请在 如何以编程方式编译和实例化Java类上查看BalusC的解决方案？为了进行测试，请复制并粘贴以下JSP。我希望BalusC不介意我更改了他的代码。

<%@ page import="java.util.*,java.io.*,javax.tools.*,java.net.*" %><%
System.setOut(new PrintStream(response.getOutputStream()));
// Prepare source somehow. 
String source = "package test; public class Test { static { System.out.println(\"hello\"); } public Test() { System.out.println(\"rickz\"); } }";  
// Save source in .java file. 
File root = new File("/testJava"); 
// On Windows running on C:\, this is C:\testJava. 
File sourceFile = new File(root, "test/Test.java"); 
sourceFile.getParentFile().mkdirs(); 
new FileWriter(sourceFile).append(source).close();  
// Compile source file. 
JavaCompiler compiler = ToolProvider.getSystemJavaCompiler(); 
compiler.run(null, null, null, sourceFile.getPath());  
// Load and instantiate compiled class. 
URLClassLoader classLoader = URLClassLoader.newInstance(new URL[] { root.toURI().toURL() }); 
Class<?> cls = Class.forName("test.Test", true, classLoader); // Should print "hello". 
Object instance = cls.newInstance(); // Should print "world". 
System.out.println(instance); // Should print "test.Test@hashcode". 
if(out != null) return;
%>