com.subitarius.domain.License.java Source code

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Here is the source code for com.subitarius.domain.License.java

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/*
 * License.java
 * Copyright (C) 2011 Meyer Kizner
 * All rights reserved.
 */

package com.subitarius.domain;

import static com.google.common.base.Preconditions.*;

import java.io.IOException;
import java.io.ObjectInputStream;
import java.net.NetworkInterface;
import java.security.InvalidKeyException;
import java.security.PrivateKey;
import java.security.SignatureException;
import java.util.Iterator;
import java.util.Set;

import javax.persistence.Column;
import javax.persistence.ElementCollection;
import javax.persistence.Entity;
import javax.persistence.JoinColumn;
import javax.persistence.ManyToOne;
import javax.persistence.Transient;

import com.google.common.collect.Iterators;
import com.google.common.primitives.Longs;

@Entity
public class License extends SignedEntity {
    private static final long serialVersionUID = -2191719056095886874L;

    private Team team;

    private Set<Long> macAddresses;

    /**
     * This constructor should only be invoked by the JPA provider.
     */
    protected License() {
    }

    public License(Team team, Set<Long> macAddresses, PrivateKey privateKey)
            throws InvalidKeyException, SignatureException {
        checkNotNull(privateKey);
        setTeam(team);
        setMacAddresses(macAddresses);
        sign(privateKey);
    }

    @ManyToOne
    @JoinColumn(nullable = false, updatable = false)
    public Team getTeam() {
        return team;
    }

    protected void setTeam(Team team) {
        checkNotNull(team);
        this.team = team;
    }

    @ElementCollection
    @Column(nullable = false, updatable = false)
    protected Set<Long> getMacAddresses() {
        return macAddresses;
    }

    protected void setMacAddresses(Set<Long> macAddresses) {
        checkNotNull(macAddresses);
        for (long mac : macAddresses) {
            // valid range of six-byte MAC address
            checkArgument(mac >= 0);
            checkArgument(mac < 0x0001000000000000L);
        }
        this.macAddresses = macAddresses;
    }

    public boolean validate() throws IOException {
        Iterator<NetworkInterface> i1 = Iterators.forEnumeration(NetworkInterface.getNetworkInterfaces());
        while (i1.hasNext()) {
            NetworkInterface iface = i1.next();
            byte[] macBytes = new byte[8];
            System.arraycopy(iface.getHardwareAddress(), 0, macBytes, 2, 6);
            long mac = Longs.fromByteArray(macBytes);
            if (macAddresses.contains(mac)) {
                return true;
            }
        }
        return false;
    }

    @Transient
    @Override
    public byte[] getBytes() {
        byte[] idBytes = getIdBytes();
        byte[] teamBytes = team.getIdBytes();
        // XOR all MACs together to prevent the order from affecting the hash
        long macBytes = 0;
        for (long mac : macAddresses) {
            macBytes ^= mac;
        }
        return DistributedEntity.merge(idBytes, teamBytes, Longs.toByteArray(macBytes));
    }

    @Override
    public int hashCode() {
        final int prime = 31;
        int result = 1;
        result = prime * result + ((macAddresses == null) ? 0 : macAddresses.hashCode());
        result = prime * result + ((team == null) ? 0 : team.hashCode());
        return result;
    }

    @Override
    public boolean equals(Object obj) {
        if (this == obj) {
            return true;
        }
        if (obj == null) {
            return false;
        }
        if (!(obj instanceof License)) {
            return false;
        }
        License other = (License) obj;
        if (macAddresses == null) {
            if (other.macAddresses != null) {
                return false;
            }
        } else if (!macAddresses.equals(other.macAddresses)) {
            return false;
        }
        if (team == null) {
            if (other.team != null) {
                return false;
            }
        } else if (!team.equals(other.team)) {
            return false;
        }
        return true;
    }

    private void readObject(ObjectInputStream ois) throws IOException, ClassNotFoundException {
        ois.defaultReadObject();
        setTeam(team);
        setMacAddresses(macAddresses);
    }
}