Java How to load classes and jar packages through the class loader

Scene:

Put the class files and jars in the project into the D:\loader\terry\codex directory, how to get the project to load and use these classes in code way.

Scenario: Using URLClassLoader constructs D:\loader\terry\codex the class loader under this path, and uses these classes to instantiate through the Java reflection mechanism

Example:

Helloworld.java:

Package terry.codex;

/**
 * @ Writer: Yh.zeng
 * @ Write Time: 2017-12-3 pm 2:29:57
 * @ file Description: Todo/
 public
class HelloWorld {
	
	public void SayHello () {
		System.out.println ("HelloWorld. ");
	}

}

Test.java:

Import Java.io.File;
Import Java.lang.reflect.Method;
Import Java.net.URL;
Import Java.net.URLClassLoader;


/**
 * @ Writer: Yh.zeng
 * @ Write Time: 2017-12-3 pm 2:26:59
 * @ file Description: Todo/
 public
class Test {

	public static void Main (string args[]) {
        string fileurlstring = new File ("D:\\loader"). Touri (). toString ();
        fileurlstring = Fileurlstring.replaceall ("!/", "%21/");
		try {
			ClassLoader ClassLoader = new URLClassLoader (new Url[]{new URL (fileurlstring)});
			Class Helloworldclazz = Classloader.loadclass ("Terry.codex.HelloWorld");
			Object HelloWorld = Helloworldclazz.newinstance ();
			Method method = Helloworld.getclass (). GetMethod ("SayHello", null);
			Method.invoke (HelloWorld, null);
		catch (Exception E1) {
			//TODO auto-generated catch block
			e1.printstacktrace ();
		}
	}
}

Demo See: Https://github.com/zengyh/CodeLibary/blob/master/src/clazzloader/UrlClassLoaderTest.java