Java example source code file (Node.java)

This example Java source code file (Node.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, commentnode, context, error, internal, iterator, list, node, runtimeexception, sending, should, string, stringbuffer, util, wrong

The Node.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.*;

abstract class Node {

    String kind;
    List<Node> components;
    int lineno;
    List<String> commentList = new ArrayList<>();
    Node parent = null;
    Context context = null;

    static final int maxStructIndent = 5;
    static int structIndent = 0; // horrible hack

    abstract void document(PrintWriter writer);

    void set(String kind, List<Node> components, int lineno) {
        this.kind = kind;
        this.components = components;
        this.lineno = lineno;
    }

    void parentAndExtractComments() {
        for (Iterator<Node> it = components.iterator(); it.hasNext();) {
            Node node = it.next();
            if (node instanceof CommentNode) {
                it.remove();
                commentList.add(((CommentNode)node).text());
            } else {
                node.parent = this;
                node.parentAndExtractComments();
            }
        }
    }

    void prune() {
        for (Node node : components) {
            node.prune();
        }
    }

    void constrain(Context ctx) {
        context = ctx;
        for (Node node : components) {
            constrainComponent(ctx, node);
        }
    }

    void constrainComponent(Context ctx, Node node) {
        node.constrain(ctx);
    }

    void indent(PrintWriter writer, int depth) {
        for (int i = 0; i < depth; i++) {
            writer.print("    ");
        }
    }

    void documentIndex(PrintWriter writer) {
    }

    void docRowStart(PrintWriter writer) {
        writer.println("<tr>");
        if (structIndent > 0) {
            writer.println("<td colspan=" + structIndent + ">");
        }
    }

    String comment() {
        StringBuffer comment = new StringBuffer();
        for (String st : commentList) {
            comment.append(st);
        }
        return comment.toString();
    }

    void genJavaComment(PrintWriter writer, int depth) {
        if (commentList.size() > 0) {
            indent(writer, depth);
            writer.println("/**");
            for (String comment : commentList) {
                indent(writer, depth);
                writer.println(" * " + comment);
            }
            indent(writer, depth);
            writer.println(" */");
        }
    }

    String javaType() {
        return "-- WRONG ---";
    }

    void genJava(PrintWriter writer, int depth) {
        for (Node node : components) {
            node.genJava(writer, depth);
        }
    }

    void genCInclude(PrintWriter writer) {
        for (Node node : components) {
            node.genCInclude(writer);
        }
    }

    String debugValue(String label) {
        return label;
    }

    void genJavaDebugWrite(PrintWriter writer, int depth,
                           String writeLabel) {
        genJavaDebugWrite(writer, depth, writeLabel, debugValue(writeLabel));
    }

    void genJavaDebugWrite(PrintWriter writer, int depth,
                           String writeLabel, String displayValue) {
        if (!Main.genDebug) {
            return;
        }
        indent(writer, depth);
        writer.println(
          "if ((ps.vm.traceFlags & VirtualMachineImpl.TRACE_SENDS) != 0) {");
        indent(writer, depth+1);
        writer.print("ps.vm.printTrace(\"Sending: ");
        indent(writer, depth);  // this is inside the quotes
        writer.print(writeLabel + "(" + javaType() + "): \" + ");
        writer.println(displayValue + ");");
        indent(writer, depth);
        writer.println("}");
    }

    public void genJavaRead(PrintWriter writer, int depth,
                            String readLabel) {
        error("Internal - Should not call Node.genJavaRead()");
    }

    void genJavaDebugRead(PrintWriter writer, int depth,
                          String readLabel, String displayValue) {
        if (!Main.genDebug) {
            return;
        }
        indent(writer, depth);
        writer.println(
          "if (vm.traceReceives) {");
        indent(writer, depth+1);
        writer.print("vm.printReceiveTrace(" + depth + ", \"");
        writer.print(readLabel + "(" + javaType() + "): \" + ");
        writer.println(displayValue + ");");
        indent(writer, depth);
        writer.println("}");
    }

    void genJavaPreDef(PrintWriter writer, int depth) {
        for (Node node : components) {
            node.genJavaPreDef(writer, depth);
        }
    }

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