如何编写同时使用XML和JSON的servlet程序？

import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.PrintWriter;

public class XMLJSONServlet extends HttpServlet {
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws IOException {
        // 设置响应类型为XML
        response.setContentType("application/xml");
        
        // 解析XML数据
        // ...
        
        // 处理请求
        // ...
        
        // 生成XML响应
        String xmlResponse = "<response><message>Hello, XML!</message></response>";
        
        // 发送响应
        PrintWriter out = response.getWriter();
        out.print(xmlResponse);
        out.flush();
    }
    
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws IOException {
        // 设置响应类型为JSON
        response.setContentType("application/json");
        
        // 解析JSON数据
        // ...
        
        // 处理请求
        // ...
        
        // 生成JSON响应
        String jsonResponse = "{\"message\": \"Hello, JSON!\"}";
        
        // 发送响应
        PrintWriter out = response.getWriter();
        out.print(jsonResponse);
        out.flush();
    }
}