public void execute(String query) throws ParseException {
    reset();
    query = query.replaceAll("\\s+AND\\s+", " and ");
    query = query.replaceAll("\\s+OR\\s+", " or ");
    query = query.replaceAll("\\s+NOT\\s+", " not ");

    // Check to see if its in the cache
    Hash hash = MurmurHash.getInstance();
    this.hashVal = hash.hash(query.getBytes(), SEED);
    CacheEntry entry = null;
    synchronized (cache) {
        entry = (CacheEntry) cache.get(hashVal);
    }
    if (entry != null) {
        this.negatedTerms = entry.getNegatedTerms();
        this.andTerms = entry.getAndTerms();
        this.orTerms = entry.getOrTerms();
        this.literals = entry.getLiterals();
        this.terms = entry.getTerms();
        this.rootNode = entry.getRootNode();
        this.tree = entry.getTree();
    } else {
        Parser p = new Parser(new StringReader(";"));
        rootNode = p.parse(new StringReader(query), null);
        rootNode.childrenAccept(this, null);
        TreeBuilder builder = new TreeBuilder(rootNode);
        tree = builder.getRootNode();
        entry = new CacheEntry(this.negatedTerms, this.andTerms, this.orTerms, this.literals, this.terms, rootNode, tree);
        synchronized (cache) {
            cache.put(hashVal, entry);
        }
    }

}