【Java】HttpServletResponse类方法简介

1、引言

HttpServlet中有HttpServletRequest类、HttpServletResponse类

?其中HttpServletRequest类主要是get方法

【HttpServletRequest类中的简单方法】

?HttpServletResponse类中便主要是set方法

2、方法

重用的方法如下🌱

3、设置响应状态码

设置为200?

@WebServlet("/Status")
public class StatusServlet extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        resp.setStatus(200);
    }
}

?

设置为404?

@WebServlet("/Status")
public class StatusServlet extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        resp.setStatus(404);
    }
}

很明显，只是设置状态码为404的话，未找到状态的页面并不显示😯

因此我们需要使用setError?

@WebServlet("/Status")
public class StatusServlet extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        resp.sendError(404,"错误页面");
    }
}

4、setHeader?

?利用setHeader方法进行刷新

@WebServlet("/refresh")
public class RefreshServlet extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        resp.setHeader("refresh","1");
        resp.getWriter().write("" + System.currentTimeMillis());
    }
}

打开浏览器，得到下面效果?

5、重定向

?利用状态码302和setHeader，直接重定向到电子科技大学官网

@WebServlet("/redirect")
public class redirect extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        resp.setStatus(302);
        resp.setHeader("Location","https://www.uestc.edu.cn");
    }
}