1 package org.apache.lucene.document;
2
3 /**
4 * Copyright 2004 The Apache Software Foundation
5 *
6 * Licensed under the Apache License, Version 2.0 (the "License");
7 * you may not use this file except in compliance with the License.
8 * You may obtain a copy of the License at
9 *
10 * http://www.apache.org/licenses/LICENSE-2.0
11 *
12 * Unless required by applicable law or agreed to in writing, software
13 * distributed under the License is distributed on an "AS IS" BASIS,
14 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15 * See the License for the specific language governing permissions and
16 * limitations under the License.
17 */
18
19 import java.io.Reader;
20 import java.io.Serializable;
21
22 import org.apache.lucene.analysis.TokenStream;
23
24 /**
25 * Synonymous with {@link Field}.
26 *
27 **/
28 public interface Fieldable extends Serializable {
29 /** Sets the boost factor hits on this field. This value will be
30 * multiplied into the score of all hits on this this field of this
31 * document.
32 *
33 * <p>The boost is multiplied by {@link org.apache.lucene.document.Document#getBoost()} of the document
34 * containing this field. If a document has multiple fields with the same
35 * name, all such values are multiplied together. This product is then
36 * multipled by the value {@link org.apache.lucene.search.Similarity#lengthNorm(String,int)}, and
37 * rounded by {@link org.apache.lucene.search.Similarity#encodeNorm(float)} before it is stored in the
38 * index. One should attempt to ensure that this product does not overflow
39 * the range of that encoding.
40 *
41 * @see org.apache.lucene.document.Document#setBoost(float)
42 * @see org.apache.lucene.search.Similarity#lengthNorm(String, int)
43 * @see org.apache.lucene.search.Similarity#encodeNorm(float)
44 */
45 void setBoost(float boost);
46
47 /** Returns the boost factor for hits for this field.
48 *
49 * <p>The default value is 1.0.
50 *
51 * <p>Note: this value is not stored directly with the document in the index.
52 * Documents returned from {@link org.apache.lucene.index.IndexReader#document(int)} and
53 * {@link org.apache.lucene.search.Hits#doc(int)} may thus not have the same value present as when
54 * this field was indexed.
55 *
56 * @see #setBoost(float)
57 */
58 float getBoost();
59
60 /** Returns the name of the field as an interned string.
61 * For example "date", "title", "body", ...
62 */
63 String name();
64
65 /** The value of the field as a String, or null. If null, the Reader value,
66 * binary value, or TokenStream value is used. Exactly one of stringValue(),
67 * readerValue(), binaryValue(), and tokenStreamValue() must be set. */
68 public String stringValue();
69
70 /** The value of the field as a Reader, or null. If null, the String value,
71 * binary value, or TokenStream value is used. Exactly one of stringValue(),
72 * readerValue(), binaryValue(), and tokenStreamValue() must be set. */
73 public Reader readerValue();
74
75 /** The value of the field in Binary, or null. If null, the Reader value,
76 * String value, or TokenStream value is used. Exactly one of stringValue(),
77 * readerValue(), binaryValue(), and tokenStreamValue() must be set. */
78 public byte[] binaryValue();
79
80 /** The value of the field as a TokenStream, or null. If null, the Reader value,
81 * String value, or binary value is used. Exactly one of stringValue(),
82 * readerValue(), binaryValue(), and tokenStreamValue() must be set. */
83 public TokenStream tokenStreamValue();
84
85 /** True iff the value of the field is to be stored in the index for return
86 with search hits. It is an error for this to be true if a field is
87 Reader-valued. */
88 boolean isStored();
89
90 /** True iff the value of the field is to be indexed, so that it may be
91 searched on. */
92 boolean isIndexed();
93
94 /** True iff the value of the field should be tokenized as text prior to
95 indexing. Un-tokenized fields are indexed as a single word and may not be
96 Reader-valued. */
97 boolean isTokenized();
98
99 /** True if the value of the field is stored and compressed within the index */
100 boolean isCompressed();
101
102 /** True iff the term or terms used to index this field are stored as a term
103 * vector, available from {@link org.apache.lucene.index.IndexReader#getTermFreqVector(int,String)}.
104 * These methods do not provide access to the original content of the field,
105 * only to terms used to index it. If the original content must be
106 * preserved, use the <code>stored</code> attribute instead.
107 *
108 * @see org.apache.lucene.index.IndexReader#getTermFreqVector(int, String)
109 */
110 boolean isTermVectorStored();
111
112 /**
113 * True iff terms are stored as term vector together with their offsets
114 * (start and end positon in source text).
115 */
116 boolean isStoreOffsetWithTermVector();
117
118 /**
119 * True iff terms are stored as term vector together with their token positions.
120 */
121 boolean isStorePositionWithTermVector();
122
123 /** True iff the value of the filed is stored as binary */
124 boolean isBinary();
125
126 /** True if norms are omitted for this indexed field */
127 boolean getOmitNorms();
128
129 /** Expert:
130 *
131 * If set, omit normalization factors associated with this indexed field.
132 * This effectively disables indexing boosts and length normalization for this field.
133 */
134 void setOmitNorms(boolean omitNorms);
135
136 /**
137 * Indicates whether a Field is Lazy or not. The semantics of Lazy loading are such that if a Field is lazily loaded, retrieving
138 * it's values via {@link #stringValue()} or {@link #binaryValue()} is only valid as long as the {@link org.apache.lucene.index.IndexReader} that
139 * retrieved the {@link Document} is still open.
140 *
141 * @return true if this field can be loaded lazily
142 */
143 boolean isLazy();
144 }
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