extracted common parts of the tokenizing filters to create the AbstractTokenizingFilter

Former-commit-id: 5ecb6ad7f16de5d9a22789b4cfbbf38c40a8fb35

src/main/java/org/owasp/dependencycheck/data/lucene/AbstractTokenizingFilter.java

@@ -0,0 +1,80 @@
+/*
+ * This file is part of Dependency-Check.
+ *
+ * Dependency-Check is free software: you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation, either version 3 of the License, or (at your option) any
+ * later version.
+ *
+ * Dependency-Check is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
+ * details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * Dependency-Check. If not, see http://www.gnu.org/licenses/.
+ *
+ * Copyright (c) 2013 Jeremy Long. All Rights Reserved.
+ */
+package org.owasp.dependencycheck.data.lucene;
+
+import java.util.LinkedList;
+import org.apache.lucene.analysis.TokenFilter;
+import org.apache.lucene.analysis.TokenStream;
+import org.apache.lucene.analysis.tokenattributes.CharTermAttribute;
+
+/**
+ * An abstract tokenizing filter that can be used as the base for a tokenizing
+ * filter.
+ *
+ * @author Jeremy Long (jeremy.long@gmail.com)
+ */
+public abstract class AbstractTokenizingFilter extends TokenFilter {
+
+    /**
+     * The char term attribute.
+     */
+    private final CharTermAttribute termAtt = addAttribute(CharTermAttribute.class);
+    /**
+     * Gets the CharTermAttribute.
+     * @return the CharTermAttribute
+     */
+    protected CharTermAttribute getTermAtt() {
+        return termAtt;
+    }
+    /**
+     * A collection of tokens to add to the stream.
+     */
+    private final LinkedList<String> tokens;
+    /**
+     * Gets the list of tokens.
+     * @return the list of tokens
+     */
+    protected LinkedList<String> getTokens() {
+        return tokens;
+    }
+    /**
+     * Constructs a new AbstractTokenizingFilter.
+     *
+     * @param stream the TokenStream that this filter will process
+     */
+    public AbstractTokenizingFilter(TokenStream stream) {
+        super(stream);
+        tokens = new LinkedList<String>();
+    }
+
+    /**
+     * Adds a term, if one exists, from the tokens collection.
+     *
+     * @return whether or not a new term was added
+     */
+    protected boolean addTerm() {
+        final boolean termAdded = tokens.size() > 0;
+        if (termAdded) {
+            final String version = tokens.pop();
+            clearAttributes();
+            termAtt.append(version);
+        }
+        return termAdded;
+    }
+}