Java tutorial
//////////////////////////////////////////////////////////////////////////////// // checkstyle: Checks Java source code for adherence to a set of rules. // Copyright (C) 2001-2016 the original author or authors. // // This library is free software; you can redistribute it and/or // modify it under the terms of the GNU Lesser General Public // License as published by the Free Software Foundation; either // version 2.1 of the License, or (at your option) any later version. // // This library is distributed in the hope that it will be useful, // but WITHOUT ANY WARRANTY; without even the implied warranty of // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU // Lesser General Public License for more details. // // You should have received a copy of the GNU Lesser General Public // License along with this library; if not, write to the Free Software // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA //////////////////////////////////////////////////////////////////////////////// package com.puppycrawl.tools.checkstyle.checks.javadoc; import java.io.ByteArrayInputStream; import java.io.File; import java.io.IOException; import java.io.InputStream; import java.util.HashMap; import java.util.Map; import org.antlr.v4.runtime.ANTLRInputStream; import org.antlr.v4.runtime.BaseErrorListener; import org.antlr.v4.runtime.CommonTokenStream; import org.antlr.v4.runtime.RecognitionException; import org.antlr.v4.runtime.Recognizer; import org.antlr.v4.runtime.tree.ParseTree; import org.antlr.v4.runtime.tree.TerminalNode; import org.antlr.v4.runtime.tree.TerminalNodeImpl; import com.google.common.base.CaseFormat; import com.google.common.base.Charsets; import com.google.common.io.Files; import com.puppycrawl.tools.checkstyle.grammars.javadoc.JavadocLexer; import com.puppycrawl.tools.checkstyle.grammars.javadoc.JavadocParser; import com.puppycrawl.tools.checkstyle.utils.JavadocUtils; /** * Generates source code of methods that build ParseTree of given Javadoc comments. * List text files in 'inputNames' array. Only one Javadoc comment should be in each file. * A text file should not contain '/*' at the beginning and '*/' at the end. * * This class is not stand-alone, it should be used in scope of Checkstyle project, * because it uses Javadoc parser, ANTLR classes, etc. Just copy this file to Checkstyle repo, * specify input file you are working on and execute it through 'main' method to generate * appropriate unit-test source code. */ public final class ExpectedParseTreeGenerator { private static String pathToInputs = "src/test/resources/com/puppycrawl/tools/checkstyle/grammars/javadoc/"; /** * Input files from main Checkstyle repo */ private static String[] inputNames = { "InputLeadingAsterisks.txt", }; private Map<String, Integer> variableCounters = new HashMap<>(); private ExpectedParseTreeGenerator() { } public static void main(String[] args) throws Exception { final ExpectedParseTreeGenerator generator = new ExpectedParseTreeGenerator(); for (String inputName : inputNames) { final File file = new File(pathToInputs + inputName); final ParseTree generatedTree = parseJavadocFromFile(file); final String filename = file.getName(); String treeName = filename; final String inputWord = "Input"; if (filename.indexOf(inputWord) >= 0) { treeName = filename.substring(filename.indexOf(inputWord) + inputWord.length()); if (treeName.lastIndexOf('.') >= 0) { treeName = treeName.substring(0, treeName.lastIndexOf('.')); } } System.out.println("public static ParseTree tree" + treeName + "()\n{"); final String id = generator.walk(generatedTree, "null"); generator.resetCounter(); System.out.println(" return " + id + ";\n}\n"); } } private static ParseTree parseJavadocFromFile(File file) throws IOException { final String content = Files.toString(file, Charsets.UTF_8); final InputStream in = new ByteArrayInputStream(content.getBytes(Charsets.UTF_8)); final ANTLRInputStream input = new ANTLRInputStream(in); final JavadocLexer lexer = new JavadocLexer(input); lexer.removeErrorListeners(); final BaseErrorListener errorListener = new FailOnErrorListener(); lexer.addErrorListener(errorListener); final CommonTokenStream tokens = new CommonTokenStream(lexer); final JavadocParser parser = new JavadocParser(tokens); parser.removeErrorListeners(); parser.addErrorListener(errorListener); return parser.javadoc(); } private void resetCounter() { variableCounters.clear(); } public String walk(ParseTree t, String parentObjectName) { final String className = t.getClass().getSimpleName(); String id = null; if (t instanceof TerminalNode) { final TerminalNodeImpl terminal = (TerminalNodeImpl) t; final int type = terminal.symbol.getType(); String tokenType = ""; if (type == -1) { tokenType = "EOF"; } else { tokenType = JavadocUtils.getTokenName(type); } String text = terminal.getText(); if ("\n".equals(text)) { text = "\\n"; } else if ("\t".equals(text)) { text = "\\t"; } else { text = text.replace("\"", "\\\""); } final int number = getVariableCounter(tokenType); id = CaseFormat.LOWER_UNDERSCORE.to(CaseFormat.LOWER_CAMEL, tokenType.toLowerCase()) + number; System.out.println(" CommonToken " + id + " = new CommonToken(JavadocTokenTypes." + tokenType + ", \"" + text + "\");"); } else { int number = getVariableCounter(className); id = CaseFormat.UPPER_CAMEL.to(CaseFormat.LOWER_CAMEL, className) + number++; System.out.println( " " + className + " " + id + " = new " + className + "(" + parentObjectName + ", 0);"); final int n = t.getChildCount(); for (int i = 0; i < n; i++) { final String childId = walk(t.getChild(i), id); System.out.println(" " + id + ".addChild(" + childId + ");"); } } return id; } private int getVariableCounter(String className) { int number = 0; if (variableCounters.containsKey(className)) { number = variableCounters.get(className) + 1; } variableCounters.put(className, number); return number; } private static class FailOnErrorListener extends BaseErrorListener { @Override public void syntaxError(Recognizer<?, ?> recognizer, Object offendingSymbol, int line, int charPositionInLine, String msg, RecognitionException e) { throw new RuntimeException("[" + line + ", " + charPositionInLine + "] " + msg); } } }