/* * 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. */ package org.apache.cassandra.cql3; import org.antlr.runtime.ANTLRStringStream; import org.antlr.runtime.CharStream; import org.antlr.runtime.CommonTokenStream; import org.antlr.runtime.RecognitionException; import org.antlr.runtime.TokenStream; import org.apache.cassandra.exceptions.SyntaxException; /** * Helper class to encapsulate common code that calls one of the generated methods in {@code CqlParser}. */ public final class CQLFragmentParser { @FunctionalInterface public interface CQLParserFunction<R> { R parse(CqlParser parser) throws RecognitionException; } public static <R> R parseAny(CQLParserFunction<R> parserFunction, String input, String meaning) { try { return parseAnyUnhandled(parserFunction, input); } catch (RuntimeException re) { throw new SyntaxException(String.format("Failed parsing %s: [%s] reason: %s %s", meaning, input, re.getClass().getSimpleName(), re.getMessage())); } catch (RecognitionException e) { throw new SyntaxException("Invalid or malformed " + meaning + ": " + e.getMessage()); } } /** * Just call a parser method in {@link CqlParser} - does not do any error handling. */ public static <R> R parseAnyUnhandled(CQLParserFunction<R> parserFunction, String input) throws RecognitionException { // Lexer and parser ErrorCollector errorCollector = new ErrorCollector(input); CharStream stream = new ANTLRStringStream(input); CqlLexer lexer = new CqlLexer(stream); lexer.addErrorListener(errorCollector); TokenStream tokenStream = new CommonTokenStream(lexer); CqlParser parser = new CqlParser(tokenStream); parser.addErrorListener(errorCollector); // Parse the query string to a statement instance R r = parserFunction.parse(parser); // The errorCollector has queue up any errors that the lexer and parser may have encountered // along the way, if necessary, we turn the last error into exceptions here. errorCollector.throwFirstSyntaxError(); return r; } }