1 files changed, 101 insertions, 0 deletions
diff --git a/project/JavaCommon/src/com/modulus/common/collections/ArrayStack.java b/project/JavaCommon/src/com/modulus/common/collections/ArrayStack.java
new file mode 100644
index 0000000..17dfcb1
--- /dev/null
+++ b/project/JavaCommon/src/com/modulus/common/collections/ArrayStack.java
@@ -0,0 +1,101 @@
+package com.modulus.common.collections;
+
+import java.io.Serializable;
+
+/**
+ * Class which uses an array to be used to
+ * implement a stack.
+ * 
+ * This class is most efficient for
+ * nearly every purpose.
+ * 
+ * @author jrahm
+ *
+ * @param <T> the type this stack holds
+ */
+public class ArrayStack<T> implements Stack<T>, Serializable{
+	
+	private Object[] arr;
+	private int pointer = -1;
+	
+	/**
+	 * Creates a new ArrayStack with a
+	 * default starting size of 10
+	 */
+	public ArrayStack(){
+		this(10);
+	}
+	
+	/**
+	 * Creates a new ArrayStack with
+	 * a default starting size of <code>size</code>
+	 * @param size
+	 */
+	public ArrayStack( int size ){
+		arr = new Object[size];
+	}
+	
+	/**
+	 * Ensures that this ArrayStack has enough space
+	 * to store <code>size</code> number of elements.
+	 * 
+	 * @param size the number of elements needed to store
+	 */
+	public void ensureSize( int size ){
+
+		if(arr.length > size)
+			return;
+		
+		Object[] tmp = new Object[size*2];
+		for ( int i = 0;i < arr.length; i ++ ){
+			tmp[i] = arr[i];
+		}
+		
+		arr = tmp;
+	}
+
+	@Override
+	public boolean isEmpty() {
+		return pointer == -1;
+	}
+
+	@SuppressWarnings("unchecked")
+	@Override
+	public T peek() {
+		return (T)arr[pointer];
+	}
+
+	@SuppressWarnings("unchecked")
+	@Override
+	public T pop() {
+		return (T) arr[ pointer -- ];
+	}
+
+	@Override
+	public void push(T obj) {
+		pointer ++;
+		this.ensureSize(pointer);
+		arr[pointer] = obj;
+	}
+
+	@Override
+	public int size() {
+		return pointer + 1;
+	}
+	
+	@Override
+	public void clear(){
+		pointer = 0;
+	}
+	
+	@Override
+	public String toString(){
+		StringBuffer buf = new StringBuffer("[");
+		
+		for( int i = pointer; i >= 1; i --)
+			buf.append(arr[i] + ", ");
+		
+		buf.append(arr[0] + "]");
+		return buf.toString();
+	}
+}