Java/JSP/Cookie — различия между версиями

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Текущая версия на 07:10, 1 июня 2010

Cookie display in a JSP page

<%@ taglib uri="http://java.sun.ru/jstl/core" prefix="c" %>
<html>
<head><title>Cookie display</title></head>
<body>
<h2>Here are all the Available Cookies</h2>
<c:forEach var="cookies" items="${cookie}">
    <strong><c:out value=
        "${cookies.key}"/></strong>: Object=<c:out value="${cookies.value}"/>, value=<c:out value="${cookies.value.value}"/><br />
        
</c:forEach>

</body>
</html>





Deal with the cookie

// cookieReader.jsp
<%@ taglib uri="http://java.sun.ru/jstl/core" prefix="c" %>
<html>
<body>
<c:choose>
  <c:when test="${empty cookie}" >
  <h2>We did not find any cookies in the request</h2>
  </c:when>
  <c:otherwise>
<h2>The name and value of each found cookie</h2>
<c:forEach var="cookieVal" items="${cookie}">
<strong>Cookie name:</strong> <c:out value="${cookieVal.key}" /><br>
<strong>Cookie value:</strong> <c:out value="${cookieVal.value.value}" /><br><br>
</c:forEach>
</c:otherwise>
</c:choose>
</body>
</html>

// cookieSetter.jsp
<jsp:useBean id="cookieBean" class="com.jexp.CookieBean" />
<jsp:setProperty name="cookieBean" property="name"  value="bakedcookie" />
<jsp:setProperty name="cookieBean" property="maxAge"  value="<%=(365*24*60*60) %>" />
<jsp:setProperty name="cookieBean" property="path"  value="<%= request.getContextPath() %>" />
<jsp:setProperty name="cookieBean" property="cookieHeader"  value="<%= response %>" />
<html>
<head><title>Cookie Maker</title></head>
<body>
<h2>Here is information about the new cookie</h2>
Name: <jsp:getProperty name="cookieBean" property="name" /><br>
Value: <jsp:getProperty name="cookieBean" property="value" /><br>
Path: <jsp:getProperty name="cookieBean" property="path" />
</body>
</html>
// put the class file to WEB-INF/classes/com/jexp
//CookieBean.java
package com.jexp;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServletResponse;
public class CookieBean {
  private Cookie cookie = null;
  public CookieBean() {
  }
  public void setName(String name) {
    if (name == null || (name.equals("")))
      throw new IllegalArgumentException("Invalid cookie name set in: "
          + getClass().getName());
    cookie = new Cookie(name, "" + new java.util.Date().getTime());
  }
  public void setValue(String value) {
    if (value == null || (value.equals("")))
      throw new IllegalArgumentException("Invalid cookie value set in: "
          + getClass().getName());
    if (cookie != null)
      cookie.setValue(value);
  }
  public void setMaxAge(int maxAge) {
    if (cookie != null)
      cookie.setMaxAge(maxAge);
  }
  public void setPath(String path) {
    if (path == null || (path.equals("")))
      throw new IllegalArgumentException("Invalid cookie path set in: "
          + getClass().getName());
    if (cookie != null)
      cookie.setPath(path);
  }
  public void setCookieHeader(HttpServletResponse response) {
    if (response == null)
      throw new IllegalArgumentException(
          "Invalid HttpServletResponse set in: "
              + getClass().getName());
    if (cookie != null)
      response.addCookie(cookie);
  }
  public String getName() {
    if (cookie != null)
      return cookie.getName();
    else
      return "unavailable";
  }
  public String getValue() {
    if (cookie != null)
      return cookie.getValue();
    else
      return "unavailable";
  }
  public String getPath() {
    if (cookie != null)
      return cookie.getPath();
    else
      return "unavailable";
  }
}





JSP Create and List Cookie

<%@ page import="java.util.*" %>
<%
  Cookie[] cookies = request.getCookies();
  if (cookies == null)
    cookies = new Cookie[0];
  Date thisVisit = new Date();
  // add data cookie to session
  Cookie c = new Cookie("lastVisit",""+thisVisit);
  response.addCookie(c);
  // add cookie to session
  String name = request.getParameter("name");
  String value = request.getParameter("value");
  Cookie added = null;
  if (name!=null && value!=null && name.length()>0) {
    added = new Cookie(name,value);
    response.addCookie(added);
  }
%>
<HTML>
  <HEAD>
    <TITLE>Cookie List</TITLE>
  </HEAD>
  <BODY>
    <H1>Cookie List</H1>
    This visit: <%= thisVisit %><BR>
    Number of cookies: <%= cookies.length %><BR>
    <H2>Cookies</H2>
    <%
    for (int i=0; i<cookies.length; i++) {
      out.println(cookies[i].getName()+":\t"+
        cookies[i].getValue()+"<BR>");
      // check if added cookie already present
      if (added!=null && added.getName().equals(cookies[i].getName()))
        added = null;
    }
    if (added != null)
      out.println("new cookie: "+added.getName()+":\t"+
        added.getValue()+"<BR>");
    %>
    <H2>New cookie</H2>
    <FORM>
      <P>Name: <INPUT TYPE="TEXT" NAME="name"></P>
      <P>Value: <INPUT TYPE="TEXT" NAME="value"></P>
      <INPUT TYPE="SUBMIT" VALUE="Add new value">
    </FORM>
  </BODY>
</HTML>





