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Use ResolvableType in GenericCollectnTypeResolver

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Refactor GenericCollectionTypeResolver to make use of ResolvableType
for generic resolution.

Issue: SPR-10977
This commit is contained in:
Phillip Webb
2013-10-09 18:42:30 -07:00
parent 595efe9aab
commit fdf0ef40c0
1 changed files with 33 additions and 238 deletions
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271
spring-core/src/main/java/org/springframework/core/GenericCollectionTypeResolver.java
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@@ -16,15 +16,8 @@
package org.springframework.core;
import java.lang.reflect.Array;
import java.lang.reflect.Field;
import java.lang.reflect.GenericArrayType;
import java.lang.reflect.MalformedParameterizedTypeException;
import java.lang.reflect.Method;
import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type;
import java.lang.reflect.TypeVariable;
import java.lang.reflect.WildcardType;
import java.util.Collection;
import java.util.Map;
@@ -36,7 +29,9 @@ import java.util.Map;
* (to be able to attempt type conversion if appropriate).
*
* @author Juergen Hoeller
* @author Phillip Webb
* @since 2.0
* @see ResolvableType
*/
public abstract class GenericCollectionTypeResolver {
@@ -47,7 +42,7 @@ public abstract class GenericCollectionTypeResolver {
* @return the generic type, or {@code null} if none
*/
public static Class<?> getCollectionType(Class<? extends Collection> collectionClass) {
return extractTypeFromClass(collectionClass, Collection.class, 0);
return ResolvableType.forClass(collectionClass).asCollection().resolveGeneric();
}
/**
@@ -57,7 +52,7 @@ public abstract class GenericCollectionTypeResolver {
* @return the generic type, or {@code null} if none
*/
public static Class<?> getMapKeyType(Class<? extends Map> mapClass) {
return extractTypeFromClass(mapClass, Map.class, 0);
return ResolvableType.forClass(mapClass).asMap().resolveGeneric(0);
}
/**
@@ -67,7 +62,7 @@ public abstract class GenericCollectionTypeResolver {
* @return the generic type, or {@code null} if none
*/
public static Class<?> getMapValueType(Class<? extends Map> mapClass) {
return extractTypeFromClass(mapClass, Map.class, 1);
return ResolvableType.forClass(mapClass).asMap().resolveGeneric(1);
}
/**
@@ -76,7 +71,7 @@ public abstract class GenericCollectionTypeResolver {
* @return the generic type, or {@code null} if none
*/
public static Class<?> getCollectionFieldType(Field collectionField) {
return getGenericFieldType(collectionField, Collection.class, 0, null, 1);
return ResolvableType.forField(collectionField).asCollection().resolveGeneric();
}
/**
@@ -88,7 +83,7 @@ public abstract class GenericCollectionTypeResolver {
* @return the generic type, or {@code null} if none
*/
public static Class<?> getCollectionFieldType(Field collectionField, int nestingLevel) {
return getGenericFieldType(collectionField, Collection.class, 0, null, nestingLevel);
return ResolvableType.forField(collectionField).getNested(nestingLevel).asCollection().resolveGeneric();
}
/**
@@ -100,9 +95,11 @@ public abstract class GenericCollectionTypeResolver {
* @param typeIndexesPerLevel Map keyed by nesting level, with each value
* expressing the type index for traversal at that level
* @return the generic type, or {@code null} if none
* @deprecated as of 4.0 in favor of using {@link ResolvableType} for arbitrary nesting levels
*/
@Deprecated
public static Class<?> getCollectionFieldType(Field collectionField, int nestingLevel, Map<Integer, Integer> typeIndexesPerLevel) {
return getGenericFieldType(collectionField, Collection.class, 0, typeIndexesPerLevel, nestingLevel);
