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Field.javaAPI DocApache Lucene 2.2.014550Sat Jun 16 22:20:38 BST 2007org.apache.lucene.document

Field

public final class Field extends AbstractField implements Serializable, Fieldable
A field is a section of a Document. Each field has two parts, a name and a value. Values may be free text, provided as a String or as a Reader, or they may be atomic keywords, which are not further processed. Such keywords may be used to represent dates, urls, etc. Fields are optionally stored in the index, so that they may be returned with hits on the document.

Fields Summary
Constructors Summary
public Field(String name, TokenStream tokenStream, TermVector termVector)
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 null

    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);
  
public Field(String name, byte[] value, Store 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
store How value should be stored (compressed or not)
throws
IllegalArgumentException if store is Store.NO

    if (name == null)
      throw new IllegalArgumentException("name cannot be null");
    if (value == null)
      throw new IllegalArgumentException("value cannot be null");
    
    this.name = name.intern();
    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)
      throw new IllegalArgumentException("binary values can't be unstored");
    else
      throw new IllegalArgumentException("unknown store parameter " + store);
    
    this.isIndexed   = false;
    this.isTokenized = false;
    
    this.isBinary    = true;
    
    setStoreTermVector(TermVector.NO);
  
public Field(String name, String value, Store store, Index index)
Create a field by specifying its name, value and how it will 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 value 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 null
throws
IllegalArgumentException if the field is neither stored nor indexed

    this(name, value, store, index, TermVector.NO);
  
public Field(String name, String value, Store store, Index index, TermVector termVector)
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 value 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 null
throws
IllegalArgumentException in any of the following situations:
  • the field is neither stored nor indexed
  • the field is not indexed but termVector is TermVector.YES

    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.TOKENIZED) {
      this.isIndexed = true;
      this.isTokenized = true;
    } else if (index == Index.UN_TOKENIZED) {
      this.isIndexed = true;
      this.isTokenized = false;
    } else if (index == Index.NO_NORMS) {
      this.isIndexed = true;
      this.isTokenized = false;
      this.omitNorms = true;
    } else {
      throw new IllegalArgumentException("unknown index parameter " + index);
    }
    
    this.isBinary = false;

    setStoreTermVector(termVector);
  
public Field(String name, Reader reader)
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 null

    this(name, reader, TermVector.NO);
  
public Field(String name, Reader reader, TermVector termVector)
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 null

    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);
  
public Field(String name, TokenStream tokenStream)
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 null

    this(name, tokenStream, TermVector.NO);
  
Methods Summary
public byte[]binaryValue()
The value of the field in Binary, or null. If null, the Reader value, String value, or TokenStream value is used. Exactly one of stringValue(), readerValue(), binaryValue(), and tokenStreamValue() must be set.

 return fieldsData instanceof byte[] ? (byte[])fieldsData : null; 
public java.io.ReaderreaderValue()
The value of the field as a Reader, or null. If null, the String value, binary value, or TokenStream value is used. Exactly one of stringValue(), readerValue(), binaryValue(), and tokenStreamValue() must be set.

 return fieldsData instanceof Reader ? (Reader)fieldsData : null; 
public java.lang.StringstringValue()
The value of the field as a String, or null. If null, the Reader value, binary value, or TokenStream value is used. Exactly one of stringValue(), readerValue(), binaryValue(), and tokenStreamValue() must be set.

  
  
  
                                       
        return fieldsData instanceof String ? (String)fieldsData : null; 
public org.apache.lucene.analysis.TokenStreamtokenStreamValue()
The value of the field as a TokesStream, or null. If null, the Reader value, String value, or binary value is used. Exactly one of stringValue(), readerValue(), binaryValue(), and tokenStreamValue() must be set.

 return fieldsData instanceof TokenStream ? (TokenStream)fieldsData : null;