diff --git a/src/main/java/ch/zhaw/ads/ListStack.java b/src/main/java/ch/zhaw/ads/ListStack.java
new file mode 100644
index 0000000..c476fbb
--- /dev/null
+++ b/src/main/java/ch/zhaw/ads/ListStack.java
@@ -0,0 +1,72 @@
+/**
+ * AnyServer -- Praktikum Experimentierkasten -- ADS
+ *
+ * @author E. Mumprecht
+ * @version 1.0 -- Geruest fuer irgendeinen Server
+ */
+package ch.zhaw.ads;
+
+public class ListStack implements CommandExecutor {
+
+    @Override
+    public String execute(String command) {
+        StringBuffer result = new StringBuffer(100);
+        result.append("Die Eingabe war \"");
+        result.append(command);
+        result.append("\"\n");
+        return result.toString();
+    }
+
+    Object[] data;
+    private int top;
+    private int capacity;
+    private static final int DEFAULT_CAPACITY = 100;
+
+    public ListStack() {
+        this(DEFAULT_CAPACITY);
+    }
+
+    public ListStack(int capacity) {
+        this.capacity= capacity;
+        removeAll();
+    }
+
+    public void removeAll() {
+        data = new Object[capacity];
+        top = 0;
+    }
+
+    public void push(Object x) {
+    // public void push(Object x) throws StackOverflowException {
+    //     if (isFull()){
+    //         throw new StackOverflowException();
+    //     }
+        data[top] = x;
+        top++;
+    }
+
+    public Object pop() {
+        if (isEmpty()){
+            return null;
+        }
+        top--;
+        Object topItem= data [top];
+        data [top] = null;
+        return topItem;
+    }
+
+    public Object peek() {
+        if (isEmpty()){
+            return null;
+        }
+        return data [top-1];
+    }
+
+    public boolean isEmpty() {
+        return (top == 0);
+    }
+
+    public boolean isFull() {
+        return top == data.length;
+    }
+}
diff --git a/src/main/java/ch/zhaw/ads/StackOverflowException.java b/src/main/java/ch/zhaw/ads/StackOverflowException.java
new file mode 100644
index 0000000..4aae96e
--- /dev/null
+++ b/src/main/java/ch/zhaw/ads/StackOverflowException.java
@@ -0,0 +1,7 @@
+package ch.zhaw.ads;
+
+public class StackOverflowException extends Exception { 
+    public StackOverflowException(String errorMessage) {
+        super(errorMessage);
+    }
+}