diff --git a/org.springframework.core/src/main/java/org/springframework/core/convert/support/EntityConverter.java b/org.springframework.core/src/main/java/org/springframework/core/convert/support/EntityConverter.java
index 4b96d0cd7d0..c085eb3844b 100644
--- a/org.springframework.core/src/main/java/org/springframework/core/convert/support/EntityConverter.java
+++ b/org.springframework.core/src/main/java/org/springframework/core/convert/support/EntityConverter.java
@@ -18,7 +18,6 @@ package org.springframework.core.convert.support;
 import java.lang.reflect.Method;
 import java.lang.reflect.Modifier;
 
-import org.springframework.core.convert.ConversionService;
 import org.springframework.core.convert.TypeDescriptor;
 import org.springframework.core.convert.converter.ConditionalGenericConverter;
 import org.springframework.util.ClassUtils;
@@ -34,9 +33,9 @@ import org.springframework.util.ReflectionUtils;
  */
 final class EntityConverter implements ConditionalGenericConverter {
 
-	private ConversionService conversionService;
+	private GenericConversionService conversionService;
 
-	public EntityConverter(ConversionService conversionService) {
+	public EntityConverter(GenericConversionService conversionService) {
 		this.conversionService = conversionService;
 	}
 	
@@ -56,6 +55,9 @@ final class EntityConverter implements ConditionalGenericConverter {
 	}
 
 	public Object convert(Object source, TypeDescriptor sourceType, TypeDescriptor targetType) {
+		if (source == null) {
+			return this.conversionService.convertNullSource(sourceType, targetType);
+		}
 		if (String.class.equals(targetType.getType())) {
 			Method idAccessor = getIdAccessor(sourceType.getType());
 			Object id = ReflectionUtils.invokeMethod(idAccessor, source);
diff --git a/org.springframework.core/src/main/java/org/springframework/core/convert/support/StringToBooleanConverter.java b/org.springframework.core/src/main/java/org/springframework/core/convert/support/StringToBooleanConverter.java
index ef91679d18b..36e3090f884 100644
--- a/org.springframework.core/src/main/java/org/springframework/core/convert/support/StringToBooleanConverter.java
+++ b/org.springframework.core/src/main/java/org/springframework/core/convert/support/StringToBooleanConverter.java
@@ -20,7 +20,6 @@ import java.util.HashSet;
 import java.util.Set;
 
 import org.springframework.core.convert.converter.Converter;
-import org.springframework.util.StringUtils;
 
 /**
  * Converts String to a Boolean.
@@ -50,8 +49,8 @@ final class StringToBooleanConverter implements Converter<String, Boolean> {
 	}
 	
 	public Boolean convert(String source) {
-		String value = (source != null ? source.trim() : null);
-		if (!StringUtils.hasLength(value)) {
+		String value = source.trim();
+		if (value.length() == 0) {
 			return null;
 		}
 		else if (trueValues.contains(value)) {
diff --git a/org.springframework.core/src/main/java/org/springframework/core/convert/support/StringToCharacterConverter.java b/org.springframework.core/src/main/java/org/springframework/core/convert/support/StringToCharacterConverter.java
index 7e3525eab7b..3771d83f505 100644
--- a/org.springframework.core/src/main/java/org/springframework/core/convert/support/StringToCharacterConverter.java
+++ b/org.springframework.core/src/main/java/org/springframework/core/convert/support/StringToCharacterConverter.java
@@ -27,7 +27,7 @@ import org.springframework.core.convert.converter.Converter;
 final class StringToCharacterConverter implements Converter<String, Character> {
 
 	public Character convert(String source) {
-		if ("".equals(source)) {
+		if (source.length() == 0) {
 			return null;
 		}
 		if (source.length() > 1) {
diff --git a/org.springframework.core/src/main/java/org/springframework/core/convert/support/StringToEnumConverterFactory.java b/org.springframework.core/src/main/java/org/springframework/core/convert/support/StringToEnumConverterFactory.java
index 181ba2430cf..b3d47d6a511 100644
--- a/org.springframework.core/src/main/java/org/springframework/core/convert/support/StringToEnumConverterFactory.java
+++ b/org.springframework.core/src/main/java/org/springframework/core/convert/support/StringToEnumConverterFactory.java
@@ -41,7 +41,7 @@ final class StringToEnumConverterFactory implements ConverterFactory<String, Enu
 		}
 
 		public T convert(String source) {
-			if ("".equals(source)) {
+			if (source.length() == 0) {
 				// It's an empty enum identifier: reset the enum value to null.
 				return null;
 			}
diff --git a/org.springframework.core/src/main/java/org/springframework/core/convert/support/StringToNumberConverterFactory.java b/org.springframework.core/src/main/java/org/springframework/core/convert/support/StringToNumberConverterFactory.java
index 9b0767cd4e0..8bb0d6460b7 100644
--- a/org.springframework.core/src/main/java/org/springframework/core/convert/support/StringToNumberConverterFactory.java
+++ b/org.springframework.core/src/main/java/org/springframework/core/convert/support/StringToNumberConverterFactory.java
@@ -53,7 +53,7 @@ final class StringToNumberConverterFactory implements ConverterFactory<String, N
 		}
 
 		public T convert(String source) {
-			if ("".equals(source)) {
+			if (source.length() == 0) {
 				return null;
 			}
 			return NumberUtils.parseNumber(source, this.targetType);
diff --git a/org.springframework.core/src/main/java/org/springframework/util/ReflectionUtils.java b/org.springframework.core/src/main/java/org/springframework/util/ReflectionUtils.java
index 170c948f940..7e65495895e 100644
--- a/org.springframework.core/src/main/java/org/springframework/util/ReflectionUtils.java
+++ b/org.springframework.core/src/main/java/org/springframework/util/ReflectionUtils.java
@@ -193,6 +193,9 @@ public abstract class ReflectionUtils {
 	 * @return the invocation result, if any
 	 */
 	public static Object invokeMethod(Method method, Object target, Object... args) {
+		if (target == null) {
+			throw new IllegalArgumentException("target cannot be null");
+		}
 		try {
 			return method.invoke(target, args);
 		}
diff --git a/org.springframework.core/src/test/java/org/springframework/core/convert/support/DefaultConversionTests.java b/org.springframework.core/src/test/java/org/springframework/core/convert/support/DefaultConversionTests.java
index 7f601f11b96..dca76faddd5 100644
--- a/org.springframework.core/src/test/java/org/springframework/core/convert/support/DefaultConversionTests.java
+++ b/org.springframework.core/src/test/java/org/springframework/core/convert/support/DefaultConversionTests.java
@@ -251,6 +251,12 @@ public class DefaultConversionTests {
 		assertEquals(new Long(1), e.getId());
 	}
 
+	@Test
+	public void convertObjectToObjectFinderMethodWithNull() {
+		TestEntity e = (TestEntity) conversionService.convert(null, TypeDescriptor.valueOf(String.class), TypeDescriptor.valueOf(TestEntity.class));
+		assertNull(e);
+	}
+
 	@Test
 	public void convertObjectToObjectFinderMethodWithIdConversion() {
 		TestEntity e = conversionService.convert("1", TestEntity.class);
@@ -263,6 +269,12 @@ public class DefaultConversionTests {
 		assertEquals("1", id);		
 	}
 
+	@Test
+	public void testToObjectToStringIdPropertyWithNull() {
+		String id = (String) conversionService.convert(null, TypeDescriptor.valueOf(TestEntity.class), TypeDescriptor.valueOf(String.class));
+		assertNull(id);	
+	}
+
 	public static class TestEntity {
 
 		private Long id;