pylucene 3.5.0-3

[pylucene.git] / lucene-java-3.5.0 / lucene / contrib / queryparser / src / java / org / apache / lucene / queryParser / standard / processors / WildcardQueryNodeProcessor.java

diff --git a/lucene-java-3.5.0/lucene/contrib/queryparser/src/java/org/apache/lucene/queryParser/standard/processors/WildcardQueryNodeProcessor.java b/lucene-java-3.5.0/lucene/contrib/queryparser/src/java/org/apache/lucene/queryParser/standard/processors/WildcardQueryNodeProcessor.java
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+++ b/lucene-java-3.5.0/lucene/contrib/queryparser/src/java/org/apache/lucene/queryParser/standard/processors/WildcardQueryNodeProcessor.java
@@ -0,0 +1,139 @@
+package org.apache.lucene.queryParser.standard.processors;
+
+/**
+ * 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 java.util.List;
+
+import org.apache.lucene.queryParser.core.QueryNodeException;
+import org.apache.lucene.queryParser.core.nodes.FieldQueryNode;
+import org.apache.lucene.queryParser.core.nodes.FuzzyQueryNode;
+import org.apache.lucene.queryParser.core.nodes.ParametricQueryNode;
+import org.apache.lucene.queryParser.core.nodes.QueryNode;
+import org.apache.lucene.queryParser.core.nodes.QuotedFieldQueryNode;
+import org.apache.lucene.queryParser.core.processors.QueryNodeProcessorImpl;
+import org.apache.lucene.queryParser.core.util.UnescapedCharSequence;
+import org.apache.lucene.queryParser.standard.nodes.PrefixWildcardQueryNode;
+import org.apache.lucene.queryParser.standard.nodes.WildcardQueryNode;
+import org.apache.lucene.queryParser.standard.parser.StandardSyntaxParser;
+import org.apache.lucene.search.PrefixQuery;
+
+/**
+ * The {@link StandardSyntaxParser} creates {@link PrefixWildcardQueryNode} nodes which
+ * have values containing the prefixed wildcard. However, Lucene
+ * {@link PrefixQuery} cannot contain the prefixed wildcard. So, this processor
+ * basically removed the prefixed wildcard from the
+ * {@link PrefixWildcardQueryNode} value. <br/>
+ * 
+ * @see PrefixQuery
+ * @see PrefixWildcardQueryNode
+ */
+public class WildcardQueryNodeProcessor extends QueryNodeProcessorImpl {
+
+  public WildcardQueryNodeProcessor() {
+    // empty constructor
+  }
+
+  @Override
+  protected QueryNode postProcessNode(QueryNode node) throws QueryNodeException {
+
+    // the old Lucene Parser ignores FuzzyQueryNode that are also PrefixWildcardQueryNode or WildcardQueryNode
+    // we do the same here, also ignore empty terms
+    if (node instanceof FieldQueryNode || node instanceof FuzzyQueryNode) {      
+      FieldQueryNode fqn = (FieldQueryNode) node;      
+      CharSequence text = fqn.getText(); 
+      
+      // do not process wildcards for ParametricQueryNode and 
+      // QuotedFieldQueryNode to reproduce the old parser behavior
+      if (fqn instanceof ParametricQueryNode 
+          || fqn instanceof QuotedFieldQueryNode 
+          || text.length() <= 0){
+        // Ignore empty terms
+        return node;
+      }
+      
+      // Code below simulates the old lucene parser behavior for wildcards
+      
+      if (isPrefixWildcard(text)) {        
+        PrefixWildcardQueryNode prefixWildcardQN = new PrefixWildcardQueryNode(fqn);
+        return prefixWildcardQN;
+        
+      } else if (isWildcard(text)){
+        WildcardQueryNode wildcardQN = new WildcardQueryNode(fqn);
+        return wildcardQN;
+      }
+             
+    }
+
+    return node;
+
+  }
+
+  private boolean isWildcard(CharSequence text) {
+    if (text ==null || text.length() <= 0) return false;
+    
+    // If a un-escaped '*' or '?' if found return true
+    // start at the end since it's more common to put wildcards at the end
+    for(int i=text.length()-1; i>=0; i--){
+      if ((text.charAt(i) == '*' || text.charAt(i) == '?') && !UnescapedCharSequence.wasEscaped(text, i)){
+        return true;
+      }
+    }
+    
+    return false;
+  }
+
+  private boolean isPrefixWildcard(CharSequence text) {
+    if (text == null || text.length() <= 0 || !isWildcard(text)) return false;
+    
+    // Validate last character is a '*' and was not escaped
+    // If single '*' is is a wildcard not prefix to simulate old queryparser
+    if (text.charAt(text.length()-1) != '*') return false;
+    if (UnescapedCharSequence.wasEscaped(text, text.length()-1)) return false;
+    if (text.length() == 1) return false;
+      
+    // Only make a prefix if there is only one single star at the end and no '?' or '*' characters
+    // If single wildcard return false to mimic old queryparser
+    for(int i=0; i<text.length(); i++){
+      if (text.charAt(i) == '?') return false;
+      if (text.charAt(i) == '*' && !UnescapedCharSequence.wasEscaped(text, i)){        
+        if (i == text.length()-1) 
+          return true;
+        else 
+          return false;
+      }
+    }
+    
+    return false;
+  }
+
+  @Override
+  protected QueryNode preProcessNode(QueryNode node) throws QueryNodeException {
+
+    return node;
+
+  }
+
+  @Override
+  protected List<QueryNode> setChildrenOrder(List<QueryNode> children)
+      throws QueryNodeException {
+
+    return children;
+
+  }
+
+}