return ResolvableType.forField(collectionField).getNested(nestingLevel, typeIndexesPerLevel).asCollection().resolveGeneric();
}
/**
@@ -111,7 +108,7 @@ public abstract class GenericCollectionTypeResolver {
* @return the generic type, or {@code null} if none
*/
public static Class<?> getMapKeyFieldType(Field mapField) {
return getGenericFieldType(mapField, Map.class, 0, null, 1);
return ResolvableType.forField(mapField).asMap().resolveGeneric(0);
}
/**
@@ -123,7 +120,7 @@ public abstract class GenericCollectionTypeResolver {
* @return the generic type, or {@code null} if none
*/
public static Class<?> getMapKeyFieldType(Field mapField, int nestingLevel) {
return getGenericFieldType(mapField, Map.class, 0, null, nestingLevel);
return ResolvableType.forField(mapField).getNested(nestingLevel).asMap().resolveGeneric(0);
}
/**
@@ -135,9 +132,11 @@ public abstract class GenericCollectionTypeResolver {
* @param typeIndexesPerLevel Map keyed by nesting level, with each value
* expressing the type index for traversal at that level
* @return the generic type, or {@code null} if none
* @deprecated as of 4.0 in favor of using {@link ResolvableType} for arbitrary nesting levels
*/
@Deprecated
public static Class<?> getMapKeyFieldType(Field mapField, int nestingLevel, Map<Integer, Integer> typeIndexesPerLevel) {
return getGenericFieldType(mapField, Map.class, 0, typeIndexesPerLevel, nestingLevel);
return ResolvableType.forField(mapField).getNested(nestingLevel, typeIndexesPerLevel).asMap().resolveGeneric(0);
}
/**
@@ -146,7 +145,7 @@ public abstract class GenericCollectionTypeResolver {
* @return the generic type, or {@code null} if none
*/
public static Class<?> getMapValueFieldType(Field mapField) {
return getGenericFieldType(mapField, Map.class, 1, null, 1);
return ResolvableType.forField(mapField).asMap().resolveGeneric(1);
}
/**
@@ -158,7 +157,7 @@ public abstract class GenericCollectionTypeResolver {
* @return the generic type, or {@code null} if none
*/
public static Class<?> getMapValueFieldType(Field mapField, int nestingLevel) {
return getGenericFieldType(mapField, Map.class, 1, null, nestingLevel);
return ResolvableType.forField(mapField).getNested(nestingLevel).asMap().resolveGeneric(1);
}
/**
@@ -170,9 +169,11 @@ public abstract class GenericCollectionTypeResolver {
* @param typeIndexesPerLevel Map keyed by nesting level, with each value
* expressing the type index for traversal at that level
* @return the generic type, or {@code null} if none
* @deprecated as of 4.0 in favor of using {@link ResolvableType} for arbitrary nesting levels
*/
@Deprecated
public static Class<?> getMapValueFieldType(Field mapField, int nestingLevel, Map<Integer, Integer> typeIndexesPerLevel) {
return getGenericFieldType(mapField, Map.class, 1, typeIndexesPerLevel, nestingLevel);
return ResolvableType.forField(mapField).getNested(nestingLevel, typeIndexesPerLevel).asMap().resolveGeneric(1);
}
/**
@@ -181,7 +182,7 @@ public abstract class GenericCollectionTypeResolver {
* @return the generic type, or {@code null} if none
*/
public static Class<?> getCollectionParameterType(MethodParameter methodParam) {
return getGenericParameterType(methodParam, Collection.class, 0);
return forMethodParameter(methodParam).asCollection().resolveGeneric();
}
/**
@@ -190,7 +191,7 @@ public abstract class GenericCollectionTypeResolver {
* @return the generic type, or {@code null} if none
*/
public static Class<?> getMapKeyParameterType(MethodParameter methodParam) {
return getGenericParameterType(methodParam, Map.class, 0);
return forMethodParameter(methodParam).asMap().resolveGeneric(0);
}
/**
@@ -199,7 +200,7 @@ public abstract class GenericCollectionTypeResolver {
* @return the generic type, or {@code null} if none
*/
