Question

servlet request请求对象常用方法总结

Answer 1

1. request请求对象常用方法：
   public void doPost(HttpServletRequest request, HttpServletResponse response)
   throws ServletException, IOException {
   response.setContentType("text/html; charset = utf-8");
   this.response = response;
   out = this.response.getWriter();
   println("<ol>");
   //1. 获取请求方式、处理乱码问题
   String method = request.getMethod();
   
   //servletRequest中的方法
   request.setCharacterEncoding("utf-8");
   //1. 获取请求体的编码方式
   String characterEncoding = request.getCharacterEncoding();
   println("getCharacterEncoding = " + characterEncoding);
   
   //2. get body length
   int contentLength = request.getContentLength();
   println("getContentLength = " + contentLength);
   
   //3. MIME type
   String mimeType = request.getContentType();
   println("getContentType = " + mimeType);
   
   //4. 接收请求的接口的 Internet Protocol (IP) 地址
   String ip = request.getLocalAddr();
   println("getLocalAddr = " + ip);
   
   //5. 基于 Accept-Language 头，返回客户端将用来接受内容的首选 Locale 客户端语言环境
   Locale locale = request.getLocale();
   println("getLocale = " + locale);
   
   //6. 所有的语言环境
   Enumeration<Locale> locales = request.getLocales();
   while(locales.hasMoreElements()){
   Locale temp = locales.nextElement();
   println("\n Locales = " + temp);
   }
   
   //7. 接收请求的 Internet Protocol (IP) 接口的主机名
   String localName = request.getLocalName();
   println("localName = " + localName);
   
   //8. 接收请求的接口的 Internet Protocol (IP) 端口号
   int localPort = request.getLocalPort();
   println("localPort = " + localPort);
   
   //9. 返回请求使用的协议的名称和版本
   String protocol = request.getProtocol();
   println("protocol = " + protocol);
   
   //10. 读取请求正文信息
   BufferedReader reader = request.getReader();
   println("getReader = " + reader.toString());
   
   //11. 发送请求的客户端
   String remoteAddr = request.getRemoteAddr();
   println("RemoteAddr = " + remoteAddr);
   
   //12. 发送请求的客户主机
   String remoteHost = request.getRemoteHost();
   println("RemoteHost = " + remoteHost);
   
   //13. 发送请求的客户主机端口
   int remotePort = request.getRemotePort();
   println("RemotePort = " + remotePort);
   
   //14. 返回用于发出此请求的方案名称，例如：http 、 https 、 ftp
   String scheme = request.getScheme();
   println("Scheme = " + scheme);
   
   //15. 返回请求被发送到的服务器的主机名。它是Host头值":"(如果有)之前的那部分的值。 或者解析服务器名称或服务器的IP地址
   String serverName = request.getServerName();
   println("ServerName = " + serverName);
   
   //16. 返回请求被发送到的端口。他是"Host"头值":" （如果有）之后的那部分的值，或者接受客户端连接的服务器端口。
   int serverPort = request.getServerPort();
   println("ServerPort = " + serverPort);
   
   //17. 返回一个boolean值，指示此请求是否是使用安全通道(比如HTTPS) 发出的。
   boolean secure = request.isSecure();
   println("isSecure = " + secure);
   
   //以上方法为 ServletRequest 接口提供的
   
   //以下方法为 HttpServletRequest 接口提供的
   
   /*
   * 18. 返回用于保护servlet的验证方法名称。 所有的servlet容器都支持
   * basic、 form和client certificate验证, 并且可能还支持digest验证
   */
   String authType = request.getAuthType();
   println("authType = " + authType);
   
   //19. getDateHeader ??
   request.getDateHeader("");
   
