java学习笔记—HttpServletResponse（23）

public void doGet(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {
response.setCharacterEncoding("utf-8");
request.setCharacterEncoding("utf-8");
response.setContentType("text/html;charset=utf-8");
PrintWriter out = response.getWriter();
// 获取客户端信息
out.println("getMethod(): "+request.getMethod()+"<br/>");
out.println("getRequestURL(): "+request.getRequestURL()+"<br/>");
out.println("getRequestURI(): "+request.getRequestURI()+"<br/>");
out.println("getProtocol(): "+request.getProtocol()+"<br/>");
out.println("getQueryString(): "+request.getQueryString()+"<br/>");
out.println("getRemoteAddr(): "+request.getRemoteAddr()+"<br/>");
out.println("getRemoteHost(): "+request.getRemoteHost()+"<br/>");
out.println("getRemotePort(): "+request.getRemotePort()+"<br/>");
out.println("getServletPath(): "+request.getServletPath()+"<br/>");
out.println("getContextPath(): "+request.getContextPath()+"<br/>");
}

public void doGet(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {
response.setCharacterEncoding("utf-8");
request.setCharacterEncoding("utf-8");
response.setContentType("text/html;charset=utf-8");
PrintWriter out = response.getWriter();
// 获取客户端信息
out.println("getLocalAddr(): " + request.getLocalAddr() + "<br/>");
out.println("getLocalName(): " + request.getLocalName() + "<br/>");
out.println("getLocalPort(): " + request.getLocalPort() + "<br/>");
}

public void doGet(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {
        // 获取用户的请求的参数
        String name = request.getParameter("name");
        String psw = request.getParameter("password");
        // 判断用户输入的信息
        if(name != null && psw != null && "jack".equals(name) 
&& "root".equals(psw)){
            // 登陆成功需要将用户信息传递给欢迎页面
            request.setAttribute("name", name);
            // 登陆成功将页面转发到欢迎页面
            request.getRequestDispatcher("/demo2")
.forward(request, response);
        }else{
         request.getRequestDispatcher("/regist.html")
.forward(request, response);
        }
}

public void doGet(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {
        response.setCharacterEncoding("utf-8");
        request.setCharacterEncoding("utf-8");
        response.setContentType("text/html;charset=utf-8");
        PrintWriter out = response.getWriter();
        // 获取转发过来的数据
        String name = (String) request.getAttribute("name");
        out.println("欢迎光临:"+name);
    }

1.    实现方式不同
转发  request.getRequestDispatcher("/regist.html").forward(request, response);
重定向 response.sendRedirect(“/day07/regist.html”)
2.    请求次数不同
转发只发送一次请求
重定向发送2次请求
3.    地址栏变化不同
转发地址栏不变
重定向地址栏变化
4. 转发的时候可以通过request对象携带数据。

如果该路径是给服务器使用的，那么/代表当前网站的根目录。
如果该路径是给浏览器使用的，那么/代表当前Tomcat的webapps目录。