Java example source code file (Parse.java)

This example Java source code file (Parse.java) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Learn more about this Java project at its project page.

Java - Java tags/keywords

arraylist, commandset, error, expected, hashmap, ioexception, list, namevaluenode, node, parse, referenceidtypenode, rootnode, streamtokenizer, string, util

The Parse.java Java example source code

/*
 * Copyright (c) 1998, 2013, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code 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 General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

package build.tools.jdwpgen;

import java.util.*;
import java.io.*;

class Parse {

    final StreamTokenizer izer;
    final Map<String, Node> kindMap = new HashMap();

    Parse(Reader reader) {
        izer = new StreamTokenizer(new BufferedReader(reader));
        izer.resetSyntax();
        izer.slashStarComments(true);
        izer.slashSlashComments(true);
        izer.wordChars((int)'a', (int)'z');
        izer.wordChars((int)'A', (int)'Z');
        izer.wordChars((int)'0', (int)'9');
        izer.wordChars((int)'_', (int)'_');
        izer.wordChars((int)'-', (int)'-');
        izer.wordChars((int)'.', (int)'.');
        izer.whitespaceChars(0, 32);
        izer.quoteChar('"');
        izer.quoteChar('\'');

        kindMap.put("CommandSet", new CommandSetNode());
        kindMap.put("Command", new CommandNode());
        kindMap.put("Out", new OutNode());
        kindMap.put("Reply", new ReplyNode());
        kindMap.put("ErrorSet", new ErrorSetNode());
        kindMap.put("Error", new ErrorNode());
        kindMap.put("Event", new EventNode());
        kindMap.put("Repeat", new RepeatNode());
        kindMap.put("Group", new GroupNode());
        kindMap.put("Select", new SelectNode());
        kindMap.put("Alt", new AltNode());
        kindMap.put("ConstantSet", new ConstantSetNode());
        kindMap.put("Constant", new ConstantNode());
        kindMap.put("int", new IntTypeNode());
        kindMap.put("long", new LongTypeNode());
        kindMap.put("boolean", new BooleanTypeNode());
        kindMap.put("object", new ObjectTypeNode());
        kindMap.put("threadObject", new ThreadObjectTypeNode());
        kindMap.put("threadGroupObject", new ThreadGroupObjectTypeNode());
        kindMap.put("arrayObject", new ArrayObjectTypeNode());
        kindMap.put("stringObject", new StringObjectTypeNode());
        kindMap.put("classLoaderObject", new ClassLoaderObjectTypeNode());
        kindMap.put("classObject", new ClassObjectTypeNode());
        kindMap.put("referenceType", new ReferenceTypeNode());
        kindMap.put("referenceTypeID", new ReferenceIDTypeNode());
        kindMap.put("classType", new ClassTypeNode());
        kindMap.put("interfaceType", new InterfaceTypeNode());
        kindMap.put("arrayType", new ArrayTypeNode());
        kindMap.put("method", new MethodTypeNode());
        kindMap.put("field", new FieldTypeNode());
        kindMap.put("frame", new FrameTypeNode());
        kindMap.put("string", new StringTypeNode());
        kindMap.put("value", new ValueTypeNode());
        kindMap.put("byte", new ByteTypeNode());
        kindMap.put("location", new LocationTypeNode());
        kindMap.put("tagged-object", new TaggedObjectTypeNode());
        kindMap.put("referenceTypeID", new ReferenceIDTypeNode());
        kindMap.put("typed-sequence", new ArrayRegionTypeNode());
        kindMap.put("untagged-value", new UntaggedValueTypeNode());
    }

    RootNode items() throws IOException {
        List<Node> list = new ArrayList();

        while (izer.nextToken() != StreamTokenizer.TT_EOF) {
            izer.pushBack();
            list.add(item());
        }
        RootNode node =  new RootNode();
        node.set("Root", list, 1);
        return node;
    }

    Node item() throws IOException {
        switch (izer.nextToken()) {
            case StreamTokenizer.TT_EOF:
                error("Unexpect end-of-file");
                return null;

            case StreamTokenizer.TT_WORD: {
                String name = izer.sval;
                if (izer.nextToken() == '=') {
                    int ntok = izer.nextToken();
                    if (ntok == StreamTokenizer.TT_WORD) {
                        return new NameValueNode(name, izer.sval);
                    } else if (ntok == '\'') {
                        return new NameValueNode(name, izer.sval.charAt(0));
                    } else {
                        error("Expected value after: " + name + " =");
                        return null;
                    }
                } else {
                    izer.pushBack();
                    return new NameNode(name);
                }
            }

            case '"':
                return new CommentNode(izer.sval);

            case '(': {
                if (izer.nextToken() == StreamTokenizer.TT_WORD) {
                    String kind = izer.sval;
                    List<Node> list = new ArrayList();

                    while (izer.nextToken() != ')') {
                        izer.pushBack();
                        list.add(item());
                    }
                    Node proto = kindMap.get(kind);
                    if (proto == null) {
                        error("Invalid kind: " + kind);
                        return null;
                    } else {
                        try {
                            Node node = (Node)proto.getClass().newInstance();
                            node.set(kind, list, izer.lineno());
                            return node;
                        } catch (InstantiationException exc) {
                            error(exc.toString());
                            return null;
                        } catch (IllegalAccessException exc) {
                            error(exc.toString());
                            return null;
                        }
                    }
                } else {
                    error("Expected kind identifier, got " + izer.ttype +
                          " : " + izer.sval);
                    return null;
                }
            }

            default:
                error("Unexpected character: '" + (char)izer.ttype + "'");
                return null;
        }
    }

    void error(String errmsg) {
        System.err.println(Main.specSource + ":" + izer.lineno() +
                           ": " + errmsg);
        throw new RuntimeException("Error: " + errmsg);
    }
}