LUCENE-5635: add CrankyTokenFilter

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/trunk@1591605 13f79535-47bb-0310-9956-ffa450edef68

lucene/test-framework/src/java/org/apache/lucene/analysis/CrankyTokenFilter.java

@@ -0,0 +1,71 @@
+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 java.io.IOException;
+import java.util.Random;
+
+/** 
+ * Throws IOException from random Tokenstream methods.
+ * <p>
+ * This can be used to simulate a buggy analyzer in IndexWriter,
+ * where we must delete the document but not abort everything in the buffer.
+ */
+public class CrankyTokenFilter extends TokenFilter {
+  final Random random;
+  int thingToDo;
+  
+  /** Creates a new CrankyTokenFilter */
+  public CrankyTokenFilter(TokenStream input, Random random) {
+    super(input);
+    this.random = random;
+  }
+
+  @Override
+  public boolean incrementToken() throws IOException {
+    if (thingToDo == 0 && random.nextBoolean()) {
+      throw new IOException("Fake IOException from TokenStream.incrementToken()");
+    }
+    return input.incrementToken();
+  }
+  
+  @Override
+  public void end() throws IOException {
+    super.end();
+    if (thingToDo == 1 && random.nextBoolean()) {
+      throw new IOException("Fake IOException from TokenStream.end()");
+    }
+  }
+  
+  @Override
+  public void reset() throws IOException {
+    super.reset();
+    thingToDo = random.nextInt(10);
+    if (thingToDo == 2 && random.nextBoolean()) {
+      throw new IOException("Fake IOException from TokenStream.reset()");
+    }
+  }
+
+  @Override
+  public void close() throws IOException {
+    super.close();
+    if (thingToDo == 3 && random.nextBoolean()) {
+      throw new IOException("Fake IOException from TokenStream.close()");
+    }
+  }
+}