DATAMONGO-813 - Improve handling for non-existing resources in GridFSTemplate.

We now return null for a non-existing resource instead of throwing a NPE.

Original pull request: #106.

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/gridfs/GridFsOperations.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2011-2012 the original author or authors.
+ * Copyright 2011-2013 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.
@@ -31,6 +31,7 @@ import com.mongodb.gridfs.GridFSFile;
  * 
  * @author Oliver Gierke
  * @author Philipp Schneider
+ * @author Thomas Darimont
  */
 public interface GridFsOperations extends ResourcePatternResolver {
 
@@ -126,7 +127,7 @@ public interface GridFsOperations extends ResourcePatternResolver {
 	 * Returns all {@link GridFsResource} with the given file name.
 	 * 
 	 * @param filename
-	 * @return
+	 * @return the resource if it exists or {@literal null}.
 	 * @see ResourcePatternResolver#getResource(String)
 	 */
 	GridFsResource getResource(String filename);

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/gridfs/GridFsTemplate.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2011-2012 the original author or authors.
+ * Copyright 2011-2013 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.
@@ -43,6 +43,7 @@ import com.mongodb.gridfs.GridFSInputFile;
  * 
  * @author Oliver Gierke
  * @author Philipp Schneider
+ * @author Thomas Darimont
  */
 public class GridFsTemplate implements GridFsOperations, ResourcePatternResolver {
 
@@ -198,7 +199,9 @@ public class GridFsTemplate implements GridFsOperations, ResourcePatternResolver
 	 * @see org.springframework.core.io.ResourceLoader#getResource(java.lang.String)
 	 */
 	public GridFsResource getResource(String location) {
-		return new GridFsResource(findOne(query(whereFilename().is(location))));
+
+		GridFSDBFile file = findOne(query(whereFilename().is(location)));
+		return file != null ? new GridFsResource(file) : null;
 	}
 
 	/*

spring-data-mongodb/src/test/java/org/springframework/data/mongodb/gridfs/GridFsTemplateIntegrationTests.java

@@ -45,10 +45,11 @@ import com.mongodb.gridfs.GridFSFile;
  * 
  * @author Oliver Gierke
  * @author Philipp Schneider
+ * @author Thomas Darimont
  */
 @RunWith(SpringJUnit4ClassRunner.class)
 @ContextConfiguration("classpath:gridfs/gridfs.xml")
-public class GridFsTemplateIIntegrationTests {
+public class GridFsTemplateIntegrationTests {
 
 	Resource resource = new ClassPathResource("gridfs/gridfs.xml");
 
@@ -162,6 +163,14 @@ public class GridFsTemplateIIntegrationTests {
 		assertSame(result.get(0), reference);
 	}
 
+	/**
+	 * @see DATAMONGO-813
+	 */
+	@Test
+	public void getResourceShouldReturnNullForNonExistingResource() {
+		assertThat(operations.getResource("doesnotexist"), is(nullValue()));
+	}
+
 	private static void assertSame(GridFSFile left, GridFSFile right) {
 
 		assertThat(left.getId(), is(right.getId()));