JMeter源码

private static final String CLASSPATH_SEPARATOR = File.pathSeparator;

private static final DynamicClassLoader loader;

java net url

public static void updateLoader(URL [] urls) {
        DynamicClassLoader loader
            = (DynamicClassLoader) Thread.currentThread().getContextClassLoader();
        for(URL url : urls) {
            loader.addURL(url);
        }
    }

URL／CLASSLOADER