Add interface for freezing/thawing objects

This adds a new interface IFreezable, which denotes that your object
supports being 'frozen' (immutable) or 'thawed' (mutable). There is also
optional support for 'deep-freezing' objects, which disables the ability
to thaw them.

It also introduces a new exception called ObjectFrozen, which
implementations of IFreezable may or may not throw when you attempt to
modify a frozen object

1 files changed, 47 insertions, 0 deletions

diff --git a/src/main/java/bjc/funcdata/ObjectFrozen.java b/src/main/java/bjc/funcdata/ObjectFrozen.java
new file mode 100644
index 0000000..2260a0e
--- /dev/null
+++ b/src/main/java/bjc/funcdata/ObjectFrozen.java
@@ -0,0 +1,47 @@
+package bjc.funcdata;
+
+/**
+ * Exception that implementations of {@link IFreezable} can throw if you attempt
+ * to modify a frozen object.
+ * 
+ * @author Ben Culkin
+ *
+ */
+public class ObjectFrozen extends RuntimeException {
+	private static final long serialVersionUID = -1567447627139090728L;
+
+	/**
+	 * Create a new ObjectFrozen exception.
+	 */
+	public ObjectFrozen() {
+		super();
+	}
+
+	/**
+	 * Create a new ObjectFrozen exception.
+	 * 
+	 * @param message The message of the exception.
+	 */
+	public ObjectFrozen(String message) {
+		super(message);
+	}
+
+	/**
+	 * Create a new ObjectFrozen exception.
+	 * 
+	 * @param cause The root cause of this exception.
+	 */
+	public ObjectFrozen(Throwable cause) {
+		super(cause);
+	}
+
+	/**
+	 * Create a new ObjectFrozen exception.
+	 * 
+	 * @param message The message of the exception.
+	 * @param cause The root cause of this exception.
+	 */
+	public ObjectFrozen(String message, Throwable cause) {
+		super(message, cause);
+	}
+}