field.java

lucene-2.4.0 是一个全文收索的工具包

   * be saved in the index. Term vectors will not be stored in the index.
   * 
   * @param name The name of the field
   * @param value The string to process
   * @param store Whether <code>value</code> should be stored in the index
   * @param index Whether the field should be indexed, and if so, if it should
   *  be tokenized before indexing 
   * @throws NullPointerException if name or value is <code>null</code>
   * @throws IllegalArgumentException if the field is neither stored nor indexed 
   */
  public Field(String name, String value, Store store, Index index) {
    this(name, value, store, index, TermVector.NO);
  }
  
  /**
   * Create a field by specifying its name, value and how it will
   * be saved in the index.
   * 
   * @param name The name of the field
   * @param value The string to process
   * @param store Whether <code>value</code> should be stored in the index
   * @param index Whether the field should be indexed, and if so, if it should
   *  be tokenized before indexing 
   * @param termVector Whether term vector should be stored
   * @throws NullPointerException if name or value is <code>null</code>
   * @throws IllegalArgumentException in any of the following situations:
   * <ul> 
   *  <li>the field is neither stored nor indexed</li> 
   *  <li>the field is not indexed but termVector is <code>TermVector.YES</code></li>
   * </ul> 
   */ 
  public Field(String name, String value, Store store, Index index, TermVector termVector) {
    if (name == null)
      throw new NullPointerException("name cannot be null");
    if (value == null)
      throw new NullPointerException("value cannot be null");
    if (name.length() == 0 && value.length() == 0)
      throw new IllegalArgumentException("name and value cannot both be empty");
    if (index == Index.NO && store == Store.NO)
      throw new IllegalArgumentException("it doesn't make sense to have a field that "
         + "is neither indexed nor stored");
    if (index == Index.NO && termVector != TermVector.NO)
      throw new IllegalArgumentException("cannot store term vector information "
         + "for a field that is not indexed");
          
    this.name = name.intern();        // field names are interned
    this.fieldsData = value;

    if (store == Store.YES){
      this.isStored = true;
      this.isCompressed = false;
    }
    else if (store == Store.COMPRESS) {
      this.isStored = true;
      this.isCompressed = true;
    }
    else if (store == Store.NO){
      this.isStored = false;
      this.isCompressed = false;
    }
    else
      throw new IllegalArgumentException("unknown store parameter " + store);
   
    if (index == Index.NO) {
      this.isIndexed = false;
      this.isTokenized = false;
    } else if (index == Index.ANALYZED) {
      this.isIndexed = true;
      this.isTokenized = true;
    } else if (index == Index.NOT_ANALYZED) {
      this.isIndexed = true;
      this.isTokenized = false;
    } else if (index == Index.NOT_ANALYZED_NO_NORMS) {
      this.isIndexed = true;
      this.isTokenized = false;
      this.omitNorms = true;
    } else if (index == Index.ANALYZED_NO_NORMS) {
      this.isIndexed = true;
      this.isTokenized = true;
      this.omitNorms = true;
    } else {
      throw new IllegalArgumentException("unknown index parameter " + index);
    }
    
    this.isBinary = false;

    setStoreTermVector(termVector);
  }

  /**
   * Create a tokenized and indexed field that is not stored. Term vectors will
   * not be stored.  The Reader is read only when the Document is added to the index,
   * i.e. you may not close the Reader until {@link IndexWriter#addDocument(Document)}
   * has been called.
   * 
   * @param name The name of the field
   * @param reader The reader with the content
   * @throws NullPointerException if name or reader is <code>null</code>
   */
  public Field(String name, Reader reader) {
    this(name, reader, TermVector.NO);
  }

