EndpointObjectHash.java

/*
 * Copyright 2014-2016 CyberVision, Inc.
 *
 * 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 org.kaaproject.kaa.common.hash;

import org.apache.commons.codec.binary.Base64;

import java.io.Serializable;
import java.nio.ByteBuffer;
import java.nio.charset.Charset;
import java.util.Arrays;


/**
 * The class EndpointObjectHash is responsible for hash calculation.
 *
 * @author Andrew Shvayka
 */
public final class EndpointObjectHash implements Serializable {

  private static final Charset UTF8 = Charset.forName("UTF-8");

  private static final long serialVersionUID = 1L;

  private final byte[] data;

  /**
   * Instantiates a new endpoint object hash.
   *
   * @param data the data
   */
  private EndpointObjectHash(byte[] data) {
    super();
    this.data = Arrays.copyOf(data, data.length);
  }

  /**
   * From bytes.
   *
   * @param data the data
   * @return the endpoint object hash
   */
  public static EndpointObjectHash fromString(String data) {
    if (data == null) {
      return null;
    }
    return new EndpointObjectHash(Base64.encodeBase64(data.getBytes(UTF8)));
  }

  /**
   * From bytes.
   *
   * @param data the data
   * @return the endpoint object hash
   */
  public static EndpointObjectHash fromBytes(byte[] data) {
    if (data == null) {
      return null;
    }
    return new EndpointObjectHash(data);
  }

  /**
   * creates EndpointObjectHash using SHA1 algorithm over String representation of an object.
   *
   * @param data the data
   * @return the endpoint object hash
   */
  public static EndpointObjectHash fromSha1(String data) {
    if (data == null) {
      return null;
    }
    return new EndpointObjectHash(Sha1HashUtils.hashToBytes(data));
  }

  /**
   * creates EndpointObjectHash using SHA1 algorithm over binary representation of an object.
   *
   * @param data the data
   * @return the endpoint object hash
   */
  public static EndpointObjectHash fromSha1(byte[] data) {
    if (data == null) {
      return null;
    }
    return new EndpointObjectHash(Sha1HashUtils.hashToBytes(data));
  }

  /**
   * Gets the data of a hash.
   *
   * @return the data
   */
  public byte[] getData() {
    return Arrays.copyOf(data, data.length);
  }

  /**
   * Gets the byte buffer with a hash.
   *
   * @return the data
   */
  public ByteBuffer getDataBuf() {
    return ByteBuffer.wrap(getData());
  }

  /**
   * Checks if objects are binary equal.
   *
   * @param data the data
   * @return true, if successful
   */
  public boolean binaryEquals(byte[] data) {
    return Arrays.equals(this.data, data);
  }

  /* (non-Javadoc)
   * @see java.lang.Object#toString()
   */
  @Override
  public String toString() {
    return Arrays.toString(data);
  }

  /* (non-Javadoc)
   * @see java.lang.Object#hashCode()
   */
  @Override
  public int hashCode() {
    final int prime = 31;
    int result = 1;
    result = prime * result + Arrays.hashCode(data);
    return result;
  }

  /* (non-Javadoc)
   * @see java.lang.Object#equals(java.lang.Object)
   */
  @Override
  public boolean equals(Object obj) {
    if (this == obj) {
      return true;
    }
    if (obj == null) {
      return false;
    }
    if (getClass() != obj.getClass()) {
      return false;
    }
    EndpointObjectHash other = (EndpointObjectHash) obj;
    if (!Arrays.equals(data, other.data)) {
      return false;
    }
    return true;
  }
}