pylucene 3.5.0-3

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

diff --git a/lucene-java-3.5.0/lucene/contrib/queryparser/src/java/org/apache/lucene/queryParser/standard/processors/AllowLeadingWildcardProcessor.java b/lucene-java-3.5.0/lucene/contrib/queryparser/src/java/org/apache/lucene/queryParser/standard/processors/AllowLeadingWildcardProcessor.java
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+++ b/lucene-java-3.5.0/lucene/contrib/queryparser/src/java/org/apache/lucene/queryParser/standard/processors/AllowLeadingWildcardProcessor.java
@@ -0,0 +1,105 @@
+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.messages.MessageImpl;
+import org.apache.lucene.queryParser.core.QueryNodeException;
+import org.apache.lucene.queryParser.core.config.QueryConfigHandler;
+import org.apache.lucene.queryParser.core.messages.QueryParserMessages;
+import org.apache.lucene.queryParser.core.nodes.QueryNode;
+import org.apache.lucene.queryParser.core.processors.QueryNodeProcessorImpl;
+import org.apache.lucene.queryParser.core.util.UnescapedCharSequence;
+import org.apache.lucene.queryParser.standard.config.StandardQueryConfigHandler.ConfigurationKeys;
+import org.apache.lucene.queryParser.standard.nodes.WildcardQueryNode;
+import org.apache.lucene.queryParser.standard.parser.EscapeQuerySyntaxImpl;
+
+/**
+ * This processor verifies if
+ * {@link ConfigurationKeys#ALLOW_LEADING_WILDCARD} is defined in the
+ * {@link QueryConfigHandler}. If it is and leading wildcard is not allowed, it
+ * looks for every {@link WildcardQueryNode} contained in the query node tree
+ * and throws an exception if any of them has a leading wildcard ('*' or '?'). <br/>
+ * 
+ * @see ConfigurationKeys#ALLOW_LEADING_WILDCARD
+ */
+public class AllowLeadingWildcardProcessor extends QueryNodeProcessorImpl {
+
+  public AllowLeadingWildcardProcessor() {
+    // empty constructor
+  }
+
+  @Override
+  public QueryNode process(QueryNode queryTree) throws QueryNodeException {
+    Boolean allowsLeadingWildcard = getQueryConfigHandler().get(ConfigurationKeys.ALLOW_LEADING_WILDCARD);
+
+    if (allowsLeadingWildcard != null) {
+
+      if (!allowsLeadingWildcard) {
+        return super.process(queryTree);
+      }
+
+    }
+
+    return queryTree;
+  }
+
+  @Override
+  protected QueryNode postProcessNode(QueryNode node) throws QueryNodeException {
+
+    if (node instanceof WildcardQueryNode) {
+      WildcardQueryNode wildcardNode = (WildcardQueryNode) node;
+
+      if (wildcardNode.getText().length() > 0) {
+        
+        // Validate if the wildcard was escaped
+        if (UnescapedCharSequence.wasEscaped(wildcardNode.getText(), 0))
+          return node;
+        
+        switch (wildcardNode.getText().charAt(0)) {    
+          case '*':
+          case '?':
+            throw new QueryNodeException(new MessageImpl(
+                QueryParserMessages.LEADING_WILDCARD_NOT_ALLOWED, node
+                    .toQueryString(new EscapeQuerySyntaxImpl())));    
+        }
+      }
+
+    }
+
+    return node;
+
+  }
+
+  @Override
+  protected QueryNode preProcessNode(QueryNode node) throws QueryNodeException {
+
+    return node;
+
+  }
+
+  @Override
+  protected List<QueryNode> setChildrenOrder(List<QueryNode> children)
+      throws QueryNodeException {
+
+    return children;
+
+  }
+
+}