public static Class<?> getMapValueParameterType(MethodParameter methodParam) {
return getGenericParameterType(methodParam, Map.class, 1);
return forMethodParameter(methodParam).asMap().resolveGeneric(1);
}
/**
@@ -208,7 +209,7 @@ public abstract class GenericCollectionTypeResolver {
* @return the generic type, or {@code null} if none
*/
public static Class<?> getCollectionReturnType(Method method) {
return getGenericReturnType(method, Collection.class, 0, 1);
return ResolvableType.forMethodReturn(method).asCollection().resolveGeneric();
}
/**
@@ -222,7 +223,7 @@ public abstract class GenericCollectionTypeResolver {
* @return the generic type, or {@code null} if none
*/
public static Class<?> getCollectionReturnType(Method method, int nestingLevel) {
return getGenericReturnType(method, Collection.class, 0, nestingLevel);
return ResolvableType.forMethodReturn(method).getNested(nestingLevel).asCollection().resolveGeneric();
}
/**
@@ -231,7 +232,7 @@ public abstract class GenericCollectionTypeResolver {
* @return the generic type, or {@code null} if none
*/
public static Class<?> getMapKeyReturnType(Method method) {
return getGenericReturnType(method, Map.class, 0, 1);
return ResolvableType.forMethodReturn(method).asMap().resolveGeneric(0);
}
/**
@@ -243,7 +244,7 @@ public abstract class GenericCollectionTypeResolver {
* @return the generic type, or {@code null} if none
*/
public static Class<?> getMapKeyReturnType(Method method, int nestingLevel) {
return getGenericReturnType(method, Map.class, 0, nestingLevel);
return ResolvableType.forMethodReturn(method).getNested(nestingLevel).asMap().resolveGeneric(0);
}
/**
@@ -252,7 +253,7 @@ public abstract class GenericCollectionTypeResolver {
* @return the generic type, or {@code null} if none
*/
public static Class<?> getMapValueReturnType(Method method) {
return getGenericReturnType(method, Map.class, 1, 1);
return ResolvableType.forMethodReturn(method).asMap().resolveGeneric(1);
}
/**
@@ -264,220 +265,14 @@ public abstract class GenericCollectionTypeResolver {
* @return the generic type, or {@code null} if none
*/
public static Class<?> getMapValueReturnType(Method method, int nestingLevel) {
return getGenericReturnType(method, Map.class, 1, nestingLevel);
return ResolvableType.forMethodReturn(method).getNested(nestingLevel).asMap().resolveGeneric(1);
}
/**
* Extract the generic parameter type from the given method or constructor.
* @param methodParam the method parameter specification
* @param source the source class/interface defining the generic parameter types
* @param typeIndex the index of the type (e.g. 0 for Collections,
* 0 for Map keys, 1 for Map values)
* @return the generic type, or {@code null} if none
*/
private static Class<?> getGenericParameterType(MethodParameter methodParam, Class<?> source, int typeIndex) {
return extractType(GenericTypeResolver.getTargetType(methodParam), source, typeIndex,
methodParam.typeVariableMap, methodParam.typeIndexesPerLevel, methodParam.getNestingLevel(), 1);
}
/**
* Extract the generic type from the given field.
* @param field the field to check the type for
* @param source the source class/interface defining the generic parameter types
* @param typeIndex the index of the type (e.g. 0 for Collections,
* 0 for Map keys, 1 for Map values)
* @param nestingLevel the nesting level of the target type
* @return the generic type, or {@code null} if none
*/
private static Class<?> getGenericFieldType(Field field, Class<?> source, int typeIndex,
Map<Integer, Integer> typeIndexesPerLevel, int nestingLevel) {
return extractType(field.getGenericType(), source, typeIndex, null, typeIndexesPerLevel, nestingLevel, 1);
}
/**
* Extract the generic return type from the given method.
