Disposable.

2 files changed, 51 insertions, 0 deletions

diff --git a/src/uk/ac/ox/cs/pagoda/util/disposable/Disposable.java b/src/uk/ac/ox/cs/pagoda/util/disposable/Disposable.java
new file mode 100644
index 0000000..b208cc3
--- /dev/null
+++ b/src/uk/ac/ox/cs/pagoda/util/disposable/Disposable.java
@@ -0,0 +1,39 @@
+package uk.ac.ox.cs.pagoda.util.disposable;
+
+
+/**
+ * Every public method of a subclass of this class,
+ * as first instruction, should check if the object has already been disposed
+ * and, if so, should throw a <tt>DisposedException</tt>.
+ */
+public abstract class Disposable {
+
+    private boolean disposed = false;
+
+    /**
+     * This method must be called after the use of the object.
+     * <p>
+     * Every overriding method must call <tt>super.dispose()</tt> as first instruction.
+     */
+    public void dispose() {
+        if(isDisposed()) throw new AlreadyDisposedException();
+        disposed = true;
+    }
+
+    public final boolean isDisposed() {
+        return disposed;
+    }
+
+    private class AlreadyDisposedException extends RuntimeException {
+
+        public AlreadyDisposedException() {
+            super();
+        }
+
+        public AlreadyDisposedException(String msg) {
+            super(msg);
+        }
+    }
+
+
+}
diff --git a/src/uk/ac/ox/cs/pagoda/util/disposable/DisposedException.java b/src/uk/ac/ox/cs/pagoda/util/disposable/DisposedException.java
new file mode 100644
index 0000000..eb8c039
--- /dev/null
+++ b/src/uk/ac/ox/cs/pagoda/util/disposable/DisposedException.java
@@ -0,0 +1,12 @@
+package uk.ac.ox.cs.pagoda.util.disposable;
+
+public class DisposedException extends RuntimeException {
+
+    public DisposedException() {
+        super();
+    }
+
+    public DisposedException(String msg) {
+        super(msg);
+    }
+}