Target,Retention xml파일에 FileOutputStream이용하여 내용넣기

import java.lang.annotation.*;
import java.lang.reflect.*;
import java.io.*;

@Target(value=ElementType.METHOD)
@Retention(value=RetentionPolicy.RUNTIME)
@interface WebServlet{
 String urlPatterns();
}
class ServletTest{
 @WebServlet(urlPatterns="/now")
 void doGet(){
 }
}
class A{
 public static void main(String args[]) throws Exception{
 Method m=ServletTest.class.getDeclaredMethod("doGet");
 WebServlet ws=m.getAnnotation(WebServlet.class);
 String pattern=ws.urlPatterns();
 StringBuffer buffer=new StringBuffer();
 buffer.append("<servlet-mapping>");
 buffer.append("<url-pattern>"+pattern+"</url-pattern>");
 buffer.append("</servlet-mapping>");
 String s=buffer.toString();
 FileOutputStream out=new FileOutputStream("c:/web.xml");
 out.write(s.getBytes());
 out.flush();
 }
}