svn commit: r1542596 - /mahout/trunk/integration/src/main/java/org/apache/mahout/text/LuceneIndexHelper.java

[sm...@apache.org]

Author: smarthi
Date: Sat Nov 16 21:56:39 2013
New Revision: 1542596

URL: http://svn.apache.org/r1542596
Log:
MAHOUT-1292:lucene2seq should validate the 'id' field

Added:
    mahout/trunk/integration/src/main/java/org/apache/mahout/text/LuceneIndexHelper.java

Added: mahout/trunk/integration/src/main/java/org/apache/mahout/text/LuceneIndexHelper.java
URL: http://svn.apache.org/viewvc/mahout/trunk/integration/src/main/java/org/apache/mahout/text/LuceneIndexHelper.java?rev=1542596&view=auto
==============================================================================
--- mahout/trunk/integration/src/main/java/org/apache/mahout/text/LuceneIndexHelper.java (added)
+++ mahout/trunk/integration/src/main/java/org/apache/mahout/text/LuceneIndexHelper.java Sat Nov 16 21:56:39 2013
@@ -0,0 +1,40 @@
+package org.apache.mahout.text;
+/*
+ * 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.search.CollectionStatistics;
+import org.apache.lucene.search.IndexSearcher;
+
+import java.io.IOException;
+
+/**
+ * Utility for checking if a field exist in a Lucene index.
+ */
+public class LuceneIndexHelper {
+
+  private LuceneIndexHelper() {
+
+  }
+
+  public static void fieldShouldExistInIndex(IndexSearcher searcher, String field) throws IOException {
+    CollectionStatistics idFieldStatistics = searcher.collectionStatistics(field);
+    if (idFieldStatistics.docCount() == 0) {
+      throw new IllegalArgumentException("Field '" + field + "' does not exist in the index");
+    }
+  }
+
+}