AbstractIdAndVersion.java

package com.aconex.scrutineer;

import java.io.IOException;
import java.io.ObjectOutputStream;

import org.apache.commons.lang.builder.CompareToBuilder;
import org.apache.commons.lang.builder.HashCodeBuilder;


public abstract class AbstractIdAndVersion implements IdAndVersion {

	private final long version;

	protected AbstractIdAndVersion(long version) {
        this.version = version;
	}

	@Override
    public long getVersion() {
        return version;
    }

    @Override
    public boolean equals(Object obj) {
        if (!(obj instanceof AbstractIdAndVersion)) {
            return false;
        }
        AbstractIdAndVersion other = (AbstractIdAndVersion) obj;
        return this.compareTo(other) == 0;
    }

    @Override
    public int hashCode() {
        return appendId(new HashCodeBuilder()).append(version).toHashCode();
    }

	@Override
    public String toString() {
        return getId() + ":" + getVersion();
    }

    @Override
    public int compareTo(IdAndVersion other) {
        return appendId(new CompareToBuilder(), other).append(version, other.getVersion()).toComparison();
    }

	@Override
    public final void writeToStream(ObjectOutputStream objectOutputStream) throws IOException {
    	writeId(objectOutputStream);
    	objectOutputStream.writeLong(version);
    }

    protected abstract HashCodeBuilder appendId(HashCodeBuilder appender);
    protected abstract CompareToBuilder appendId(CompareToBuilder appender, IdAndVersion other);
    protected abstract void writeId(ObjectOutputStream objectOutputStream) throws IOException;
}