- 修改响应
既然我们能通过Filter修改
HttpServletRequest
,自然也能修改HttpServletResponse
,因为这两者都是接口。我们来看一下在什么情况下我们需要修改
HttpServletResponse
。假设我们编写了一个Servlet,但由于业务逻辑比较复杂,处理该请求需要耗费很长的时间:
@WebServlet(urlPatterns = "/slow/hello") public class HelloServlet extends HttpServlet { protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { resp.setContentType("text/html"); // 模拟耗时1秒: try { Thread.sleep(1000); } catch (InterruptedException e) { } PrintWriter pw = resp.getWriter(); pw.write("<h1>Hello, world!</h1>"); pw.flush(); } }