Java tutorial
/* * Yet Another UserAgent Analyzer * Copyright (C) 2013-2017 Niels Basjes * * Licensed 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 nl.basjes.parse.useragent.utils; import org.antlr.v4.runtime.CharStream; import org.antlr.v4.runtime.ParserRuleContext; import org.antlr.v4.runtime.misc.Interval; import org.antlr.v4.runtime.tree.ParseTree; import org.antlr.v4.runtime.tree.RuleNode; public final class AntlrUtils { private AntlrUtils() { } public static String getSourceText(ParserRuleContext ctx) { if (ctx.start == null) { return null; // Invalid } if (ctx.stop == null) { return ctx.getText(); } int startIndex = ctx.start.getStartIndex(); int stopIndex = ctx.stop.getStopIndex(); if (stopIndex < startIndex) { return ctx.getText(); } CharStream inputStream = ctx.start.getInputStream(); return inputStream.getText(new Interval(startIndex, stopIndex)); } public static String getSourceText(RuleNode ruleNode) { if (ruleNode instanceof ParserRuleContext) { return getSourceText((ParserRuleContext) ruleNode); } return ruleNode.getText(); } public static String getSourceText(ParseTree ruleNode) { if (ruleNode instanceof ParserRuleContext) { return getSourceText((ParserRuleContext) ruleNode); } return ruleNode.getText(); } }