DefaultQueryCompiler.java 文件源码

/**
 * <p>Create an Elasticsearch query for the given search string but does
 * not apply the {@link ElasticsearchQueryOptimizer} to it.</p>
 * @param search the search string
 * @return the Elasticsearch query (may be null)
 */
protected JsonObject compileQueryNoOptimize(String search) {
  if (search == null || search.isEmpty()) {
    // match everything by default
    return matchAllQuery();
  }

  // parse query
  QueryLexer lexer = new QueryLexer(new ANTLRInputStream(search.trim()));
  CommonTokenStream tokens = new CommonTokenStream(lexer);
  QueryParser parser = new QueryParser(tokens);
  QueryContext ctx = parser.query();

  // compile query to QueryBuilder
  QueryCompilerListener listener = new QueryCompilerListener();
  ParseTreeWalker.DEFAULT.walk(listener, ctx);

  if (listener.result.isEmpty()) {
    return matchAllQuery();
  }
  return listener.result.pop();
}