org.apache.lucene.document
Class Field
public final
class
Field
extends Object
implements 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.
Constructor Summary |
| Field(String name, String string, boolean store, boolean index, boolean token) Create a field by specifying all parameters except for storeTermVector ,
which is set to false . |
| Field(String name, String string, boolean store, boolean index, boolean token, boolean storeTermVector)
|
Method Summary |
float | getBoost() Returns the boost factor for hits on any field of this document.
|
boolean | isIndexed() True iff the value of the field is to be indexed, so that it may be
searched on. |
boolean | isStored() True iff the value of the field is to be stored in the index for return
with search hits. |
boolean | isTermVectorStored() True iff the term or terms used to index this field are stored as a term
vector, available from {@link IndexReader#getTermFreqVector(int,String)}.
|
boolean | isTokenized() True iff the value of the field should be tokenized as text prior to
indexing. |
static Field | Keyword(String name, String value) Constructs a String-valued Field that is not tokenized, but is indexed
and stored. |
static Field | Keyword(String name, Date value) Constructs a Date-valued Field that is not tokenized and is indexed,
and stored in the index, for return with hits. |
String | name() The name of the field (e.g., "date", "subject", "title", or "body")
as an interned string. |
Reader | readerValue() The value of the field as a Reader, or null. |
void | setBoost(float boost) Sets the boost factor hits on this field. |
String | stringValue() The value of the field as a String, or null. |
String | toString() Prints a Field for human consumption. |
static Field | Text(String name, String value) Constructs a String-valued Field that is tokenized and indexed,
and is stored in the index, for return with hits. |
static Field | Text(String name, String value, boolean storeTermVector) Constructs a String-valued Field that is tokenized and indexed,
and is stored in the index, for return with hits. |
static Field | Text(String name, Reader value) Constructs a Reader-valued Field that is tokenized and indexed, but is
not stored in the index verbatim. |
static Field | Text(String name, Reader value, boolean storeTermVector) Constructs a Reader-valued Field that is tokenized and indexed, but is
not stored in the index verbatim. |
static Field | UnIndexed(String name, String value) Constructs a String-valued Field that is not tokenized nor indexed,
but is stored in the index, for return with hits. |
static Field | UnStored(String name, String value) Constructs a String-valued Field that is tokenized and indexed,
but that is not stored in the index. |
static Field | UnStored(String name, String value, boolean storeTermVector) Constructs a String-valued Field that is tokenized and indexed,
but that is not stored in the index. |
public Field(String name, String string, boolean store, boolean index, boolean token)
Create a field by specifying all parameters except for storeTermVector
,
which is set to false
.
public Field(String name, String string, boolean store, boolean index, boolean token, boolean storeTermVector)
Parameters: name The name of the field string The string to process store true if the field should store the string index true if the field should be indexed token true if the field should be tokenized storeTermVector true if we should store the Term Vector info
public float getBoost()
Returns the boost factor for hits on any field of this document.
The default value is 1.0.
Note: this value is not stored directly with the document in the index.
Documents returned from {@link IndexReader#document(int)} and {@link
Hits#doc(int)} may thus not have the same value present as when this field
was indexed.
See Also: Field
public final boolean isIndexed()
True iff the value of the field is to be indexed, so that it may be
searched on.
public final boolean isStored()
True iff the value of the field is to be stored in the index for return
with search hits. It is an error for this to be true if a field is
Reader-valued.
public final boolean isTermVectorStored()
True iff the term or terms used to index this field are stored as a term
vector, available from {@link IndexReader#getTermFreqVector(int,String)}.
These methods do not provide access to the original content of the field,
only to terms used to index it. If the original content must be
preserved, use the
stored
attribute instead.
See Also: IndexReader
public final boolean isTokenized()
True iff the value of the field should be tokenized as text prior to
indexing. Un-tokenized fields are indexed as a single word and may not be
Reader-valued.
public static final
Field Keyword(String name, String value)
Constructs a String-valued Field that is not tokenized, but is indexed
and stored. Useful for non-text fields, e.g. date or url.
public static final
Field Keyword(String name, Date value)
Constructs a Date-valued Field that is not tokenized and is indexed,
and stored in the index, for return with hits.
public String name()
The name of the field (e.g., "date", "subject", "title", or "body")
as an interned string.
public Reader readerValue()
The value of the field as a Reader, or null. If null, the String value
is used. Exactly one of stringValue() and readerValue() must be set.
public void setBoost(float boost)
Sets the boost factor hits on this field. This value will be
multiplied into the score of all hits on this this field of this
document.
The boost is multiplied by {@link Document#getBoost()} of the document
containing this field. If a document has multiple fields with the same
name, all such values are multiplied together. This product is then
multipled by the value {@link Similarity#lengthNorm(String,int)}, and
rounded by {@link Similarity#encodeNorm(float)} before it is stored in the
index. One should attempt to ensure that this product does not overflow
the range of that encoding.
See Also: Document Similarity Similarity
public String stringValue()
The value of the field as a String, or null. If null, the Reader value
is used. Exactly one of stringValue() and readerValue() must be set.
public final String toString()
Prints a Field for human consumption.
public static final
Field Text(String name, String value)
Constructs a String-valued Field that is tokenized and indexed,
and is stored in the index, for return with hits. Useful for short text
fields, like "title" or "subject". Term vector will not be stored for this field.
public static final
Field Text(String name, String value, boolean storeTermVector)
Constructs a String-valued Field that is tokenized and indexed,
and is stored in the index, for return with hits. Useful for short text
fields, like "title" or "subject".
public static final
Field Text(String name, Reader value)
Constructs a Reader-valued Field that is tokenized and indexed, but is
not stored in the index verbatim. Useful for longer text fields, like
"body". Term vector will not be stored for this field.
public static final
Field Text(String name, Reader value, boolean storeTermVector)
Constructs a Reader-valued Field that is tokenized and indexed, but is
not stored in the index verbatim. Useful for longer text fields, like
"body".
public static final
Field UnIndexed(String name, String value)
Constructs a String-valued Field that is not tokenized nor indexed,
but is stored in the index, for return with hits.
public static final
Field UnStored(String name, String value)
Constructs a String-valued Field that is tokenized and indexed,
but that is not stored in the index. Term vector will not be stored for this field.
public static final
Field UnStored(String name, String value, boolean storeTermVector)
Constructs a String-valued Field that is tokenized and indexed,
but that is not stored in the index.
Copyright © 2000-2007 Apache Software Foundation. All Rights Reserved.