Class identity comparisons wherever possible

Issue: SPR-12926

Author: jhoeller

spring-context/src/main/java/org/springframework/format/support/FormattingConversionService.java

@@ -226,6 +226,7 @@ private class AnnotationPrinterConverter implements ConditionalGenericConverter
 
 		public AnnotationPrinterConverter(Class<? extends Annotation> annotationType,
 				AnnotationFormatterFactory<?> annotationFormatterFactory, Class<?> fieldType) {
+
 			this.annotationType = annotationType;
 			this.annotationFormatterFactory = annotationFormatterFactory;
 			this.fieldType = fieldType;
@@ -279,6 +280,7 @@ private class AnnotationParserConverter implements ConditionalGenericConverter {
 
 		public AnnotationParserConverter(Class<? extends Annotation> annotationType,
 				AnnotationFormatterFactory<?> annotationFormatterFactory, Class<?> fieldType) {
+
 			this.annotationType = annotationType;
 			this.annotationFormatterFactory = annotationFormatterFactory;
 			this.fieldType = fieldType;
@@ -345,16 +347,13 @@ public boolean equals(Object other) {
 			if (this == other) {
 				return true;
 			}
-			if (!(other instanceof AnnotationConverterKey)) {
-				return false;
-			}
 			AnnotationConverterKey otherKey = (AnnotationConverterKey) other;
-			return (this.annotation.equals(otherKey.annotation) && this.fieldType.equals(otherKey.fieldType));
+			return (this.fieldType == otherKey.fieldType && this.annotation.equals(otherKey.annotation));
 		}
 
 		@Override
 		public int hashCode() {
-			return (this.annotation.hashCode() + 29 * this.fieldType.hashCode());
+			return (this.fieldType.hashCode() * 29 + this.annotation.hashCode());
 		}
 	}
 

spring-core/src/main/java/org/springframework/core/convert/TypeDescriptor.java

@@ -80,7 +80,6 @@ public class TypeDescriptor implements Serializable {
 	 * @param methodParameter the method parameter
 	 */
 	public TypeDescriptor(MethodParameter methodParameter) {
-		Assert.notNull(methodParameter, "MethodParameter must not be null");
 		this.resolvableType = ResolvableType.forMethodParameter(methodParameter);
 		this.type = this.resolvableType.resolve(methodParameter.getParameterType());
 		this.annotations = nullSafeAnnotations(methodParameter.getParameterIndex() == -1 ?
@@ -93,7 +92,6 @@ public TypeDescriptor(MethodParameter methodParameter) {
 	 * @param field the field
 	 */
 	public TypeDescriptor(Field field) {
-		Assert.notNull(field, "Field must not be null");
 		this.resolvableType = ResolvableType.forField(field);
 		this.type = this.resolvableType.resolve(field.getType());
 		this.annotations = nullSafeAnnotations(field.getAnnotations());
@@ -451,31 +449,31 @@ private TypeDescriptor narrow(Object value, TypeDescriptor typeDescriptor) {
 	}
 
 	@Override
-	public boolean equals(Object obj) {
-		if (this == obj) {
+	public boolean equals(Object other) {
+		if (this == other) {
 			return true;
 		}
-		if (!(obj instanceof TypeDescriptor)) {
+		if (!(other instanceof TypeDescriptor)) {
 			return false;
 		}
-		TypeDescriptor other = (TypeDescriptor) obj;
-		if (!ObjectUtils.nullSafeEquals(this.type, other.type)) {
+		TypeDescriptor otherDesc = (TypeDescriptor) other;
+		if (getType() != otherDesc.getType()) {
 			return false;
 		}
-		if (getAnnotations().length != other.getAnnotations().length) {
+		if (getAnnotations().length != otherDesc.getAnnotations().length) {
 			return false;
 		}
 		for (Annotation ann : getAnnotations()) {
-			if (!other.hasAnnotation(ann.annotationType())) {
+			if (!otherDesc.hasAnnotation(ann.annotationType())) {
 				return false;
 			}
 		}
 		if (isCollection() || isArray()) {
-			return ObjectUtils.nullSafeEquals(getElementTypeDescriptor(), other.getElementTypeDescriptor());
+			return ObjectUtils.nullSafeEquals(getElementTypeDescriptor(), otherDesc.getElementTypeDescriptor());
 		}
 		else if (isMap()) {
-			return ObjectUtils.nullSafeEquals(getMapKeyTypeDescriptor(), other.getMapKeyTypeDescriptor()) &&
-					ObjectUtils.nullSafeEquals(getMapValueTypeDescriptor(), other.getMapValueTypeDescriptor());
+			return (ObjectUtils.nullSafeEquals(getMapKeyTypeDescriptor(), otherDesc.getMapKeyTypeDescriptor()) &&
+					ObjectUtils.nullSafeEquals(getMapValueTypeDescriptor(), otherDesc.getMapValueTypeDescriptor()));
 		}
 		else {
 			return true;