| /* |
| * Copyright 2016-present Open Networking Laboratory |
| * |
| * 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 org.onosproject.yangutils.parser.impl; |
| |
| import java.io.IOException; |
| |
| import org.antlr.v4.runtime.ANTLRFileStream; |
| import org.antlr.v4.runtime.ANTLRInputStream; |
| import org.antlr.v4.runtime.CommonTokenStream; |
| import org.antlr.v4.runtime.tree.ParseTree; |
| import org.antlr.v4.runtime.tree.ParseTreeWalker; |
| import org.onosproject.yangutils.datamodel.YangNode; |
| import org.onosproject.yangutils.parser.YangUtilsParser; |
| import org.onosproject.yangutils.parser.antlrgencode.GeneratedYangLexer; |
| import org.onosproject.yangutils.parser.antlrgencode.GeneratedYangParser; |
| import org.onosproject.yangutils.parser.exceptions.ParserException; |
| import org.onosproject.yangutils.parser.impl.parserutils.ParseTreeErrorListener; |
| |
| /** |
| * Represents file parsing, parse tree creation and data model tree creation |
| * corresponding to an input YANG file. |
| */ |
| public class YangUtilsParserManager implements YangUtilsParser { |
| |
| @Override |
| public YangNode getDataModel(String yangFile) throws IOException, ParserException { |
| |
| /** |
| * Create a char stream that reads from YANG file. Throws an exception |
| * in case input YANG file is either null or non existent. |
| */ |
| ANTLRInputStream input; |
| try { |
| input = new ANTLRFileStream(yangFile); |
| } catch (IOException e) { |
| throw new ParserException("YANG file error : YANG file does not exist."); |
| } |
| |
| // Create a lexer that feeds off of input char stream. |
| GeneratedYangLexer lexer = new GeneratedYangLexer(input); |
| |
| // Create a buffer of tokens pulled from the lexer. |
| CommonTokenStream tokens = new CommonTokenStream(lexer); |
| |
| // Create a parser that feeds off the tokens buffer. |
| GeneratedYangParser parser = new GeneratedYangParser(tokens); |
| |
| // Remove console error listener. |
| parser.removeErrorListeners(); |
| |
| // Create instance of customized error listener. |
| ParseTreeErrorListener parseTreeErrorListener = new ParseTreeErrorListener(); |
| |
| // Add customized error listener to catch errors during parsing. |
| parser.addErrorListener(parseTreeErrorListener); |
| |
| ParseTree tree; |
| |
| try { |
| // Begin parsing YANG file and generate parse tree. |
| tree = parser.yangfile(); |
| } catch (ParserException parserException) { |
| parserException.setFileName(yangFile); |
| throw parserException; |
| } |
| |
| // Create a walker to walk the parse tree. |
| ParseTreeWalker walker = new ParseTreeWalker(); |
| |
| // Create a listener implementation class object. |
| TreeWalkListener treeWalker = new TreeWalkListener(); |
| |
| /** |
| * Walk parse tree, provide call backs to methods in listener and build |
| * data model tree. |
| */ |
| try { |
| walker.walk(treeWalker, tree); |
| } catch (ParserException listenerException) { |
| // TODO free incomplete data model tree. |
| listenerException.setFileName(yangFile); |
| throw listenerException; |
| } finally { |
| // TODO free parsable stack |
| } |
| |
| // Returns the Root Node of the constructed data model tree. |
| return treeWalker.getRootNode(); |
| } |
| } |