javaweb-httpservlet获取客户端发送过来的get数据

public class servletRequest extends HttpServlet {
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        //req获取到客户端发送数据给服务器
        String username = req.getParameter("username");
        //服务端处理完数据后给客户端发送一个响应的数据，以下的格式位html码，或者是文本类型的
        resp.setHeader("Content-Type","text/html;charset=UTF-8");
        PrintWriter writer = resp.getWriter();
        writer.write("欢迎"+username+"访问当前页面");
        writer.close();
    }
}