   //20. 返回请求头包含的所有头名称的枚举。
   Enumeration<String> headerNames = request.getHeaderNames();
   println("<hr/>");
   while(headerNames.hasMoreElements()){
   String name = headerNames.nextElement();
   println(" headerNmea = " + name + ";　　　getHeader = " + request.getHeader(name));
   }
   
   println("<hr/>");
   //21. 以int的形式返回指定请求头的值。 ???
   request.getIntHeader("123");
   
   //22. 返回与客户端发出此请求时发送的URL相关联的额外路径信息。
   String pathInfo = request.getPathInfo();
   println("PathInfo = " + pathInfo);
   
   //23. 返回包含在请求RUL中路径后面的查询字符串。如果没有查询字符串返回null
   String remoteUser = request.getRemoteUser();
   println("RemoteUser = " + remoteUser);
   
   //24. 返回客户端制定的回话ID
   String requestedSessionId = request.getRequestedSessionId();
   println("requestSessionId = " + requestedSessionId);
   
   //25. 返回请求调用servlet的URL部分
   String servletPath = request.getServletPath();
   println("servletPath = " + servletPath);
   
   //26. 返回与此请求关联的当前HttpSession，如果没有当前会话并且参数为true,则返回一个新会话。
   HttpSession session = request.getSession(true);
   println("getSession(true) = " + session);
   
   //27. 返回包含当前已经过验证的用户的名称的java.security.Principal对象。如果用户没有经过验证，则该方法返回null
   Principal userPrincipal = request.getUserPrincipal();
   println("userPrincipal = " + userPrincipal);
   
   //28. 检查会话的id是否作为Cook进入的
   boolean sessionIdFromCookie = request.isRequestedSessionIdFromCookie();
   println("sessionIdFromCookie = " + sessionIdFromCookie);
   
   //29. 检查请求的会话ID是否作为请求的URL的一部分进入的
   boolean sessionIdFromURL = request.isRequestedSessionIdFromURL();
   println("sessionIdFormURL = " + sessionIdFromURL);
   
   //30.
   
   println("</ol>");
   out.flush();
   out.close();
   
   }
   
   public void println(Object obj){
   this.response.setContentType("text/html;charset=utf-8");
   try {
   
   out.println("<li>");
   out.println(obj);
   out.println("</li>\n");
   } catch (Exception e) {
   e.printStackTrace();
   }
   }
   
   2. 运行结果
   
   getCharacterEncoding = utf-8
   getContentLength = -1
   getContentType = null
   getLocalAddr = 127.0.0.1
   getLocale = zh_CN
   Locales = zh_CN
   Locales = zh
   Locales = en_US
   Locales = en
   localName = lm.licenses.adobe.com
   localPort = 8080
   protocol = HTTP/1.1
   getReader = org.apache.catalina.connector.CoyoteReader@17b8d3d
   RemoteAddr = 127.0.0.1
   RemoteHost = 127.0.0.1
   RemotePort = 57814
   Scheme = http
   ServerName = localhost
   ServerPort = 8080
   isSecure = false
   authType = null
   headerNmea = host;　　　getHeader = localhost:8080
   headerNmea = user-agent;　　　getHeader = Mozilla/5.0 (Windows NT 6.1; rv:32.0) Gecko/20100101 Firefox/32.0
   headerNmea = accept;　　　getHeader = text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
   headerNmea = accept-language;　　　getHeader = zh-cn,zh;q=0.8,en-us;q=0.5,en;q=0.3
   headerNmea = accept-encoding;　　

   getHeader = gzip, deflate
   headerNmea = cookie;　　　

   getHeader = JSESSIONID=30256CEB48E2BF6050BF6E122635EAC4
   headerNmea = connection;　　　

   getHeader = keep-alive
   PathInfo = null
   RemoteUser = null
   requestSessionId = 30256CEB48E2BF6050BF6E122635EAC4
   servletPath = /req
   getSession(true) = org.apache.catalina.session.StandardSessionFacade@1fcf1ba
   userPrincipal = null
   sessionIdFromCookie = true
   sessionIdFormURL = false