Avoid NoSuchElementException

[dpolivaev]

If bundle class loader should find a resource from package loaded by application class loader and this resource is not available, it currently throws NoSuchElementException instead of returning null.

Exception in thread "main" 
java.util.NoSuchElementException
    at sun.misc.CompoundEnumeration.nextElement(CompoundEnumeration.java:59)
    at org.knopflerfish.framework.BundleClassLoader.findResource(BundleClassLoader.java:213)
    at org.knopflerfish.framework.BundleClassLoader.getResource(BundleClassLoader.java:391)
    at org.freeplane.launcher.Launcher.launchWithoutUICheck(Launcher.java:279)

It happens because it delegates to application class loader

<init>:39, CompoundEnumeration (sun.misc)
getResources:1144, ClassLoader (java.lang)
frameworkSearchFor:887, BundleClassLoader (org.knopflerfish.framework)
searchFor0:715, BundleClassLoader (org.knopflerfish.framework)
searchFor:613, BundleClassLoader (org.knopflerfish.framework)
run:561, SecurePermissionOps$3 (org.knopflerfish.framework)
doPrivileged:-1, AccessController (java.security)
callSearchFor:558, SecurePermissionOps (org.knopflerfish.framework)
getBundleResources:513, BundleClassLoader (org.knopflerfish.framework)
findResource:211, BundleClassLoader (org.knopflerfish.framework)
getResource:391, BundleClassLoader (org.knopflerfish.framework)
launchWithoutUICheck:279, Launcher (org.freeplane.launcher)
main:75, Launcher (org.freeplane.launcher)

which can return non null enumeration which is empty.

The pull request adds a check for this case.

[dpolivaev]

(the version of freeplane launcher containing this call to getResource is not submitted to git, it was only created for test. The exception is thrown from line URL resource = classLoader.getResource(foo);)

    private Controller launchWithoutUICheck(String[] args) {
        if(freeplaneLaunched)
            throw new IllegalStateException("Freeplane already launched");
        freeplaneLaunched = true;
        setDefines();
        if (! disableSecurityManager)
            System.setSecurityManager(new SecurityManager(){

                @Override
                public void checkConnect(String pHost, int pPort, Object pContext) {
                    if(pContext != null)
                        super.checkConnect(pHost, pPort, pContext);
                    else
                        super.checkConnect(pHost, pPort);
                }

            });
        setArgProperties(args);
        final Controller controller = startFramework();
        ClassLoader classLoader = controller.getClass().getClassLoader();
        String foo = Controller.class.getPackage().getName().replace('.', '/') + '/' + "foo.txt";
        URL resource = classLoader.getResource(foo);
        return controller;
    }

[chlarsson]

Thanks for the PR. We'll have a closer look at it in a day or two.

Thanks, Christer

[janste63]

Thanks for the fix.