pylucene 3.5.0-3

[pylucene.git] / lucene-java-3.5.0 / lucene / src / java / org / apache / lucene / analysis / PerFieldAnalyzerWrapper.java

diff --git a/lucene-java-3.5.0/lucene/src/java/org/apache/lucene/analysis/PerFieldAnalyzerWrapper.java b/lucene-java-3.5.0/lucene/src/java/org/apache/lucene/analysis/PerFieldAnalyzerWrapper.java
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+++ b/lucene-java-3.5.0/lucene/src/java/org/apache/lucene/analysis/PerFieldAnalyzerWrapper.java
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+package org.apache.lucene.analysis;
+
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import org.apache.lucene.document.Fieldable;
+
+import java.io.Reader;
+import java.io.IOException;
+import java.util.Map;
+import java.util.HashMap;
+
+/**
+ * This analyzer is used to facilitate scenarios where different
+ * fields require different analysis techniques.  Use the Map
+ * argument in {@link #PerFieldAnalyzerWrapper(Analyzer, java.util.Map)}
+ * to add non-default analyzers for fields.
+ * 
+ * <p>Example usage:
+ * 
+ * <pre>
+ *   Map analyzerPerField = new HashMap();
+ *   analyzerPerField.put("firstname", new KeywordAnalyzer());
+ *   analyzerPerField.put("lastname", new KeywordAnalyzer());
+ *
+ *   PerFieldAnalyzerWrapper aWrapper =
+ *      new PerFieldAnalyzerWrapper(new StandardAnalyzer(), analyzerPerField);
+ * </pre>
+ * 
+ * <p>In this example, StandardAnalyzer will be used for all fields except "firstname"
+ * and "lastname", for which KeywordAnalyzer will be used.
+ * 
+ * <p>A PerFieldAnalyzerWrapper can be used like any other analyzer, for both indexing
+ * and query parsing.
+ */
+public final class PerFieldAnalyzerWrapper extends Analyzer {
+  private final Analyzer defaultAnalyzer;
+  private final Map<String,Analyzer> analyzerMap = new HashMap<String,Analyzer>();
+
+
+  /**
+   * Constructs with default analyzer.
+   *
+   * @param defaultAnalyzer Any fields not specifically
+   * defined to use a different analyzer will use the one provided here.
+   */
+  public PerFieldAnalyzerWrapper(Analyzer defaultAnalyzer) {
+    this(defaultAnalyzer, null);
+  }
+  
+  /**
+   * Constructs with default analyzer and a map of analyzers to use for 
+   * specific fields.
+   *
+   * @param defaultAnalyzer Any fields not specifically
+   * defined to use a different analyzer will use the one provided here.
+   * @param fieldAnalyzers a Map (String field name to the Analyzer) to be 
+   * used for those fields 
+   */
+  public PerFieldAnalyzerWrapper(Analyzer defaultAnalyzer, 
+      Map<String,Analyzer> fieldAnalyzers) {
+    this.defaultAnalyzer = defaultAnalyzer;
+    if (fieldAnalyzers != null) {
+      analyzerMap.putAll(fieldAnalyzers);
+    }
+  }
+  
+
+  /**
+   * Defines an analyzer to use for the specified field.
+   *
+   * @param fieldName field name requiring a non-default analyzer
+   * @param analyzer non-default analyzer to use for field
+   * @deprecated Changing the Analyzer for a field after instantiation prevents
+   *             reusability.  Analyzers for fields should be set during construction.
+   */
+  @Deprecated
+  public void addAnalyzer(String fieldName, Analyzer analyzer) {
+    analyzerMap.put(fieldName, analyzer);
+  }
+
+  @Override
+  public TokenStream tokenStream(String fieldName, Reader reader) {
+    Analyzer analyzer = analyzerMap.get(fieldName);
+    if (analyzer == null) {
+      analyzer = defaultAnalyzer;
+    }
+
+    return analyzer.tokenStream(fieldName, reader);
+  }
+  
+  @Override
+  public TokenStream reusableTokenStream(String fieldName, Reader reader) throws IOException {
+    Analyzer analyzer = analyzerMap.get(fieldName);
+    if (analyzer == null)
+      analyzer = defaultAnalyzer;
+
+    return analyzer.reusableTokenStream(fieldName, reader);
+  }
+  
+  /** Return the positionIncrementGap from the analyzer assigned to fieldName */
+  @Override
+  public int getPositionIncrementGap(String fieldName) {
+    Analyzer analyzer = analyzerMap.get(fieldName);
+    if (analyzer == null)
+      analyzer = defaultAnalyzer;
+    return analyzer.getPositionIncrementGap(fieldName);
+  }
+
+  /** Return the offsetGap from the analyzer assigned to field */
+  @Override
+  public int getOffsetGap(Fieldable field) {
+    Analyzer analyzer = analyzerMap.get(field.name());
+    if (analyzer == null)
+      analyzer = defaultAnalyzer;
+    return analyzer.getOffsetGap(field);
+  }
+  
+  @Override
+  public String toString() {
+    return "PerFieldAnalyzerWrapper(" + analyzerMap + ", default=" + defaultAnalyzer + ")";
+  }
+}