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package com.yiwei.utils;
import java.util.ArrayList;
import javax.servlet.http.HttpSession;
public class Token {
private static final String TOKEN_LIST_NAME = "tokenList";
public static final String TOKEN_STRING_NAME = "token";
private static ArrayList getTokenList(HttpSession session) {
Object obj = session.getAttribute(TOKEN_LIST_NAME);
if (obj != null) {
return (ArrayList) obj;
} else {
ArrayList tokenList = new ArrayList();
session.setAttribute(TOKEN_LIST_NAME, tokenList);
return tokenList;
}
}
private static void saveTokenString(String tokenStr, HttpSession session) {
ArrayList tokenList = getTokenList(session);
tokenList.add(tokenStr);
session.setAttribute(TOKEN_LIST_NAME, tokenList);
}
private static String generateTokenString() {
return new Long(System.currentTimeMillis()).toString();
}
/** */
/**
*
* Generate a token string, and save the string in session, then return the
* token string.
*
*
*
* @param HttpSession
*
* session
*
* @return a token string used for enforcing a single request for a
* particular transaction.
*
*/
public static String getTokenString(HttpSession session) {
String tokenStr = generateTokenString();
saveTokenString(tokenStr, session);
return tokenStr;
}
/** */
/**
*
* check whether token string is valid. if session contains the token
* string, return true.
*
* otherwise, return false.
*
*
*
* @param String
*
* tokenStr
*
* @param HttpSession
*
* session
*
* @return true: session contains tokenStr; false: session is null or
* tokenStr is id not in session
*
*/
public static boolean isTokenStringValid(String tokenStr, HttpSession session) {
boolean valid = false;
if (session != null) {
ArrayList tokenList = getTokenList(session);
if (tokenList.contains(tokenStr)) {
valid = true;
tokenList.remove(tokenStr);
}
}
return valid;
}
}
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