* @param method the method to check the return type for
* @param source the source class/interface defining the generic parameter types
* @param typeIndex the index of the type (e.g. 0 for Collections,
* 0 for Map keys, 1 for Map values)
* @param nestingLevel the nesting level of the target type
* @return the generic type, or {@code null} if none
*/
private static Class<?> getGenericReturnType(Method method, Class<?> source, int typeIndex, int nestingLevel) {
return extractType(method.getGenericReturnType(), source, typeIndex, null, null, nestingLevel, 1);
}
/**
* Extract the generic type from the given Type object.
* @param type the Type to check
* @param source the source collection/map Class that we check
* @param typeIndex the index of the actual type argument
* @param nestingLevel the nesting level of the target type
* @param currentLevel the current nested level
* @return the generic type as Class, or {@code null} if none
*/
private static Class<?> extractType(Type type, Class<?> source, int typeIndex,
Map<TypeVariable, Type> typeVariableMap, Map<Integer, Integer> typeIndexesPerLevel,
int nestingLevel, int currentLevel) {
Type resolvedType = type;
if (type instanceof TypeVariable && typeVariableMap != null) {
Type mappedType = typeVariableMap.get(type);
if (mappedType != null) {
resolvedType = mappedType;
}
private static ResolvableType forMethodParameter(MethodParameter methodParam) {
if (methodParam.resolveClass != null) {
return ResolvableType.forMethodParameter(methodParam, methodParam.resolveClass);
}
if (resolvedType instanceof ParameterizedType) {
return extractTypeFromParameterizedType((ParameterizedType) resolvedType, source, typeIndex, typeVariableMap, typeIndexesPerLevel,
nestingLevel, currentLevel);
}
else if (resolvedType instanceof Class) {
return extractTypeFromClass((Class) resolvedType, source, typeIndex, typeVariableMap, typeIndexesPerLevel,
nestingLevel, currentLevel);
}
else if (resolvedType instanceof GenericArrayType) {
Type compType = ((GenericArrayType) resolvedType).getGenericComponentType();
return extractType(compType, source, typeIndex, typeVariableMap, typeIndexesPerLevel, nestingLevel, currentLevel + 1);
}
else {
return null;
}
}
/**
* Extract the generic type from the given ParameterizedType object.
* @param ptype the ParameterizedType to check
* @param source the expected raw source type (can be {@code null})
* @param typeIndex the index of the actual type argument
* @param nestingLevel the nesting level of the target type
* @param currentLevel the current nested level
* @return the generic type as Class, or {@code null} if none
*/
private static Class<?> extractTypeFromParameterizedType(ParameterizedType ptype, Class<?> source, int typeIndex,
Map<TypeVariable, Type> typeVariableMap, Map<Integer, Integer> typeIndexesPerLevel,
int nestingLevel, int currentLevel) {
if (!(ptype.getRawType() instanceof Class)) {
return null;
}
Class rawType = (Class) ptype.getRawType();
Type[] paramTypes = ptype.getActualTypeArguments();
if (nestingLevel - currentLevel > 0) {
int nextLevel = currentLevel + 1;
Integer currentTypeIndex = (typeIndexesPerLevel != null ? typeIndexesPerLevel.get(nextLevel) : null);
// Default is last parameter type: Collection element or Map value.
