.loadLibraryWithPath(ClassLoader.java:998)
at java.lang.ClassLoader.loadLibraryWithClassLoader(ClassLoader.java:962)
at java.lang.System.loadLibrary(System.java:465)
at vcommon.(vcommon.java:103)
at java.lang.J9VMInternals.initializeImpl(Native Method)
at java.lang.J9VMInternals.initialize(J9VMInternals.java:200)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:37)
at java.lang.reflect.Method.invoke(Method.java:599)
at com.fortune500.fin.v.vunit.reflection.ReflectionvProcessor.calculateV(ReflectionvProcessor.java:36)
at com.fortune500.fin.v.vunit.UTLTestCase.execute(UTLTestCase.java:42)
at com.fortune500.fin.v.vunit.TestSuite.execute(TestSuite.java:15)
at com.fortune500.fin.v.vunit.batch.Testvendor.execute(Testvendor.java:101)
at com.fortune500.fin.v.vunit.batch.Testvendor.main(Testvendor.java:58)
Related: Dynamic loading a class in java with a different package name
