RESOLVED - issue BATCH-1347: Restartable look-ahead (peekable) ItemReader

2009-11-18 07:45:15 +00:00
parent d67b9d7101
commit c7bb8ae1a8
3 changed files with 339 additions and 0 deletions
--- a/spring-batch-infrastructure/src/test/java/org/springframework/batch/item/support/SingleItemPeekableItemReaderTests.java
+++ b/spring-batch-infrastructure/src/test/java/org/springframework/batch/item/support/SingleItemPeekableItemReaderTests.java
@@ -0,0 +1,135 @@
+/*
+ * Copyright 2006-2010 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.support;
+
+import static org.junit.Assert.assertEquals;
+
+import java.util.Arrays;
+import java.util.List;
+
+import org.junit.Test;
+import org.springframework.batch.item.ExecutionContext;
+
+/**
+ * @author Dave Syer
+ *
+ */
+public class SingleItemPeekableItemReaderTests {
+	
+	private SingleItemPeekableItemReader<String> reader = new SingleItemPeekableItemReader<String>();
+	
+	/**
+	 * Test method for {@link org.springframework.batch.item.support.SingleItemPeekableItemReader#read()}.
+	 */
+	@Test
+	public void testRead() throws Exception {
+		reader.setDelegate(new CountingListItemReader<String>(Arrays.asList("a", "b")));
+		assertEquals("a", reader.read());
+		assertEquals("b", reader.read());
+		assertEquals(null, reader.read());
+	}
+
+	/**
+	 * Test method for {@link org.springframework.batch.item.support.SingleItemPeekableItemReader#peek()}.
+	 */
+	@Test
+	public void testPeek() throws Exception {
+		reader.setDelegate(new CountingListItemReader<String>(Arrays.asList("a", "b")));
+		assertEquals("a", reader.peek());
+		assertEquals("a", reader.read());
+		assertEquals("b", reader.read());
+		assertEquals(null, reader.peek());
+		assertEquals(null, reader.read());
+	}
+
+	/**
+	 * Test method for {@link org.springframework.batch.item.support.SingleItemPeekableItemReader#close()}.
+	 */
+	@Test
+	public void testCloseAndOpenNoPeek() throws Exception {
+		reader.setDelegate(new CountingListItemReader<String>(Arrays.asList("a", "b")));
+		assertEquals("a", reader.read());
+		ExecutionContext executionContext = new ExecutionContext();
+		reader.update(executionContext);
+		reader.close();
+		reader.open(executionContext);
+		assertEquals("b", reader.read());		
+	}
+
+	/**
+	 * Test method for {@link org.springframework.batch.item.support.SingleItemPeekableItemReader#close()}.
+	 */
+	@Test
+	public void testCloseAndOpenWithPeek() throws Exception {
+		reader.setDelegate(new CountingListItemReader<String>(Arrays.asList("a", "b", "c")));
+		assertEquals("a", reader.read());
+		assertEquals("b", reader.peek());
+		ExecutionContext executionContext = new ExecutionContext();
+		reader.update(executionContext);
+		reader.close();
+		reader.open(executionContext);
+		assertEquals("b", reader.read());		
+	}
+
+	@Test
+	public void testCloseAndOpenWithPeekAndRead() throws Exception {
+		ExecutionContext executionContext = new ExecutionContext();
+		reader.setDelegate(new CountingListItemReader<String>(Arrays.asList("a", "b", "c")));
+		assertEquals("a", reader.read());
+		assertEquals("b", reader.peek());
+		reader.update(executionContext);
+		reader.close();
+		reader.open(executionContext);
+		assertEquals("b", reader.read());		
+		assertEquals("c", reader.peek());
+		reader.update(executionContext);
+		reader.close();
+		reader.open(executionContext);
+		assertEquals("c", reader.read());		
+	}
+
+	public static class CountingListItemReader<T> extends AbstractItemCountingItemStreamItemReader<T> {
+		
+		private final List<T> list;
+		
+		private int counter = 0;
+		
+		public CountingListItemReader(List<T> list) {
+			this.list = list;
+			setName("foo");
+		}
+
+		@Override
+		protected void doClose() throws Exception {
+			counter = 0;
+		}
+
+		@Override
+		protected void doOpen() throws Exception {
+			counter = 0;
+		}
+
+		@Override
+		protected T doRead() throws Exception {
+			if (counter>=list.size()) {
+				return null;
+			}
+			return list.get(counter++);
+		}
+		
+	}
+
+}