content: /*
   *  Licensed to the Apache Software Foundation (ASF) under one or more
   *  contributor license agreements.  See the NOTICE file distributed with
   *  this work for additional information regarding copyright ownership.
   *  The ASF licenses this file to You 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.alimama.mdrill.utils.zip;
  
  import static com.alimama.mdrill.utils.zip.ZipConstants.BYTE_MASK;
  
  /**
   * Utility class that represents a two byte integer with conversion
   * rules for the big endian byte order of ZIP files.
   *
   */
  public final class ZipShort implements Cloneable {
      private static final int BYTE_1_MASK = 0xFF00;
      private static final int BYTE_1_SHIFT = 8;
  
      private final int value;
  
      /**
       * Create instance from a number.
       * @param value the int to store as a ZipShort
       * @since 1.1
       */
      public ZipShort (int value) {
          this.value = value;
      }
  
      /**
       * Create instance from bytes.
       * @param bytes the bytes to store as a ZipShort
       * @since 1.1
       */
      public ZipShort (byte[] bytes) {
          this(bytes, 0);
      }
  
      /**
       * Create instance from the two bytes starting at offset.
       * @param bytes the bytes to store as a ZipShort
       * @param offset the offset to start
       * @since 1.1
       */
      public ZipShort (byte[] bytes, int offset) {
          value = ZipShort.getValue(bytes, offset);
      }
  
      /**
       * Get value as two bytes in big endian byte order.
       * @return the value as a a two byte array in big endian byte order
       * @since 1.1
       */
      public byte[] getBytes() {
          byte[] result = new byte[2];
          result[0] = (byte) (value & BYTE_MASK);
          result[1] = (byte) ((value & BYTE_1_MASK) >> BYTE_1_SHIFT);
          return result;
      }
  
      /**
       * Get value as Java int.
       * @return value as a Java int
       * @since 1.1
       */
      public int getValue() {
          return value;
      }
  
      /**
       * Get value as two bytes in big endian byte order.
       * @param value the Java int to convert to bytes
       * @return the converted int as a byte array in big endian byte order
       */
      public static byte[] getBytes(int value) {
          byte[] result = new byte[2];
          result[0] = (byte) (value & BYTE_MASK);
          result[1] = (byte) ((value & BYTE_1_MASK) >> BYTE_1_SHIFT);
          return result;
      }
  
      /**
       * Helper method to get the value as a java int from two bytes starting at given array offset
       * @param bytes the array of bytes
       * @param offset the offset to start
       * @return the corresponding java int value
       */
      public static int getValue(byte[] bytes, int offset) {
          int value = (bytes[offset + 1] << BYTE_1_SHIFT) & BYTE_1_MASK;
          value += (bytes[offset] & BYTE_MASK);
          return value;
      }
  
      /**
       * Helper method to get the value as a java int from a two-byte array
       * @param bytes the array of bytes
       * @return the corresponding java int value
       */
      public static int getValue(byte[] bytes) {
          return getValue(bytes, 0);
      }
  
      /**
       * Override to make two instances with same value equal.
       * @param o an object to compare
       * @return true if the objects are equal
       * @since 1.1
       */
      @Override
      public boolean equals(Object o) {
          if (o == null || !(o instanceof ZipShort)) {
              return false;
          }
          return value == ((ZipShort) o).getValue();
      }
  
      /**
       * Override to make two instances with same value equal.
       * @return the value stored in the ZipShort
       * @since 1.1
       */
      @Override
      public int hashCode() {
          return value;
      }
  
      @Override
      public Object clone() {
          try {
              return super.clone();
          } catch (CloneNotSupportedException cnfe) {
              // impossible
              throw new RuntimeException(cnfe);
          }
      }
  
      @Override
      public String toString() {
          return "ZipShort value: " + value;
      }
  }
  