1. request對象和response對象的原理
?? ?1. request和response對象是由服務器創建的。我們來使用它們
?? ?2. request對象是來獲取請求消息，response對象是來設置響應消息

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2. request對象繼承體系結構：?? ?
?? ?ServletRequest?? ??? ?--?? ?接口
?? ??? ?|?? ?繼承
?? ?HttpServletRequest?? ?-- 接口
?? ??? ?|?? ?實現
?? ?org.apache.catalina.connector.RequestFacade 類(tomcat)

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3. request功能：

? ? ? 1. 獲取請求消息數據

? ? ? ? ? ? ? ?1. 獲取請求行數據
?? ??? ??? ?* GET /day14/demo1?name=zhangsan HTTP/1.1
?? ??? ??? ?* 方法：
?? ??? ??? ??? ?1. 獲取請求方式 ：GET
?? ??? ??? ??? ??? ?* String getMethod() ?
?? ??? ??? ??? ?2. (*)獲取虛擬目錄：/day14
?? ??? ??? ??? ??? ?* String getContextPath()
?? ??? ??? ??? ?3. 獲取Servlet路徑: /demo1
?? ??? ??? ??? ??? ?* String getServletPath()
?? ??? ??? ??? ?4. 獲取get方式請求參數：name=zhangsan
?? ??? ??? ??? ??? ?* String getQueryString()
?? ??? ??? ??? ?5. (*)獲取請求URI：/day14/demo1
?? ??? ??? ??? ??? ?* String getRequestURI():?? ??? ?/day14/demo1
?? ??? ??? ??? ??? ?* StringBuffer getRequestURL() ?:http://localhost/day14/demo1

?? ??? ??? ??? ??? ?* URL:統一資源定位符 ： http://localhost/day14/demo1?? ?中華人民共和國
?? ??? ??? ??? ??? ?* URI：統一資源標識符 : /day14/demo1?? ??? ??? ??? ??? ?共和國
?? ??? ??? ??? ?
?? ??? ??? ??? ?6. 獲取協議及版本：HTTP/1.1
?? ??? ??? ??? ??? ?* String getProtocol()

?? ??? ??? ??? ?7. 獲取客戶機的IP地址：
?? ??? ??? ??? ??? ?* String getRemoteAddr()
?? ??? ??? ??? ?
? ? ?

package cn.itcast.web.request;import javax.servlet.ServletException; import javax.servlet.annotation.WebServlet; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import java.io.IOException;/*** 演示Request對象獲取請求行數據*/@WebServlet("/requestDemo1") public class RequestDemo1 extends HttpServlet {protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {}protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {//1. 獲取請求方式 ：GETString method = request.getMethod();System.out.println(method);//2.(*)獲取虛擬目錄：/day14String contextPath = request.getContextPath();System.out.println(contextPath);//3. 獲取Servlet路徑: /demo1String servletPath = request.getServletPath();System.out.println(servletPath);//4. 獲取get方式請求參數：name=zhangsanString queryString = request.getQueryString();System.out.println(queryString);//5.(*)獲取請求URI：/day14/demo1String requestURI = request.getRequestURI();StringBuffer requestURL = request.getRequestURL();System.out.println(requestURI);System.out.println(requestURL);//6. 獲取協議及版本：HTTP/1.1String protocol = request.getProtocol();System.out.println(protocol);//7. 獲取客戶機的IP地址：String remoteAddr = request.getRemoteAddr();System.out.println(remoteAddr);} }

? ? ? ?

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2. 獲取請求頭數據
?? ??? ??? ?* 方法：
?? ??? ??? ??? ?* (*)String getHeader(String name):通過請求頭的名稱獲取請求頭的值
?? ??? ??? ??? ?* Enumeration<String> getHeaderNames():獲取所有的請求頭名稱

package cn.itcast.web.request;import javax.servlet.ServletException; import javax.servlet.annotation.WebServlet; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import java.io.IOException; import java.util.Enumeration;@WebServlet("/requestDemo2") public class RequestDemo2 extends HttpServlet {protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {}protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {//演示獲取請求頭數據//1.獲取所有請求頭名稱Enumeration<String> headerNames = request.getHeaderNames();//2.遍歷while(headerNames.hasMoreElements()){String name = headerNames.nextElement();//根據名稱獲取請求頭的值String value = request.getHeader(name);System.out.println(name+"---"+value);}} }

?? ??? ??? ?

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package cn.itcast.web.request;import javax.servlet.ServletException; import javax.servlet.annotation.WebServlet; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import java.io.IOException; import java.util.Enumeration;@WebServlet("/requestDemo3") public class RequestDemo3 extends HttpServlet {protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {}protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {//演示獲取請求頭數據:user-agentString agent = request.getHeader("user-agent");//判斷agent的瀏覽器版本if(agent.contains("Chrome")){//谷歌System.out.println("谷歌來了...");}else if(agent.contains("Firefox")){//火狐System.out.println("火狐來了...");}} }

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package cn.itcast.web.request;import javax.servlet.ServletContext; import javax.servlet.ServletException; import javax.servlet.annotation.WebServlet; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import java.io.IOException;@WebServlet("/requestDemo4") public class RequestDemo4 extends HttpServlet {protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {}protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {//演示獲取請求頭數據:refererString referer = request.getHeader("referer");System.out.println(referer);//http://localhost/day14/login.html//防盜鏈if(referer != null ){if(referer.contains("dym_day14")){//正常訪問// System.out.println("播放電影....");response.setContentType("text/html;charset=utf-8");response.getWriter().write("播放電影....");}else{//盜鏈//System.out.println("想看電影嗎？來優酷吧...");response.setContentType("text/html;charset=utf-8");response.getWriter().write("想看電影嗎？來優酷吧...");}}} }

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?3. 獲取請求體數據:
?? ??? ??? ?* 請求體：只有POST請求方式，才有請求體，在請求體中封裝了POST請求的請求參數
?? ??? ??? ?* 步驟：
?? ??? ??? ??? ?1. 獲取流對象
?? ??? ??? ??? ??? ?* ?BufferedReader getReader()：獲取字符輸入流，只能操作字符數據
?? ??? ??? ??? ??? ?* ?ServletInputStream getInputStream()：獲取字節輸入流，可以操作所有類型數

?? ??? ??? ??? ?2. 再從流對象中拿數據

regist.html

<!DOCTYPE html> <html lang="en"> <head><meta charset="UTF-8"><title>注冊頁面</title> </head> <body><form action="/dym_day14/requestDemo5" method="post"><input type="text" placeholder="請輸入用戶名" name="username"><br><input type="text" placeholder="請輸入密碼" name="password"><br><input type="submit" value="注冊"></form></body> </html>

RequestDemo5.java

package cn.itcast.web.request;import javax.servlet.ServletException; import javax.servlet.annotation.WebServlet; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import java.io.BufferedReader; import java.io.IOException;@WebServlet("/requestDemo5") public class RequestDemo5 extends HttpServlet {protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {//獲取請求消息體--請求參數//1.獲取字符流BufferedReader br = request.getReader();//2.讀取數據String line = null;while((line = br.readLine()) != null){System.out.println(line);}}protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {} }

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