ConcurrentTransformer

gistfile1.java

protected class ConcurrentTransformer {

     private final Lock lock = new ReentrantLock();
     private URL url = null;
     private volatile Templates template = null;
     private long lastCompileTime = Long.MAX_VALUE;

     protected Templates generateTemplate(long ladezeitProzessApp) throws TransformerFactoryConfigurationError, TransformerConfigurationException, InterruptedException {
         if (!mustCompile(loadTimeApplication)) {
             return template;
         }
         lock.lockInterruptibly(); 
         try {           
             if (!mustCompile(loadTimeApplication)) {
                 return template;
             }
             bouncer.acquire(); 
             try {
                 TransformerFactory transFactory = TransformerFactory.newInstance();
                 URIResolver resolver = transFactory.getURIResolver();
                 transFactory.setURIResolver(new XMLTransformResolver(resolver));
                 StreamSource source = new StreamSource(url.toExternalForm());
                 template = transFactory.newTemplates(source);
                 lastCompileTime = System.currentTimeMillis();
                 return template;
             } finally {
                 bouncer.release();
             }
         } finally {
             lock.unlock();
         }
     }

     private boolean mustCompile(long loadTimeApplication) {
         return template == null || !templateCacheActive || requiresRecompile(loadTimeApplication);
     }

}