int indexToUse = (currentTypeIndex != null ? currentTypeIndex : paramTypes.length - 1);
Type paramType = paramTypes[indexToUse];
return extractType(paramType, source, typeIndex, typeVariableMap, typeIndexesPerLevel, nestingLevel, nextLevel);
}
if (source != null && !source.isAssignableFrom(rawType)) {
return null;
}
Class fromSuperclassOrInterface = extractTypeFromClass(rawType, source, typeIndex, typeVariableMap, typeIndexesPerLevel,
nestingLevel, currentLevel);
if (fromSuperclassOrInterface != null) {
return fromSuperclassOrInterface;
}
if (paramTypes == null || typeIndex >= paramTypes.length) {
return null;
}
Type paramType = paramTypes[typeIndex];
if (paramType instanceof TypeVariable && typeVariableMap != null) {
Type mappedType = typeVariableMap.get(paramType);
if (mappedType != null) {
paramType = mappedType;
}
}
if (paramType instanceof WildcardType) {
WildcardType wildcardType = (WildcardType) paramType;
Type[] upperBounds = wildcardType.getUpperBounds();
if (upperBounds != null && upperBounds.length > 0 && !Object.class.equals(upperBounds[0])) {
paramType = upperBounds[0];
}
else {
Type[] lowerBounds = wildcardType.getLowerBounds();
if (lowerBounds != null && lowerBounds.length > 0 && !Object.class.equals(lowerBounds[0])) {
paramType = lowerBounds[0];
}
}
}
if (paramType instanceof ParameterizedType) {
paramType = ((ParameterizedType) paramType).getRawType();
}
if (paramType instanceof GenericArrayType) {
// A generic array type... Let's turn it into a straight array type if possible.
Type compType = ((GenericArrayType) paramType).getGenericComponentType();
if (compType instanceof Class) {
return Array.newInstance((Class) compType, 0).getClass();
}
}
else if (paramType instanceof Class) {
// We finally got a straight Class...
return (Class) paramType;
}
return null;
}
/**
* Extract the generic type from the given Class object.
* @param clazz the Class to check
* @param source the expected raw source type (can be {@code null})
* @param typeIndex the index of the actual type argument
* @return the generic type as Class, or {@code null} if none
*/
private static Class<?> extractTypeFromClass(Class<?> clazz, Class<?> source, int typeIndex) {
return extractTypeFromClass(clazz, source, typeIndex, null, null, 1, 1);
}
/**
* Extract the generic type from the given Class object.
* @param clazz the Class to check
* @param source the expected raw source type (can be {@code null})
* @param typeIndex the index of the actual type argument
* @param nestingLevel the nesting level of the target type
* @param currentLevel the current nested level
* @return the generic type as Class, or {@code null} if none
*/
private static Class<?> extractTypeFromClass(Class<?> clazz, Class<?> source, int typeIndex,
Map<TypeVariable, Type> typeVariableMap, Map<Integer, Integer> typeIndexesPerLevel,
int nestingLevel, int currentLevel) {
if (clazz.getName().startsWith("java.util.")) {
return null;
}
if (clazz.getSuperclass() != null && isIntrospectionCandidate(clazz.getSuperclass())) {
try {
return extractType(clazz.getGenericSuperclass(), source, typeIndex, typeVariableMap,
typeIndexesPerLevel, nestingLevel, currentLevel);
}
catch (MalformedParameterizedTypeException ex) {
// from getGenericSuperclass() - ignore and continue with interface introspection
}
}
Type[] ifcs = clazz.getGenericInterfaces();
if (ifcs != null) {
for (Type ifc : ifcs) {
Type rawType = ifc;
if (ifc instanceof ParameterizedType) {
rawType = ((ParameterizedType) ifc).getRawType();
}
if (rawType instanceof Class && isIntrospectionCandidate((Class) rawType)) {
return extractType(ifc, source, typeIndex, typeVariableMap, typeIndexesPerLevel, nestingLevel, currentLevel);
}
}
}
return null;
}
/**
* Determine whether the given class is a potential candidate
* that defines generic collection or map types.
* @param clazz the class to check
* @return whether the given class is assignable to Collection or Map
*/
private static boolean isIntrospectionCandidate(Class clazz) {
return (Collection.class.isAssignableFrom(clazz) || Map.class.isAssignableFrom(clazz));
return ResolvableType.forMethodParameter(methodParam);
}
}