Class Document
- java.lang.Object
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- org.apache.lucene.document.Document
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- All Implemented Interfaces:
Serializable
public final class Document extends Object implements Serializable
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 bestored
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. withScoreDoc.doc
,Searcher.doc(int)
orIndexReader.document(int)
.- See Also:
- Serialized Form
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Constructor Summary
Constructors Constructor Description Document()
Constructs a new document with no fields.
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Method Summary
All Methods Instance Methods Concrete Methods Deprecated Methods Modifier and Type Method Description void
add(Fieldable 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.byte[]
getBinaryValue(String name)
Returns an array of bytes for the first (or only) field that has the name specified as the method parameter.byte[][]
getBinaryValues(String name)
Returns an array of byte arrays for of the fields that have the name specified as the method parameter.float
getBoost()
Returns, at indexing time, the boost factor as set bysetBoost(float)
.Field
getField(String name)
Deprecated.usegetFieldable(java.lang.String)
instead and cast depending on data type.Fieldable
getFieldable(String name)
Returns a field with the given name if any exist in this document, or null.Fieldable[]
getFieldables(String name)
Returns an array ofFieldable
s with the given name.List<Fieldable>
getFields()
Returns a List of all the fields in a document.Field[]
getFields(String name)
Deprecated.usegetFieldable(java.lang.String)
instead and cast depending on data type.String[]
getValues(String name)
Returns an array of values of the field specified as the method parameter.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.void
setBoost(float boost)
Sets a boost factor for hits on any field of this document.String
toString()
Prints the fields of a document for human consumption.
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Method Detail
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setBoost
public void setBoost(float boost)
Sets a boost factor for hits on any field of this document. This value will be multiplied into the score of all hits on this document.The default value is 1.0.
Values are multiplied into the value of
Fieldable.getBoost()
of each field in this document. Thus, this method in effect sets a default boost for the fields of this document.- See Also:
Fieldable.setBoost(float)
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getBoost
public float getBoost()
Returns, at indexing time, the boost factor as set bysetBoost(float)
.Note that once a document is indexed this value is no longer available from the index. At search time, for retrieved documents, this method always returns 1. This however does not mean that the boost value set at indexing time was ignored - it was just combined with other indexing time factors and stored elsewhere, for better indexing and search performance. (For more information see the "norm(t,d)" part of the scoring formula in
Similarity
.)- See Also:
setBoost(float)
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add
public final void add(Fieldable 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.
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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.
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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.
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getField
@Deprecated public final Field getField(String name)
Deprecated.usegetFieldable(java.lang.String)
instead and cast depending on data type.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. Do not use this method with lazy loaded fields orNumericField
.- Throws:
ClassCastException
- if you try to retrieve a numerical or lazy loaded field.
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getFieldable
public Fieldable getFieldable(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.
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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. ForNumericField
it returns the string value of the number. If you want the actualNumericField
instance back, usegetFieldable(java.lang.String)
.
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getFields
public final List<Fieldable> 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.Searcher.doc(int)
orIndexReader.document(int)
.
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getFields
@Deprecated public final Field[] getFields(String name)
Deprecated.usegetFieldable(java.lang.String)
instead and cast depending on data type.Returns an array ofField
s with the given name. This method returns an empty array when there are no matching fields. It never returns null. Do not use this method with lazy loaded fields orNumericField
.- Parameters:
name
- the name of the field- Returns:
- a
Field[]
array - Throws:
ClassCastException
- if you try to retrieve a numerical or lazy loaded field.
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getFieldables
public Fieldable[] getFieldables(String name)
Returns an array ofFieldable
s 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
Fieldable[]
array
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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. ForNumericField
s it returns the string value of the number. If you want the actualNumericField
instances back, usegetFieldables(java.lang.String)
.- Parameters:
name
- the name of the field- Returns:
- a
String[]
of field values
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getBinaryValues
public final byte[][] 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
byte[][]
of binary field values
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getBinaryValue
public final byte[] 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 returnnull
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
byte[]
containing the binary field value ornull
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