RESOLVED - BATCH-1091: Add strict flag to file readers (flat and XML).

added strict flag - when true reader throws exception on open if input resource doesn't exist

spring-batch-infrastructure/src/main/java/org/springframework/batch/item/file/FlatFileItemReader.java

@@ -70,13 +70,25 @@ public class FlatFileItemReader<T> extends AbstractItemCountingItemStreamItemRea
 
 	private LineCallbackHandler skippedLinesCallback;
 
+	private boolean strict = false;
+
 	public FlatFileItemReader() {
 		setName(ClassUtils.getShortName(FlatFileItemReader.class));
 	}
 
 	/**
-	 * @param skippedLinesCallback will be called for each one of the initial skipped
-	 * lines before any items are read.
+	 * In strict mode the reader will throw an exception on
+	 * {@link #open(org.springframework.batch.item.ExecutionContext)} if the
+	 * input resource does not exist.
+	 * @param strict false by default
+	 */
+	public void setStrict(boolean strict) {
+		this.strict = strict;
+	}
+	
+	/**
+	 * @param skippedLinesCallback will be called for each one of the initial
+	 * skipped lines before any items are read.
 	 */
 	public void setSkippedLinesCallback(LineCallbackHandler skippedLinesCallback) {
 		this.skippedLinesCallback = skippedLinesCallback;
@@ -194,7 +206,7 @@ public class FlatFileItemReader<T> extends AbstractItemCountingItemStreamItemRea
 			}
 		}
 		catch (IOException e) {
-			throw new FlatFileParseException("Unable to read from resource: [" + resource + "]", e, line, lineCount );
+			throw new FlatFileParseException("Unable to read from resource: [" + resource + "]", e, line, lineCount);
 		}
 		return line;
 	}
@@ -211,8 +223,7 @@ public class FlatFileItemReader<T> extends AbstractItemCountingItemStreamItemRea
 	@Override
 	protected void doClose() throws Exception {
 		lineCount = 0;
-		if(resource.exists())
-		{
+		if (resource.exists()) {
 			reader.close();
 		}
 	}
@@ -224,6 +235,9 @@ public class FlatFileItemReader<T> extends AbstractItemCountingItemStreamItemRea
 
 		noInput = false;
 		if (!resource.exists()) {
+			if (strict) {
+				throw new IllegalStateException("Input resource must exist (reader is in 'strict' mode)");
+			}
 			noInput = true;
 			logger.warn("Input resource does not exist " + resource.getDescription());
 			return;

spring-batch-infrastructure/src/main/java/org/springframework/batch/item/xml/StaxEventItemReader.java

@@ -69,10 +69,22 @@ public class StaxEventItemReader<T> extends AbstractItemCountingItemStreamItemRe
 
 	private boolean noInput;
 
+	private boolean strict = false;
+	
 	public StaxEventItemReader() {
 		setName(ClassUtils.getShortName(StaxEventItemReader.class));
 	}
 
+	/**
+	 * In strict mode the reader will throw an exception on
+	 * {@link #open(org.springframework.batch.item.ExecutionContext)} if the
+	 * input resource does not exist.
+	 * @param strict false by default
+	 */
+	public void setStrict(boolean strict) {
+		this.strict = strict;
+	}
+
 	public void setResource(Resource resource) {
 		this.resource = resource;
 	}
@@ -162,6 +174,9 @@ public class StaxEventItemReader<T> extends AbstractItemCountingItemStreamItemRe
 		
 		noInput = false;
 		if (!resource.exists()) {
+			if (strict) {
+				throw new IllegalStateException("Input resource must exist (reader is in 'strict' mode)");
+			}
 			noInput = true;
 			logger.warn("Input resource does not exist " + resource.getDescription());
 			return;

spring-batch-infrastructure/src/test/java/org/springframework/batch/item/file/FlatFileItemReaderTests.java

@@ -8,6 +8,7 @@ import java.io.InputStream;
 import org.junit.Before;
 import org.junit.Test;
 import org.springframework.batch.item.ExecutionContext;
+import org.springframework.batch.item.ItemStreamException;
 import org.springframework.batch.item.file.mapping.PassThroughLineMapper;
 import org.springframework.batch.item.file.separator.RecordSeparatorPolicy;
 import org.springframework.core.io.AbstractResource;
@@ -135,6 +136,22 @@ public class FlatFileItemReaderTests {
 		assertEquals(TEST_STRING, reader.read());
 	}
 
+	/**
+	 * In strict mode, resource must exist at the time reader is opened.
+	 */
+	@Test(expected = ItemStreamException.class)
+	public void testStrictness() throws Exception {
+
+		Resource resource = new NonExistentResource();
+
+		reader.setResource(resource);
+		reader.setStrict(true);
+
+		reader.afterPropertiesSet();
+
+		reader.open(executionContext);
+	}
+
 	private Resource getInputResource(String input) {
 		return new ByteArrayResource(input.getBytes());
 	}

spring-batch-infrastructure/src/test/java/org/springframework/batch/item/xml/StaxEventItemReaderTests.java

@@ -231,10 +231,9 @@ public class StaxEventItemReaderTests {
 		source.setResource(new NonExistentResource());
 		source.afterPropertiesSet();
 
-		
 		source.open(executionContext);
 		assertNull(source.read());
-		
+
 	}
 
 	@Test
@@ -248,6 +247,17 @@ public class StaxEventItemReaderTests {
 		source.read();
 	}
 
+	@Test(expected = ItemStreamException.class)
+	public void testStrictness() throws Exception {
+
+		source.setResource(new NonExistentResource());
+		source.setStrict(true);
+		source.afterPropertiesSet();
+
+		source.open(executionContext);
+
+	}
+
 	private StaxEventItemReader<List<XMLEvent>> createNewInputSouce() {
 		Resource resource = new ByteArrayResource(xml.getBytes());