JSP: deal with cookie

<%@ page import="javax.servlet.http.Cookie" %>
<html>
<head>
<title>This page leaves a cookie</title>
</head>
<body>
<h1>Cookies</h1>
<%
  Cookie[] allCookies = request.getCookies();
  Cookie ourCookie = null;
  if (allCookies!=null)
  {
    for (int i=0; i<allCookies.length; i++)
    {
      if (allCookies[i].getName().equals("TestCookie"))
        {
          ourCookie = allCookies[i];
        }
    }
  }
  if (ourCookie == null)
  {
    Cookie cookie = new Cookie("TestCookie", "hello from cookie");
    //cookie.setMaxAge(1800);
    //cookie.setDomain("alex:8080");
    cookie.setPath("/");
    response.addCookie(cookie);
%>
    A cookie has been added to your machine!
    <br>Select refresh to see the details of this cookie.
<%
  }
  else
  {
%>
    The following cookie was added earlier to your machine:
    <br>Version: <%=ourCookie.getVersion() %>
    <br>Name: <%=ourCookie.getName() %>
    <br>Value: <%=ourCookie.getValue() %>
    <br>MaxAge: <%=ourCookie.getMaxAge() %>
<%
  }
%>
</body>
</html>





JSP List All Cookie

<%@ page import="java.util.*" %>
<%
  Cookie[] cookies = request.getCookies();
  if (cookies == null)
    cookies = new Cookie[0];
  Date thisVisit = new Date();
  // add data cookie to session
  Cookie c = new Cookie("lastVisit",""+thisVisit);
  response.addCookie(c);
  // add cookie to session
  String name = request.getParameter("name");
  String value = request.getParameter("value");
  Cookie added = null;
  if (name!=null && value!=null && name.length()>0) {
    added = new Cookie(name,value);
    response.addCookie(added);
  }
%>
<HTML>
  <HEAD>
    <TITLE>Cookie List</TITLE>
  </HEAD>
  <BODY>
    <H1>Cookie List</H1>
    This visit: <%= thisVisit %><BR>
    Number of cookies: <%= cookies.length %><BR>
    <H2>Cookies</H2>
    <%
    for (int i=0; i<cookies.length; i++) {
      out.println(cookies[i].getName()+":\t"+
        cookies[i].getValue()+"<BR>");
      // check if added cookie already present
      if (added!=null && added.getName().equals(cookies[i].getName()))
        added = null;
    }
    if (added != null)
      out.println("new cookie: "+added.getName()+":\t"+
        added.getValue()+"<BR>");
    %>
    <H2>New cookie</H2>
    <FORM>
      <P>Name: <INPUT TYPE="TEXT" NAME="name"></P>
      <P>Value: <INPUT TYPE="TEXT" NAME="value"></P>
      <INPUT TYPE="SUBMIT" VALUE="Add new value">
    </FORM>
  </BODY>
</HTML>





Setting a Cookie

//File: createCookie.jsp
<HTML>
    <HEAD>
        <TITLE>Setting a Cookie</TITLE>
    </HEAD>
    <BODY> 
        <H1>Setting a Cookie</H1>
  
        <%
        Cookie cookie1 = new Cookie("message", "Hello!");
        cookie1.setMaxAge(24 * 60 * 60);
        response.addCookie(cookie1); 
        %> 
    
        



== Setting and Reading Cookies ==






   
  <!-- start source code -->
   
    <source lang="java">
<HTML>
    <HEAD>
        <TITLE>Setting and Reading Cookies</TITLE>
    </HEAD>
 
    <BODY
        <%
        Cookie[] cookies = request.getCookies();
        boolean foundCookie = false;
        for(int i = 0; i < cookies.length; i++) { 
            Cookie c = cookies[i];
            if (c.getName().equals("color")) {
                out.println("bgcolor = " + c.getValue());
                foundCookie = true;
            }
        }  
        if (!foundCookie) {
            Cookie c = new Cookie("color", "cyan");
            c.setMaxAge(24*60*60);
            response.addCookie(c); 
        }
        %> 
        >
        <H1>Setting and Reading Cookies</H1>
        This page will set its background color using a cookie.
    </BODY>
</HTML>