com.almende.eve.transport.tokens.TokenStore.java Source code

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Here is the source code for com.almende.eve.transport.tokens.TokenStore.java

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/*
 * Copyright: Almende B.V. (2014), Rotterdam, The Netherlands
 * License: The Apache Software License, Version 2.0
 */
package com.almende.eve.transport.tokens;

import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import java.util.logging.Level;
import java.util.logging.Logger;

import org.joda.time.DateTime;

import com.almende.util.uuid.UUID;

/**
 * Simple token system: Each outbound call gets a token, which is newly
 * generated each hour. Last 5 tokens are
 * kept in memory. If remote peer wants to check if this host has actually send
 * the call, it can request a resend of the
 * token at time X.
 * 
 * 
 * @author ludo
 * 
 */
public final class TokenStore {
    private static final Logger LOG = Logger.getLogger(TokenStore.class.getCanonicalName());
    private static final int SIZE = 5;
    private Map<String, String> tokens = new ConcurrentHashMap<String, String>();
    private DateTime last = DateTime.now();

    /**
     * Instantiates a new token store.
     */
    public TokenStore() {
    };

    /**
     * Gets the.
     * 
     * @param time
     *            the time
     * @return the string
     */
    public String get(final String time) {
        try {
            return tokens.get(time);
        } catch (final Exception e) {
            LOG.log(Level.WARNING, "Exception during TokenStore get:", e);
            return null;
        }
    }

    /**
     * Creates the.
     * 
     * @return the token ret
     */
    public TokenRet create() {
        TokenRet result;
        if (tokens.size() == 0 || tokens.get(last.toString()) == null || last.plus(3600000).isBeforeNow()) {
            final DateTime now = DateTime.now();
            final String token = new UUID().toString();
            result = new TokenRet(token, now);
            tokens.put(now.toString(), token);
            last = now;

            if (tokens.size() > SIZE + 2) {
                DateTime oldest = last;
                for (final String time : tokens.keySet()) {
                    try {
                        if (DateTime.parse(time).isBefore(oldest)) {
                            oldest = DateTime.parse(time);
                        }
                    } catch (final Exception e) {
                        LOG.log(Level.WARNING, "Failed in eviction of tokens:", e);
                    }
                }
                tokens.remove(oldest.toString());
            }
        } else {
            result = new TokenRet(tokens.get(last.toString()), last);
        }
        return result;
    }
}