jsp中调用java编译器的有关问题

        JavaCompiler compiler = ToolProvider.getSystemJavaCompiler();        int results = compiler.run(null, null, null, "C:\\Program Files\\Apache Software   Foundation\\Tomcat 6.0\\webapps\\test\\JavaProgramming.java");        out.println((results == 0)?"编译成功":"编译失败");        Runtime run = Runtime.getRuntime();                Process p = run.exec("java JavaProgramming");                BufferedInputStream in = new BufferedInputStream(p.getInputStream());        BufferedReader br = new BufferedReader(new InputStreamReader(in));        String s = br.readLine();        while (s.equals("hello"))        out.println("the program is correct");