BATCH-413: Added a more specific exception type for when an item reader doesn't find any work.

spring-batch-infrastructure/src/main/java/org/springframework/batch/io/driving/DrivingQueryItemReader.java

@@ -21,8 +21,8 @@ import java.util.List;
 import org.springframework.batch.item.ExecutionContext;
 import org.springframework.batch.item.ItemReader;
 import org.springframework.batch.item.ItemStream;
+import org.springframework.batch.item.exception.NoWorkFoundException;
 import org.springframework.beans.factory.InitializingBean;
-import org.springframework.dao.DataRetrievalFailureException;
 import org.springframework.util.Assert;
 
 /**
@@ -141,7 +141,7 @@ public class DrivingQueryItemReader implements ItemReader, InitializingBean,
 				+ ", call close() first.");
 		keys = keyGenerator.retrieveKeys(executionContext);
 		if(keys == null || keys.size() == 0){
-			throw new DataRetrievalFailureException("KeyGenerator must return at least 1 key");
+			throw new NoWorkFoundException("KeyGenerator must return at least 1 key");
 		}
 		keysIterator = keys.listIterator();
 		initialized = true;

spring-batch-infrastructure/src/main/java/org/springframework/batch/item/exception/NoWorkFoundException.java

@@ -0,0 +1,30 @@
+/*
+ * Copyright 2006-2008 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.batch.item.exception;
+
+/**
+ * Exception indicating that an {@link ItemReader} found
+ * no work to process while initializing.
+ * 
+ * @author Lucas Ward
+ *
+ */
+public class NoWorkFoundException extends StreamException {
+
+	public NoWorkFoundException(String msg) {
+		super(msg);
+	}
+}