Class URLClassLoader

public class URLClassLoaderextends SecureClassLoaderimplements Closeable

###URLClassLoader可以远程加载资源类。

This class loader is used to load classes and resources from a search path of URLs referring to both JAR files and directories. 

Any URL that ends with a '/' is assumed to refer to a directory. Otherwise, the URL is assumed to refer to a JAR file which will be opened as needed.

The AccessControlContext of the thread that created the instance of URLClassLoader will be used when subsequently loading classes and resources.

The classes that are loaded are by default granted permission only to access the URLs specified when the URLClassLoader was created.