MyStackDemo.java Source code

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Here is the source code for MyStackDemo.java

Source

/*
 * Copyright (c) Ian F. Darwin, http://www.darwinsys.com/, 1996-2002.
 * All rights reserved. Software written by Ian F. Darwin and others.
 * $Id: LICENSE,v 1.8 2004/02/09 03:33:38 ian Exp $
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS''
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 * 
 * Java, the Duke mascot, and all variants of Sun's Java "steaming coffee
 * cup" logo are trademarks of Sun Microsystems. Sun's, and James Gosling's,
 * pioneering role in inventing and promulgating (and standardizing) the Java 
 * language and environment is gratefully acknowledged.
 * 
 * The pioneering role of Dennis Ritchie and Bjarne Stroustrup, of AT&T, for
 * inventing predecessor languages C and C++ is also gratefully acknowledged.
 */
public class MyStackDemo {
    public static void main(String[] args) {
        MyStack<String> ms1 = new MyStack<String>();
        ms1.push("billg");
        ms1.push("scottm");

        while (ms1.hasNext()) {
            String name = ms1.pop();
            System.out.println(name);
        }

        // Old way of using Collections: not type safe.
        MyStack ms2 = new MyStack();
        ms2.push("billg"); // EXPECT WARNING
        ms2.push("scottm"); // EXPECT WARNING
        ms2.push(new java.util.Date()); // EXPECT WARNING

        // Show that it is broken 
        try {
            String bad = (String) ms2.pop();
            System.err.println("Didn't get expected exception!");
        } catch (ClassCastException ex) {
            System.out.println("Did get expected exception.");
        }

        // Removed the brokenness, print rest of it.
        while (ms2.hasNext()) {
            String name = (String) ms2.pop();
            System.out.println(name);
        }
    }
}

/** A lax Stack implementation.
 * @version $Id: MyStack.java,v 1.4 2004/03/07 23:18:59 ian Exp $
 */
class MyStack<T> {
    private int ix = 0;
    public static final int MAX = 10;
    private T[] data = (T[]) new Object[MAX];

    public void push(T obj) {
        data[ix++] = obj;
    }

    public boolean hasNext() {
        return ix > 0;
    }

    public boolean hasRoom() {
        return ix < MAX;
    }

    public T pop() {
        if (hasNext()) {
            return data[--ix];
        }
        throw new ArrayIndexOutOfBoundsException(-1);
    }
}