title: Is it possible to select a classpath jar on application startup?
body: <p>ie:</p>
  
  <pre><code>main_or_init()
  {
      if(some platform specific condition) {
          addToClassPath("jarFileA.jar");
      } else {
          addToClassPath("JarFileB.jar");
      }
  
      // which implementation selected above 
      ClassFromJarFile firstInstance = new ClassFromJarFile();
  }
  </code></pre>
  
  <p>Note: yes other ways of loading, factories etc.  But if this can be done, then an entire platform specific package implementation might be dynamically selected at application startup.</p>