INT-4422: No MessagingException in SimplePool

JIRA: https://jira.spring.io/browse/INT-4422

Inappropriate exception type, there is no message in the context of the pool.

Add a new exception.

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

@@ -0,0 +1,37 @@
+/*
+ * Copyright 2018 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;
+
+/**
+ * Thrown when a pooled item could not be obtained for some reason.
+ *
+ * @author Gary Russell
+ * @since 5.1
+ *
+ */
+@SuppressWarnings("serial")
+public class PoolItemNotAvailableException extends RuntimeException {
+
+	public PoolItemNotAvailableException(String message, Throwable cause) {
+		super(message, cause);
+	}
+
+	public PoolItemNotAvailableException(String message) {
+		super(message);
+	}
+
+}

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -28,7 +28,6 @@ import java.util.concurrent.atomic.AtomicInteger;
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 
-import org.springframework.messaging.MessagingException;
 import org.springframework.util.Assert;
 
 /**
@@ -155,7 +154,7 @@ public class SimplePool<T> implements Pool<T> {
 
 	/**
 	 * Obtains an item from the pool; waits up to waitTime milliseconds (default infinity).
-	 * @throws MessagingException if no items become available in time.
+	 * @throws PoolItemNotAvailableException if no items become available in time.
 	 */
 	@Override
 	public T getItem() {
@@ -166,10 +165,10 @@ public class SimplePool<T> implements Pool<T> {
 			}
 			catch (InterruptedException e) {
 				Thread.currentThread().interrupt();
-				throw new MessagingException("Interrupted awaiting a pooled resource", e);
+				throw new PoolItemNotAvailableException("Interrupted awaiting a pooled resource", e);
 			}
 			if (!permitted) {
-				throw new IllegalStateException("Timed out while waiting to acquire a pool entry.");
+				throw new PoolItemNotAvailableException("Timed out while waiting to acquire a pool entry.");
 			}
 			return doGetItem();
 		}
@@ -177,10 +176,10 @@ public class SimplePool<T> implements Pool<T> {
 			if (permitted) {
 				this.permits.release();
 			}
-			if (e instanceof MessagingException) {
-				throw (MessagingException) e;
+			if (e instanceof PoolItemNotAvailableException) {
+				throw (PoolItemNotAvailableException) e;
 			}
-			throw new MessagingException("Failed to obtain pooled item", e);
+			throw new PoolItemNotAvailableException("Failed to obtain pooled item", e);
 		}
 	}
 

spring-integration-core/src/test/java/org/springframework/integration/util/SimplePoolTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -30,7 +30,6 @@ import java.util.concurrent.atomic.AtomicBoolean;
 import org.junit.Test;
 
 import org.springframework.integration.test.util.TestUtils;
-import org.springframework.messaging.MessagingException;
 
 /**
  * @author Gary Russell
@@ -85,7 +84,7 @@ public class SimplePoolTests {
 			pool.getItem();
 			fail("Expected exception");
 		}
-		catch (MessagingException e) { }
+		catch (PoolItemNotAvailableException e) { }
 
 		// resize up
 		pool.setPoolSize(4);
@@ -154,17 +153,20 @@ public class SimplePoolTests {
 			final AtomicBoolean stale) {
 		SimplePool<String> pool = new SimplePool<String>(size, new SimplePool.PoolItemCallback<String>() {
 			private int i;
+			@Override
 			public String createForPool() {
 				String string = "String" + i++;
 				strings.add(string);
 				return string;
 			}
+			@Override
 			public boolean isStale(String item) {
 				if (stale.get()) {
 					strings.remove(item);
 				}
 				return stale.get();
 			}
+			@Override
 			public void removedFromPool(String item) {
 				strings.remove(item);
 			}