Java example source code file (SelectNode.java)

This example Java source code file (SelectNode.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

abstractgroupnode, abstractsimpletypenode, altnode, bytetypenode, common, internal, inttypenode, iterator, node, select, selectnode, string, util

The SelectNode.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 SelectNode extends AbstractGroupNode implements TypeNode {

    AbstractSimpleTypeNode typeNode = null;

    void prune() {
        super.prune();
        Iterator<Node> it = components.iterator();

        if (it.hasNext()) {
            Node typeNode = it.next();

            if (typeNode instanceof ByteTypeNode ||
                      typeNode instanceof IntTypeNode) {
                this.typeNode = (AbstractSimpleTypeNode)typeNode;
                it.remove();
            } else {
                error("Select must be based on 'int' or 'byte'");
            }
        } else {
            error("empty");
        }
    }

    void constrain(Context ctx) {
        super.constrain(ctx);
        if (components.size() < 2) {
            error("Select must have at least two options");
        }
    }

    void constrainComponent(Context ctx, Node node) {
        node.constrain(ctx);
        if (!(node instanceof AltNode)) {
            error("Select must consist of selector followed by Alt items");
        }
    }

    void document(PrintWriter writer) {
        typeNode.document(writer);
        super.document(writer);
    }

    String docType() {
        // should never call this
        error("Internal - called SelectNode.docType()");
        return null;
    }

    String commonBaseClass() {
        return name() + "Common";
    }

    private String commonVar() {
        return " a" + commonBaseClass();
    }

    void genJavaClassSpecifics(PrintWriter writer, int depth) {
        indent(writer, depth);
        writer.println("abstract static class " + commonBaseClass() + " {");
        if (context.isWritingCommand()) {
            indent(writer, depth+1);
            writer.println("abstract void write(PacketStream ps);");
        } else {
            indent(writer, depth+1);
            writer.println("abstract " + typeNode.javaParam() + "();");
        }
        indent(writer, depth);
        writer.println("}");
        typeNode.genJavaDeclaration(writer, depth);
        indent(writer, depth);
        writer.println(commonBaseClass() + commonVar() + ";");
        super.genJavaClassSpecifics(writer, depth);
    }

    void genJavaClassBodyComponents(PrintWriter writer, int depth) {
        // don't naively include alt components
    }

    void genJavaWritingClassBody(PrintWriter writer, int depth,
                                 String className) {
        writer.println();
        indent(writer, depth);
        writer.print(className + "(" + typeNode.javaParam() + ", ");
        writer.print(commonBaseClass() + commonVar());
        writer.println(") {");
        indent(writer, depth+1);
        writer.println("this." + typeNode.name() + " = " + typeNode.name() + ";");
        indent(writer, depth+1);
        writer.println("this." + commonVar() + " =" + commonVar() + ";");
        indent(writer, depth);
        writer.println("}");
    }

    void genJavaWrites(PrintWriter writer, int depth) {
        typeNode.genJavaWrite(writer, depth, typeNode.name());
        indent(writer, depth);
        writer.println(commonVar() + ".write(ps);");
    }

    void genJavaReads(PrintWriter writer, int depth) {
        typeNode.genJavaRead(writer, depth, typeNode.name());
        indent(writer, depth);
        writer.println("switch (" + typeNode.name() + ") {");
        for (Node node : components) {
            AltNode alt = (AltNode)node;
            alt.genJavaReadsSelectCase(writer, depth+1, commonVar());
        }
        indent(writer, depth);
        writer.println("}");
    }

    public void genJavaDeclaration(PrintWriter writer, int depth) {
        typeNode.genJavaDeclaration(writer, depth);
        super.genJavaDeclaration(writer, depth);
    }

    public String javaParam() {
        return typeNode.javaParam() + ", " + name() + " a" + name();
    }
}