  /**
   * Create a tokenized and indexed field that is not stored, optionally with 
   * storing term vectors.  The Reader is read only when the Document is added to the index,
   * i.e. you may not close the Reader until {@link IndexWriter#addDocument(Document)}
   * has been called.
   * 
   * @param name The name of the field
   * @param reader The reader with the content
   * @param termVector Whether term vector should be stored
   * @throws NullPointerException if name or reader is <code>null</code>
   */ 
  public Field(String name, Reader reader, TermVector termVector) {
    if (name == null)
      throw new NullPointerException("name cannot be null");
    if (reader == null)
      throw new NullPointerException("reader cannot be null");
    
    this.name = name.intern();        // field names are interned
    this.fieldsData = reader;
    
    this.isStored = false;
    this.isCompressed = false;
    
    this.isIndexed = true;
    this.isTokenized = true;
    
    this.isBinary = false;
    
    setStoreTermVector(termVector);
  }

  /**
   * Create a tokenized and indexed field that is not stored. Term vectors will
   * not be stored. This is useful for pre-analyzed fields.
   * The TokenStream is read only when the Document is added to the index,
   * i.e. you may not close the TokenStream until {@link IndexWriter#addDocument(Document)}
   * has been called.
   * 
   * @param name The name of the field
   * @param tokenStream The TokenStream with the content
   * @throws NullPointerException if name or tokenStream is <code>null</code>
   */ 
  public Field(String name, TokenStream tokenStream) {
    this(name, tokenStream, TermVector.NO);
  }
  
  /**
   * Create a tokenized and indexed field that is not stored, optionally with 
   * storing term vectors.  This is useful for pre-analyzed fields.
   * The TokenStream is read only when the Document is added to the index,
   * i.e. you may not close the TokenStream until {@link IndexWriter#addDocument(Document)}
   * has been called.
   * 
   * @param name The name of the field
   * @param tokenStream The TokenStream with the content
   * @param termVector Whether term vector should be stored
   * @throws NullPointerException if name or tokenStream is <code>null</code>
   */ 
  public Field(String name, TokenStream tokenStream, TermVector termVector) {
    if (name == null)
      throw new NullPointerException("name cannot be null");
    if (tokenStream == null)
      throw new NullPointerException("tokenStream cannot be null");
    
    this.name = name.intern();        // field names are interned
    this.fieldsData = tokenStream;
    
    this.isStored = false;
    this.isCompressed = false;
    
    this.isIndexed = true;
    this.isTokenized = true;
    
    this.isBinary = false;
    
    setStoreTermVector(termVector);
  }

  
  /**
   * Create a stored field with binary value. Optionally the value may be compressed.
   * 
   * @param name The name of the field
   * @param value The binary value
   * @param store How <code>value</code> should be stored (compressed or not)
   * @throws IllegalArgumentException if store is <code>Store.NO</code> 
   */
  public Field(String name, byte[] value, Store store) {
    this(name, value, 0, value.length, store);
  }

  /**
   * Create a stored field with binary value. Optionally the value may be compressed.
   * 
   * @param name The name of the field
   * @param value The binary value
   * @param offset Starting offset in value where this Field's bytes are
   * @param length Number of bytes to use for this Field, starting at offset
   * @param store How <code>value</code> should be stored (compressed or not)
   * @throws IllegalArgumentException if store is <code>Store.NO</code> 
   */
  public Field(String name, byte[] value, int offset, int length, Store store) {

    if (name == null)
      throw new IllegalArgumentException("name cannot be null");
    if (value == null)
      throw new IllegalArgumentException("value cannot be null");
    
    this.name = name.intern();
    fieldsData = value;
    
    if (store == Store.YES) {
      isStored = true;
      isCompressed = false;
    }
    else if (store == Store.COMPRESS) {
      isStored = true;
      isCompressed = true;
    }
    else if (store == Store.NO)
      throw new IllegalArgumentException("binary values can't be unstored");
    else
      throw new IllegalArgumentException("unknown store parameter " + store);
    
    isIndexed   = false;
    isTokenized = false;
    
    isBinary    = true;
    binaryLength = length;
    binaryOffset = offset;
    
    setStoreTermVector(TermVector.NO);
  }
}