使用 HttpServletRequest 对象,操作请求域数据。
使用 HttpServletRequest 对象,完成对请求域数据的设置、获取、删除等操作。
Servlet 代码:
@WebServlet("/demo06")
public class Servlet extends HttpServlet {
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
request.setCharacterEncoding("utf-8");
response.setContentType("text/html;charset=utf-8");
PrintWriter pw = response.getWriter();
pw.print("嗨客网(www.haicoder.net)<br/>");
pw.print("<br/>");
// 请求域中创建键和值
request.setAttribute("user","HaiCoder");
request.setAttribute("password",123);
// 获取请求域中的键和值
pw.write("<h3>获取请求域的键和值</h3>");
String user = (String) request.getAttribute("user");
Integer password = (Integer) request.getAttribute("password");
// 在页面显示
pw.write("用户名:" + user + "<hr/>");
pw.write("密码:" + password + "<hr/>");
// 删除请求域的键和值
pw.write("<h3>删除请求域的键和值</h3>");
request.removeAttribute("user");
// 再次获取请求域中的键和值
pw.write("<h3>再次获取请求域中的键和值</h3>");
user = (String) request.getAttribute("user");
password = (Integer) request.getAttribute("password");
// 页面显示
pw.write("用户名:" + user + "<hr/>");
pw.write("密码:" + password + "<hr/>");
}
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
this.doPost(request, response);
}
}
启动项目,访问 Servlet ,如下图:
以上案例通过 HttpServletRequest 对象,完成对请求域数据的设置、获取、删除等操作。