Class Field

  • All Implemented Interfaces:
    Serializable, Fieldable

    public final class Field
    extends AbstractField
    implements Fieldable, Serializable
    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.
    See Also:
    Serialized Form
    • Constructor Detail

      • Field

        public Field​(String name,
                     String value,
                     Field.Store store,
                     Field.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.
        Parameters:
        name - The name of the field
        value - The string to process
        store - Whether value should be stored in the index
        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
        IllegalArgumentException - if the field is neither stored nor indexed
      • Field

        public Field​(String name,
                     String value,
                     Field.Store store,
                     Field.Index index,
                     Field.TermVector termVector)
        Create a field by specifying its name, value and how it will be saved in the index.
        Parameters:
        name - The name of the field
        value - The string to process
        store - Whether value should be stored in the index
        index - Whether the field should be indexed, and if so, if it should be tokenized before indexing
        termVector - Whether term vector should be stored
        Throws:
        NullPointerException - if name or value is null
        IllegalArgumentException - in any of the following situations:
        • the field is neither stored nor indexed
        • the field is not indexed but termVector is TermVector.YES
      • Field

        public Field​(String name,
                     boolean internName,
                     String value,
                     Field.Store store,
                     Field.Index index,
                     Field.TermVector termVector)
        Create a field by specifying its name, value and how it will be saved in the index.
        Parameters:
        name - The name of the field
        internName - Whether to .intern() name or not
        value - The string to process
        store - Whether value should be stored in the index
        index - Whether the field should be indexed, and if so, if it should be tokenized before indexing
        termVector - Whether term vector should be stored
        Throws:
        NullPointerException - if name or value is null
        IllegalArgumentException - in any of the following situations:
        • the field is neither stored nor indexed
        • the field is not indexed but termVector is TermVector.YES
      • Field

        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 IndexWriter.addDocument(Document) has been called.
        Parameters:
        name - The name of the field
        reader - The reader with the content
        Throws:
        NullPointerException - if name or reader is null
      • Field

        public Field​(String name,
                     Reader reader,
                     Field.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 IndexWriter.addDocument(Document) has been called.
        Parameters:
        name - The name of the field
        reader - The reader with the content
        termVector - Whether term vector should be stored
        Throws:
        NullPointerException - if name or reader is null
      • Field

        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 IndexWriter.addDocument(Document) has been called.
        Parameters:
        name - The name of the field
        tokenStream - The TokenStream with the content
        Throws:
        NullPointerException - if name or tokenStream is null
      • Field

        public Field​(String name,
                     TokenStream tokenStream,
                     Field.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 IndexWriter.addDocument(Document) has been called.
        Parameters:
        name - The name of the field
        tokenStream - The TokenStream with the content
        termVector - Whether term vector should be stored
        Throws:
        NullPointerException - if name or tokenStream is null
      • Field

        @Deprecated
        public Field​(String name,
                     byte[] value,
                     Field.Store store)
        Deprecated.
        Create a stored field with binary value. Optionally the value may be compressed.
        Parameters:
        name - The name of the field
        value - The binary value
        store - Must be Store.YES
        Throws:
        IllegalArgumentException - if store is Store.NO
      • Field

        public Field​(String name,
                     byte[] value)
        Create a stored field with binary value. Optionally the value may be compressed.
        Parameters:
        name - The name of the field
        value - The binary value
      • Field

        @Deprecated
        public Field​(String name,
                     byte[] value,
                     int offset,
                     int length,
                     Field.Store store)
        Deprecated.
        Create a stored field with binary value. Optionally the value may be compressed.
        Parameters:
        name - The name of the field
        value - The binary value
        offset - Starting offset in value where this Field's bytes are
        length - Number of bytes to use for this Field, starting at offset
        store - How value should be stored (compressed or not)
        Throws:
        IllegalArgumentException - if store is Store.NO
      • Field

        public Field​(String name,
                     byte[] value,
                     int offset,
                     int length)
        Create a stored field with binary value. Optionally the value may be compressed.
        Parameters:
        name - The name of the field
        value - The binary value
        offset - Starting offset in value where this Field's bytes are
        length - Number of bytes to use for this Field, starting at offset
    • Method Detail

      • stringValue

        public String stringValue()
        The value of the field as a String, or null. If null, the Reader value or binary value is used. Exactly one of stringValue(), readerValue(), and getBinaryValue() must be set.
        Specified by:
        stringValue in interface Fieldable
      • readerValue

        public Reader readerValue()
        The value of the field as a Reader, or null. If null, the String value or binary value is used. Exactly one of stringValue(), readerValue(), and getBinaryValue() must be set.
        Specified by:
        readerValue in interface Fieldable
        See Also:
        Fieldable.stringValue()
      • tokenStreamValue

        public TokenStream tokenStreamValue()
        The TokesStream for this field to be used when indexing, or null. If null, the Reader value or String value is analyzed to produce the indexed tokens.
        Specified by:
        tokenStreamValue in interface Fieldable
        See Also:
        Fieldable.stringValue()
      • setValue

        public void setValue​(String value)

        Expert: change the value of this field. This can be used during indexing to re-use a single Field instance to improve indexing speed by avoiding GC cost of new'ing and reclaiming Field instances. Typically a single Document instance is re-used as well. This helps most on small documents.

        Each Field instance should only be used once within a single Document instance. See ImproveIndexingSpeed for details.

      • setValue

        public void setValue​(Reader value)
        Expert: change the value of this field. See setValue(String).
      • setValue

        public void setValue​(byte[] value)
        Expert: change the value of this field. See setValue(String).
      • setValue

        public void setValue​(byte[] value,
                             int offset,
                             int length)
        Expert: change the value of this field. See setValue(String).
      • setTokenStream

        public void setTokenStream​(TokenStream tokenStream)
        Expert: sets the token stream to be used for indexing and causes isIndexed() and isTokenized() to return true. May be combined with stored values from stringValue() or getBinaryValue()