Java tutorial
/* * Copyright 2015 by Thomas Lottermann * * 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 notaql.engines.csv.path; import notaql.model.path.InputPath; import notaql.model.path.InputPathStep; import notaql.parser.NotaQLErrorListener; import notaql.parser.TransformationParser; import notaql.parser.antlr.NotaQL2CSVInLexer; import notaql.parser.antlr.NotaQL2CSVInParser; import notaql.parser.path.InputPathParser; import org.antlr.v4.runtime.ANTLRInputStream; import org.antlr.v4.runtime.CommonTokenStream; import java.util.LinkedList; import java.util.List; /** * Parses CSV input paths */ public class CSVInputPathParser implements InputPathParser { private final TransformationParser transformationParser; public CSVInputPathParser(TransformationParser parser) { this.transformationParser = parser; } @Override public InputPath parse(String enginePath, boolean relative) { final NotaQL2CSVInLexer lexer = new NotaQL2CSVInLexer(new ANTLRInputStream(enginePath)); final NotaQL2CSVInParser parser = new NotaQL2CSVInParser(new CommonTokenStream(lexer)); parser.addErrorListener(new NotaQLErrorListener(parser)); final NotaQL2CSVInParser.InputPathContext inputPathContext = parser.inputPath(); final List<InputPathStep> steps = new LinkedList<>( new CSVInputPathVisitor(transformationParser, relative).visit(inputPathContext).getPathSteps()); return new InputPath(relative, steps); } }