1 files changed, 49 insertions, 0 deletions
diff --git a/src/main/java/org/openslx/util/TimeoutReference.java b/src/main/java/org/openslx/util/TimeoutReference.java
new file mode 100644
index 0000000..4d7a992
--- /dev/null
+++ b/src/main/java/org/openslx/util/TimeoutReference.java
@@ -0,0 +1,49 @@
+package org.openslx.util;
+
+/**
+ * A reference holder that will only return the object it is holding if
+ * the given timeout has not been reached.
+ * The timeout will start anew if you set this reference to hold a new object,
+ * or if you retrieve the object, and refreshOnGet is set to true.
+ */
+public class TimeoutReference<T>
+{
+
+	private final long timeoutMs;
+	private long deadline;
+	private boolean refreshOnGet;
+	private T item;
+
+	public TimeoutReference( boolean refreshOnGet, long timeoutMs, T item )
+	{
+		this.refreshOnGet = refreshOnGet;
+		this.item = item;
+		this.timeoutMs = timeoutMs;
+		this.deadline = System.currentTimeMillis() + timeoutMs;
+	}
+
+	public TimeoutReference( long timeoutMs, T item )
+	{
+		this( false, timeoutMs, item );
+	}
+
+	public synchronized T get()
+	{
+		if ( item != null ) {
+			final long now = System.currentTimeMillis();
+			if ( deadline < now ) {
+				item = null;
+			} else if ( refreshOnGet ) {
+				deadline = now + timeoutMs;
+			}
+		}
+		return item;
+	}
+
+	public synchronized void set( T newItem )
+	{
+		this.item = newItem;
+		this.deadline = System.currentTimeMillis() + timeoutMs;
+	}
+
+}