com.omricat.yacc.data.model.CurrencyDataset.java Source code

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Here is the source code for com.omricat.yacc.data.model.CurrencyDataset.java

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/*
 * Copyright 2014 Omricat Software
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.omricat.yacc.data.model;

import com.fasterxml.jackson.annotation.JsonCreator;
import com.fasterxml.jackson.annotation.JsonProperty;

import org.jetbrains.annotations.NotNull;

import java.util.Collections;
import java.util.Set;

import rx.Observable;

import static com.google.common.base.Preconditions.checkArgument;
import static com.google.common.base.Preconditions.checkNotNull;

/**
 * Immutable class to hold a collection of {@link com.omricat.yacc.data.model
 * .Currency} objects and a timestamp indicating when the currencies were last
 * updated.
 * <p/>
 * <strong>Note:</strong> despite the name, this class <strong>does
 * not</strong> implement {@link java.util.Set}.
 *
 */
public class CurrencyDataset {

    public static final String TIMESTAMP = "timestamp";
    public static final String CURRENCIES = "currencies";

    // lastUpdatedTimestamp is a unix epoch timestamp
    @JsonProperty(TIMESTAMP)
    private final long lastUpdatedTimestamp;

    @JsonProperty(CURRENCIES)
    private final Set<Currency> currencies;

    /**
     * Instantiates a currencies list object.
     * @param currencies array of {@link com.omricat.yacc.data.model.Currency}
     *                   objects. May be empty, but not null.
     * @param lastUpdatedTimestamp unix epoch timestamp indicating the last
     *                             time the list of currencies was updated.
     *                             Must be non-negative.
     */
    @JsonCreator
    public CurrencyDataset(@JsonProperty(CURRENCIES) @NotNull final Set<Currency> currencies,
            @JsonProperty(TIMESTAMP) final long lastUpdatedTimestamp) {
        checkArgument(lastUpdatedTimestamp >= 0);
        this.currencies = Collections.unmodifiableSet(checkNotNull(currencies));
        this.lastUpdatedTimestamp = lastUpdatedTimestamp;
    }

    public Set<Currency> getCurrencies() {
        return currencies;
    }

    public long getLastUpdatedTimestamp() {
        return lastUpdatedTimestamp;
    }

    public Observable<Currency> asObservable() {
        return Observable.from(getCurrencies());
    }

    @Override
    public final boolean equals(final Object o) {
        if (this == o)
            return true;
        if (!(o instanceof CurrencyDataset))
            return false;

        CurrencyDataset that = (CurrencyDataset) o;

        if (lastUpdatedTimestamp != that.lastUpdatedTimestamp)
            return false;
        if (!currencies.equals(that.currencies))
            return false;

        return true;
    }

    @Override
    public final int hashCode() {
        int result = currencies != null ? currencies.hashCode() : 0;
        result = 31 * result + (int) (lastUpdatedTimestamp ^ (lastUpdatedTimestamp >>> 32));
        return result;
    }

    public final static CurrencyDataset EMPTY = new CurrencyDataset(Collections.<Currency>emptySet(), 0);
}