From cb17024c01fb71b94feae5c0b617a005eb494ca6 Mon Sep 17 00:00:00 2001
From: dsyer <dsyer@2e8e966d-6415-0410-94b9-dc4e65435d03>
Date: Wed, 9 Dec 2009 13:09:02 +0000
Subject: [PATCH] RESOLVED - issue BATCH-924: BeanWrapperFieldSetMapper could
 create child objects if they are null when needed

---
 .../mapping/BeanWrapperFieldSetMapper.java    | 24 ++++++++++++++-
 .../BeanWrapperFieldSetMapperTests.java       | 29 ++++++++++++++-----
 2 files changed, 45 insertions(+), 8 deletions(-)

diff --git a/spring-batch-infrastructure/src/main/java/org/springframework/batch/item/file/mapping/BeanWrapperFieldSetMapper.java b/spring-batch-infrastructure/src/main/java/org/springframework/batch/item/file/mapping/BeanWrapperFieldSetMapper.java
index cb90b25e8..6a845778e 100644
--- a/spring-batch-infrastructure/src/main/java/org/springframework/batch/item/file/mapping/BeanWrapperFieldSetMapper.java
+++ b/spring-batch-infrastructure/src/main/java/org/springframework/batch/item/file/mapping/BeanWrapperFieldSetMapper.java
@@ -264,6 +264,10 @@ public class BeanWrapperFieldSetMapper<T> extends DefaultPropertyEditorRegistrar
 
 	private String findPropertyName(Object bean, String key) {
 
+		if (bean == null) {
+			return null;
+		}
+
 		Class<?> cls = bean.getClass();
 
 		int index = PropertyAccessorUtils.getFirstNestedPropertySeparatorIndex(key);
@@ -280,7 +284,7 @@ public class BeanWrapperFieldSetMapper<T> extends DefaultPropertyEditorRegistrar
 				return null;
 			}
 
-			Object nestedValue = new BeanWrapperImpl(bean).getPropertyValue(nestedName);
+			Object nestedValue = getPropertyValue(bean, nestedName);
 			String nestedPropertyName = findPropertyName(nestedValue, suffix);
 			return nestedPropertyName == null ? null : nestedName + "." + nestedPropertyName;
 		}
@@ -316,6 +320,24 @@ public class BeanWrapperFieldSetMapper<T> extends DefaultPropertyEditorRegistrar
 		return name;
 	}
 
+	private Object getPropertyValue(Object bean, String nestedName) {
+		BeanWrapperImpl wrapper = new BeanWrapperImpl(bean);
+		Object nestedValue = wrapper.getPropertyValue(nestedName);
+		if (nestedValue == null) {
+			try {
+				nestedValue = wrapper.getPropertyType(nestedName).newInstance();
+				wrapper.setPropertyValue(nestedName, nestedValue);
+			}
+			catch (InstantiationException e) {
+				ReflectionUtils.handleReflectionException(e);
+			}
+			catch (IllegalAccessException e) {
+				ReflectionUtils.handleReflectionException(e);
+			}
+		}
+		return nestedValue;
+	}
+
 	private void switchPropertyNames(Properties properties, String oldName, String newName) {
 		String value = properties.getProperty(oldName);
 		properties.remove(oldName);
diff --git a/spring-batch-infrastructure/src/test/java/org/springframework/batch/item/file/mapping/BeanWrapperFieldSetMapperTests.java b/spring-batch-infrastructure/src/test/java/org/springframework/batch/item/file/mapping/BeanWrapperFieldSetMapperTests.java
index 29bcf614c..707dddf72 100644
--- a/spring-batch-infrastructure/src/test/java/org/springframework/batch/item/file/mapping/BeanWrapperFieldSetMapperTests.java
+++ b/spring-batch-infrastructure/src/test/java/org/springframework/batch/item/file/mapping/BeanWrapperFieldSetMapperTests.java
@@ -86,6 +86,18 @@ public class BeanWrapperFieldSetMapperTests {
 		assertEquals('C', result.getVarChar());
 	}
 
+	@Test
+	public void testNullPropertyAutoCreated() throws Exception {
+		BeanWrapperFieldSetMapper<TestNestedA> mapper = new BeanWrapperFieldSetMapper<TestNestedA>();
+		mapper.setTargetType(TestNestedA.class);
+		mapper.afterPropertiesSet();
+
+		FieldSet fieldSet = new DefaultFieldSet(new String[] { "Foo", "Bar" }, new String[] { "valueA",
+				"testObjectB.valueA" });
+		TestNestedA result = mapper.mapFieldSet(fieldSet);
+		assertEquals("Bar", result.getTestObjectB().getValueA());
+	}
+
 	@Test
 	public void testMapperWithSingleton() throws Exception {
 		BeanWrapperFieldSetMapper<TestObject> mapper = new BeanWrapperFieldSetMapper<TestObject>();
@@ -377,11 +389,13 @@ public class BeanWrapperFieldSetMapperTests {
 		BeanWrapperFieldSetMapper<TestObject> mapper = new BeanWrapperFieldSetMapper<TestObject>();
 		mapper.setTargetType(TestObject.class);
 
-		FieldSet fieldSet = new DefaultFieldSet(new String[] { "foo", "7890.1" }, new String[] { "varDouble", "varFloat" });
+		FieldSet fieldSet = new DefaultFieldSet(new String[] { "foo", "7890.1" }, new String[] { "varDouble",
+				"varFloat" });
 		try {
 			mapper.mapFieldSet(fieldSet);
 			fail("Expected BindException");
-		} catch (BindException e) {
+		}
+		catch (BindException e) {
 			assertEquals(1, e.getErrorCount());
 			assertEquals("typeMismatch", e.getFieldError("varDouble").getCode());
 		}
@@ -474,7 +488,7 @@ public class BeanWrapperFieldSetMapperTests {
 
 	}
 
-	private static class TestNestedA {
+	public static class TestNestedA {
 		private String valueA;
 
 		private int valueB;
@@ -507,7 +521,7 @@ public class BeanWrapperFieldSetMapperTests {
 
 	}
 
-	private static class TestNestedB {
+	public static class TestNestedB {
 		private String valueA;
 
 		private TestNestedC testObjectC;
@@ -530,6 +544,7 @@ public class BeanWrapperFieldSetMapperTests {
 
 	}
 
+	@SuppressWarnings("unused")
 	private static class TestNestedC {
 		private int value;
 
@@ -564,7 +579,7 @@ public class BeanWrapperFieldSetMapperTests {
 		}
 
 	}
-	
+
 	public static class TestObject {
 		String varString;
 
@@ -589,11 +604,11 @@ public class BeanWrapperFieldSetMapperTests {
 		Date varDate;
 
 		public Date getVarDate() {
-			return (Date)varDate.clone();
+			return (Date) varDate.clone();
 		}
 
 		public void setVarDate(Date varDate) {
-			this.varDate = varDate == null ? null : (Date)varDate.clone();
+			this.varDate = varDate == null ? null : (Date) varDate.clone();
 		}
 
 		public TestObject() {