Added BoundedHashMap.

spring-integration-core/src/main/java/org/springframework/integration/util/BoundedHashMap.java

@@ -0,0 +1,42 @@
+/*
+ * Copyright 2002-2008 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.integration.util;
+
+import java.util.LinkedHashMap;
+import java.util.Map.Entry;
+
+/**
+ * A Map implementation that enforces the specified capacity.
+ *  
+ * @author Mark Fisher
+ */
+public class BoundedHashMap<K, V> extends LinkedHashMap<K, V> {
+
+	private final long capacity;
+
+
+	public BoundedHashMap(long capacity) {
+		this.capacity = capacity;
+	}
+
+
+	@Override
+	protected boolean removeEldestEntry(Entry<K, V> eldest) {
+		return this.size() > this.capacity;
+	}
+
+}