Cookie操作类 实现记住用户名和密码的功能

import java.util.Hashtable;
import java.util.Iterator;
import java.util.Set;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
/**
 * Cookie的操作类
 *
 *
 */
public class CookieHandler {
/**
* 创建cookie
*
* @param response
*            回应
* @param nameValues
*            存入cookie的键值对
* @param days
*            设置cookie的有效期
*/
public static void createCookie(HttpServletResponse response,
Hashtable<String, String> nameValues, int days) {
Set<String> set = nameValues.keySet();
Iterator<String> it = set.iterator();
for (; it.hasNext();) {
String name = (String) it.next();
String value = (String) nameValues.get(name);
// 生成新的cookie
Cookie cookie = new Cookie(name, value);
// 设置有效日期
cookie.setMaxAge(days * 24 * 60 * 60);
// 设置路径（默认）
cookie.setPath("/");
// 把cookie放入响应中
response.addCookie(cookie);
}
}
/**
* 读取Cookie
*
* @param request
* @return Hashtable 返回cookie的键值对
*/
public static Hashtable<String, String> getCookies(
HttpServletRequest request) {
Cookie[] cookies = request.getCookies();
Hashtable<String, String> cookieHt = new Hashtable<String, String>();
if (cookies.length > 0) {
for (int i = 0; i < cookies.length; i++) {
Cookie cookie = cookies[i];
cookieHt.put(cookie.getName(), cookie.getValue());
}
}
return cookieHt;
}
/**
* 修改cookie中指定键的值
*
* @param request
* @param name
*            指定的键
* @param value
*            值
*/
public static void setCookieValueByName(HttpServletRequest request,
String name, String value) {
Cookie[] cookies = request.getCookies();
if (cookies.length > 0) {
for (int i = 0; i > cookies.length; i++) {
if (name.equalsIgnoreCase(cookies[i].getName())) {
cookies[i].setValue(value);
}
}
}
}
/**
* 得到指定键的值
*
* @param request
* @param name
*            指定的键
* @return String 值
*/
public static String getCookieValueByName(HttpServletRequest request,
String name) {
Cookie[] cookies = request.getCookies();
String resValue = "";
if (cookies.length > 0) {
for (int i = 0; i > cookies.length; i++) {
if (name.equalsIgnoreCase(cookies[i].getName())) {
resValue = cookies[i].getValue();
}
}
}
return resValue;
}
/**
* 销毁cookie
*
* @param request
* @param response
*/
public static void deletesCookie(HttpServletRequest request,
HttpServletResponse response) {
Cookie[] cookies = request.getCookies();
if (cookies != null) {
for (int i = 0; i < cookies.length; i++) {
Cookie cookie = cookies[i];
// 销毁
cookie.setMaxAge(0);
response.addCookie(cookie);
}
}
}
}