How NOT to reload .class files from the disk in CustomClassLoader for every creation of an instance

I have created a CustomClassLoader that inherits from the ClassLoader to override loadClass method.

Below is the new CustomClassLoaded

    public class DesignFactoryClassLoader extends ClassLoader{

        public DesignFactoryClassLoader(ClassLoader parent) {
            super(parent);
        }

        public String classCanonicalName= null;

        public Class loadClass(String canonicalName) throws ClassNotFoundException {
             if(!this.classCanonicalName.equals(canonicalName))
                    return super.loadClass(canonicalName);
            try {                   

                    String currentDirectory =  new java.io.File( "." ).getCanonicalPath().replace("bin", "");
                    String pathToClassFiles = currentDirectory + "/webapps/wb5/WEB-INF/classes";
                    String pathToClassFile =  pathToClassFiles + "/" + canonicalName.replace(".", "/") + ".class";


                    File file = new File(pathToClassFile);                
                    @SuppressWarnings("deprecation")
                    URL myUrl = file.toURL();
                    URLConnection connection = myUrl.openConnection();
                    InputStream input = connection.getInputStream();
                    ByteArrayOutputStream buffer = new ByteArrayOutputStream();
                    int data = input.read();

                    while(data != -1){
                        buffer.write(data);
                        data = input.read();
                    }
                    input.close();
                    byte[] classData = buffer.toByteArray();

                    return defineClass(canonicalName,
                            classData, 0, classData.length);
                } catch (Exception e) {
                    //TODO Auto-generated catch block
                    e.printStackTrace();
                }
            return null;
          }
}

To reload a particular class from the disk this is how I do it

ClassLoader parentClassLoader = DesignFactory.class.getClassLoader();
DesignFactoryClassLoader designFactoryClassLoader = new DesignFactoryClassLoader(parentClassLoader);
designFactoryClassLoader.classCanonicalName = classCanonicalName;
Class reloadedCls = designFactoryClassLoader.loadClass(classCanonicalName);

The problem that I now have is: When I needed to create an instance of MyClass after the MyClass.class has been modified I created it using the CustomClassLoader. The next time I need to created an instance I dont have to reload the .class from the disk again. How can I avoid this?