RESOLVED - BATCH-589: StepExecutionResourceProxy's toString() leads to NPE

toString returns filePattern if delegate is null

spring-batch-core/src/main/java/org/springframework/batch/core/resource/StepExecutionResourceProxy.java

@@ -288,12 +288,10 @@ public class StepExecutionResourceProxy extends StepExecutionListenerSupport imp
 	}
 
 	/**
-	 * Delegates to the proxied Resource.
+	 * Delegates to the proxied Resource if set, otherwise returns the {@link #filePattern}.
 	 */
 	public String toString() {
-		Assert.state(delegate != null, "The delegate resource has not been initialised. "
-				+ "Remember to register this object as a StepListener.");
-		return delegate.toString();
+		return (delegate == null) ? filePattern : delegate.toString(); 
 	}
 
 }

spring-batch-core/src/test/java/org/springframework/batch/core/resource/StepExecutionResourceProxyTests.java

@@ -133,6 +133,16 @@ public class StepExecutionResourceProxyTests extends TestCase {
 		resource.beforeStep(stepExecution);
 		assertEquals("to-string-test-resource", resource.toString());
 	}
+	
+	/**
+	 * If delegate is not set toString returns the filePattern.
+	 */
+	public void testToStringWithNullDelegate() {
+		resource = new StepExecutionResourceProxy();
+		String filePattern = "arbitrary pattern";
+		resource.setFilePattern("arbitrary pattern");
+		assertEquals(filePattern, resource.toString());
+	}
 
 	private void doTestPathName(String filename, String path) throws Exception, IOException {
 		String returnedPath = resource.getFile().getAbsolutePath();