org.apache.lucene.document

Class Document

java.lang.Object

org.apache.lucene.document.Document

All Implemented Interfaces:

Iterable<IndexableField>

public final class Document
extends Object
implements Iterable<IndexableField>

Documents are the unit of indexing and search. A Document is a set of fields. Each field has a name and a textual value. A field may be stored with the document, in which case it is returned with search hits on the document. Thus each document should typically contain one or more stored fields which uniquely identify it.

Note that fields which are not stored are not available in documents retrieved from the index, e.g. with ScoreDoc.doc or IndexReader.document(int).

Constructor Summary

Constructors

Constructor and Description
Document() Constructs a new document with no fields.

Method Summary

Methods

Modifier and Type	Method and Description
void	add(IndexableField field) Adds a field to a document.
String	get(String name) Returns the string value of the field with the given name if any exist in this document, or null.
BytesRef	getBinaryValue(String name) Returns an array of bytes for the first (or only) field that has the name specified as the method parameter.
BytesRef[]	getBinaryValues(String name) Returns an array of byte arrays for of the fields that have the name specified as the method parameter.
IndexableField	getField(String name) Returns a field with the given name if any exist in this document, or null.
List<IndexableField>	getFields() Returns a List of all the fields in a document.
IndexableField[]	getFields(String name) Returns an array of IndexableFields with the given name.
String[]	getValues(String name) Returns an array of values of the field specified as the method parameter.
Iterator<IndexableField>	iterator()
void	removeField(String name) Removes field with the specified name from the document.
void	removeFields(String name) Removes all fields with the given name from the document.
String	toString() Prints the fields of a document for human consumption.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

Document

public Document()

Constructs a new document with no fields.

Method Detail

iterator

public Iterator<IndexableField> iterator()

Specified by:

iterator in interface Iterable<IndexableField>

add

public final void add(IndexableField field)

Adds a field to a document. Several fields may be added with the same name. In this case, if the fields are indexed, their text is treated as though appended for the purposes of search.

Note that add like the removeField(s) methods only makes sense prior to adding a document to an index. These methods cannot be used to change the content of an existing index! In order to achieve this, a document has to be deleted from an index and a new changed version of that document has to be added.

removeField

public final void removeField(String name)

Removes field with the specified name from the document. If multiple fields exist with this name, this method removes the first field that has been added. If there is no field with the specified name, the document remains unchanged.

Note that the removeField(s) methods like the add method only make sense prior to adding a document to an index. These methods cannot be used to change the content of an existing index! In order to achieve this, a document has to be deleted from an index and a new changed version of that document has to be added.

removeFields

public final void removeFields(String name)

Removes all fields with the given name from the document. If there is no field with the specified name, the document remains unchanged.

Note that the removeField(s) methods like the add method only make sense prior to adding a document to an index. These methods cannot be used to change the content of an existing index! In order to achieve this, a document has to be deleted from an index and a new changed version of that document has to be added.

getBinaryValues

public final BytesRef[] getBinaryValues(String name)

Returns an array of byte arrays for of the fields that have the name specified as the method parameter. This method returns an empty array when there are no matching fields. It never returns null.

Parameters:

name - the name of the field

Returns:

a BytesRef[] of binary field values

getBinaryValue

public final BytesRef getBinaryValue(String name)

Returns an array of bytes for the first (or only) field that has the name specified as the method parameter. This method will return null if no binary fields with the specified name are available. There may be non-binary fields with the same name.

Parameters:

name - the name of the field.

Returns:

a BytesRef containing the binary field value or null

getField

public final IndexableField getField(String name)

Returns a field with the given name if any exist in this document, or null. If multiple fields exists with this name, this method returns the first value added.

getFields

public IndexableField[] getFields(String name)

Returns an array of IndexableFields with the given name. This method returns an empty array when there are no matching fields. It never returns null.

Parameters:

name - the name of the field

Returns:

a IndexableField[] array

getFields

public final List<IndexableField> getFields()

Returns a List of all the fields in a document.

Note that fields which are not stored are not available in documents retrieved from the index, e.g. IndexSearcher.doc(int) or IndexReader.document(int).

getValues

public final String[] getValues(String name)

Returns an array of values of the field specified as the method parameter. This method returns an empty array when there are no matching fields. It never returns null. For IntField, LongField, FloatField and DoubleField it returns the string value of the number. If you want the actual numeric field instances back, use getFields(java.lang.String).

Parameters:

name - the name of the field

Returns:

a String[] of field values

get

public final String get(String name)

Returns the string value of the field with the given name if any exist in this document, or null. If multiple fields exist with this name, this method returns the first value added. If only binary fields with this name exist, returns null. For IntField, LongField, FloatField and DoubleField it returns the string value of the number. If you want the actual numeric field instance back, use getField(java.lang.String).

toString

public final String toString()

Prints the fields of a document for human consumption.

Overrides:

toString in class Object