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");