OffsetAttributeImpl.java

package com.antbrains.wordseg.luceneanalyzer;

/**
 * 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.
 */

/**
 * The start and end character offset of a Token.
 */
public class OffsetAttributeImpl extends AttributeImpl implements OffsetAttribute, Cloneable {
  private int startOffset;
  private int endOffset;

  /**
   * Returns this Token's starting offset, the position of the first character corresponding to this
   * token in the source text.
   * 
   * Note that the difference between endOffset() and startOffset() may not be equal to
   * termText.length(), as the term text may have been altered by a stemmer or some other filter.
   */
  public int startOffset() {
    return startOffset;
  }

  /**
   * Set the starting and ending offset.
   * 
   * @see #startOffset() and #endOffset()
   */
  public void setOffset(int startOffset, int endOffset) {
    this.startOffset = startOffset;
    this.endOffset = endOffset;
  }

  /**
   * Returns this Token's ending offset, one greater than the position of the last character
   * corresponding to this token in the source text. The length of the token in the source text is
   * (endOffset - startOffset).
   */
  public int endOffset() {
    return endOffset;
  }

  @Override
  public void clear() {
    startOffset = 0;
    endOffset = 0;
  }

  @Override
  public boolean equals(Object other) {
    if (other == this) {
      return true;
    }

    if (other instanceof OffsetAttributeImpl) {
      OffsetAttributeImpl o = (OffsetAttributeImpl) other;
      return o.startOffset == startOffset && o.endOffset == endOffset;
    }

    return false;
  }

  @Override
  public int hashCode() {
    int code = startOffset;
    code = code * 31 + endOffset;
    return code;
  }

  @Override
  public void copyTo(AttributeImpl target) {
    OffsetAttribute t = (OffsetAttribute) target;
    t.setOffset(startOffset, endOffset);
  }
}