request和response复习总结

来源：互联网发布：iphone数据流量开关编辑：程序博客网时间：2024/06/06 09:42

package com.request_response;

import java.io.IOException;
import java.io.PrintWriter;
import java.net.URLDecoder;
import java.net.URLEncoder;
import java.util.Arrays;
import java.util.Map;
import java.util.Map.Entry;

import javax.servlet.ServletException;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class RR extends HttpServlet {

   /**
   * Destruction of the servlet. <br>
   */
   public void destroy() {
       super.destroy(); // Just puts "destroy" string in log
       // Put your code here
   }

   public void doGet(HttpServletRequest request, HttpServletResponse response)
           throws ServletException, IOException {

       this.doPost(request, response);
   }

   public void doPost(HttpServletRequest request, HttpServletResponse response)
           throws ServletException, IOException {

       //重要的参数方法
       try {
           importantFun(request, response);
       } catch (Exception e) {
           e.printStackTrace();
       }

       /**
       * request对象相关
       *
       */
       // 1. 获取请求方式 post get
       String method = request.getMethod();

       // 2. 获取协议
       String protocol = request.getProtocol();

       // 3. 获取请求资源
       String requestUrl = request.getRequestURL().toString();

       // 4. 获取工程名
       String projectName = request.getContextPath();

       // 5. 获取请求资源路径
       String projectResource = request.getRequestURL().substring(request.getContextPath().length());

       // 6. 获取请求的IP地址
       String requestIp = request.getRemoteAddr();

       // 7. 获取请求的端口
       int requestPort = request.getRemotePort();

       // 8. 获取请求的主机
       String requestHost = request.getRemoteHost();

       // 9.
       String requestUser = request.getRemoteUser();

       System.out.println("\n\n\nRemoteUser = " + requestUser);













       /*response.setContentType("text/html");
       PrintWriter out = response.getWriter();
       out.println("<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01 Transitional//EN\">");
       out.println("<HTML>");
       out.println(" <HEAD><TITLE>A Servlet</TITLE></HEAD>");
       out.println(" <BODY>");
       out.print("    This is ");
       out.print(this.getClass());
       out.println(", using the POST method");
       out.println(" </BODY>");
       out.println("</HTML>");
       out.flush();
       out.close();*/
   }

   /**
   * 重要的方法
   * @param request
   * @param response
   * @throws Exception
   */
   public void importantFun(HttpServletRequest request, HttpServletResponse response) throws Exception{

       //response对象常用方法

       //1. 设置状态码
       response.setStatus(302); //重定向状态码

       //2. 设置响应头信息
       response.setHeader("Location", request.getContextPath()+"/login.html"); //配合方法1 设置重定向路径

       //3. 重定向
       try {
           response.sendRedirect(request.getContextPath()+"/login.html"); //方法1 和方法2的综合
       } catch (IOException e) {
           e.printStackTrace();
       }

       //4. 通过response对象设置响应头信息, 设置5秒中自动跳转到新页面
       response.setHeader("refresh", "5; url="+request.getContextPath()+"/login.html");
       response.setHeader("content-type", "text/html;charset=utf-8");


       //5. response获取字符输出流
       PrintWriter out = response.getWriter();

       //6. response获取字节输出流
       ServletOutputStream outputStream = response.getOutputStream();

       //7. 设置响应文件类型 MIME
       response.setContentType("text/html;charset=utf-8"); //代替 response.setCharacterEncoding("utf-8");

       //8. 设置输入编码方式
       response.setCharacterEncoding("utf-8");


       //request对象的常用方法

       //1. 获取页面传值
       String name = request.getParameter("name");

       //2. 获取多选框传过来的值
       String[] values = request.getParameterValues("interest");

       //3. 获取页面上所有的数据
       Map<String, String[]> parameterMap = request.getParameterMap();
       for (Entry<String, String[]> string : parameterMap.entrySet()) {
           //将数组转换为字符串
           Arrays.toString(string.getValue());
       }

       //4. 获取请求方式
       String method = request.getMethod();

       //5. 获取协议
       String protocol = request.getProtocol();

       //6. 获取请求资源路径
       StringBuffer requestURL = request.getRequestURL();
       String requestURI = request.getRequestURI();
       String requestResource = request.getRequestURI().substring(request.getContextPath().length());

       //7. 获取主机ip
       String ip = request.getRemoteAddr();

       //8. 获取工程虚拟路径名
       String contextPath = request.getContextPath();

       //9. 获取执行的请求头信息，获取请求头信息
       String referer = request.getHeader("referer"); //防盗链设置，可以跟去头信息是否以服务器ip作为请求头信息来判断、该请求的链接地址
       if(referer != null && referer.startsWith("http://localhost")){
           //有效
       }

       //10. 获取客户端浏览器类型
       String agent = request.getHeader("User-Agent");

       //11. post方式请求乱码处理
       request.setCharacterEncoding("utf-8");

       //12. get方式请求乱码处理编码转换/ 服务器默认解码类型为 iso-8859-1
       String parameter = request.getParameter("name");
       // 方法1
       parameter = URLEncoder.encode(parameter, "iso-8859-1"); //先编码
       parameter = URLDecoder.decode(parameter, "utf-8"); //再按照utf-8解码

       //方法2 利用字符串提供的编码设置**********************
       parameter = new String(parameter.getBytes("iso-8859-1"), "utf-8");

       request.setAttribute("key", "value");

       request.getRequestDispatcher("url").forward(request, response);

       //转发可以通过request携带数据，重定向为什么不能携带数据？
       //因为重定向response是通知浏览器，进行的二次访问服务器。此时请求对象已经销毁了。

       /**
       * 转发：属于服务器内部跳转路径不需要写工程名
       * 重定向：属于二次请求，请求路径需要添加工程名
       */

   }

   /**
   * Initialization of the servlet. <br>
   *
   * @throws ServletException if an error occurs
   */
   public void init() throws ServletException {
       // Put your code here
   }

}

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