Since the GetCookies method of HTTPSERVLETREQUEST returns a Cookie object array, therefore usually uses a loop to access this array to find a specific name, and then check its value with getValue. GetPath / SetPath Gets / Sets the path to Cookies. If the path is not specified, the cookie will return to all the pages in the current page where the current page is located and its subdirectory. The method here can be used to set some more general conditions. For example, someCookie.SetPath ("/"), at which time all pages on the server can receive the cookie. GetSecure / SetSecure Gets / Sets a Boolean value that represents whether cookies can only be sent by encrypted connections (ie SSL). GetValue / SetValue Gets the value of / set the cookie. As mentioned earlier, the names and values are actually two aspects we have always cared. However, there are also some exceptions, such as using the name as a logical tag (that is, if the name exists, it means true. GetVersion / SetVersion Gets / Sets the protocol version of the cookies. The default version 0 (complies with the original Netscape specification); version 1 follows RFC 2109, but has not been widely supported. 9.2.3 Setting Cookie cookies in your response head to join the set-cookie response head with the AddCookie method of HttpservletResponse. Here is an example: cookie usercookie = New cookie ("User", "UID1234"); response.addcookie (userCookie); 9.2.4 Read Save to the client to send cookies to the client, first create a cookie, Then send a SET-Cookie HTTP response head with AddCookie. These contents have been described above in Top 2.1. The getCookies method that calls HTTPSERVLETREQUEST when reading cookies from the client. This method returns an array of cookie objects corresponding to content in the HTTP request header. After getting this array, it is generally used to access the individual elements in the loop, call GetName to check the names of each cookie until the target cookie is found. Then, the GetValue is then called to this target cookie, and other processing is performed according to the result. The above processing process often encounters, and provides a getCookieValue method for the convenience meter. Just give the cookie object array, the cookie name, and defaults, the getCookieValue method returns a cookie value that matches the specified name. If you can't find the specified cookie, return the default value. 9.3 Several Cookie Tools Functions are several tool functions. Although these functions are simple, it is useful when dealing with cookies. 9.3.1 Getting a cookie value of the specified name This function is part of ServletUtilities.java. GetCookieValue sequentially accesses the various elements of the cookie object array via a loop, finds a cookie for specifying the name, if you find it, return the value of the cookie; otherwise, return the default value given in the parameter. GetCookieValue can simplify the extraction of the cookie value to a certain extent.
public static String getCookieValue (Cookie [] cookies, String cookieName, String defaultValue) {for (int i = 0; i package hall; import java.io. *; import javax.servlet *;. import javax.servlet.http *;. import java.net *;. public class SearchEnginesFrontEnd extends HttpServlet {public void doGet (HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {Cookie [] cookies = request.getCookies (); String searchString = ServletUtilities.getCookieValue (cookies, "searchString", "Java Programming"); String numResults = ServletUtilities.getCookieValue (cookies, "numResults", "10" ); String searchEngine = ServletUtilities.getCookieValue (cookies, "searchEngine", "google"); response.setContentType ( "text / html"); PrintWriter out = response.getWriter (); String title = "Searching the Web"; out .println (servletutilities.headwithtitle (title) Searching the Web \N " " \ N " "
