org.springframework.core

Class GenericCollectionTypeResolver

java.lang.Object

org.springframework.core.GenericCollectionTypeResolver

public abstract class GenericCollectionTypeResolver
extends java.lang.Object

Helper class for determining element types of collections and maps.

Mainly intended for usage within the framework, determining the target type of values to be added to a collection or map (to be able to attempt type conversion if appropriate).

Since:

2.0

Author:

Juergen Hoeller, Phillip Webb

See Also:

ResolvableType

Constructor Summary

Constructors

Constructor and Description
GenericCollectionTypeResolver()

Method Summary

Modifier and Type	Method and Description
static java.lang.Class<?>	getCollectionFieldType(java.lang.reflect.Field collectionField) Determine the generic element type of the given Collection field.
static java.lang.Class<?>	getCollectionFieldType(java.lang.reflect.Field collectionField, int nestingLevel) Determine the generic element type of the given Collection field.
static java.lang.Class<?>	getCollectionFieldType(java.lang.reflect.Field collectionField, int nestingLevel, java.util.Map<java.lang.Integer,java.lang.Integer> typeIndexesPerLevel) Deprecated. as of 4.0, in favor of using ResolvableType for arbitrary nesting levels
static java.lang.Class<?>	getCollectionParameterType(MethodParameter methodParam) Determine the generic element type of the given Collection parameter.
static java.lang.Class<?>	getCollectionReturnType(java.lang.reflect.Method method) Determine the generic element type of the given Collection return type.
static java.lang.Class<?>	getCollectionReturnType(java.lang.reflect.Method method, int nestingLevel) Determine the generic element type of the given Collection return type.
static java.lang.Class<?>	getCollectionType(java.lang.Class<? extends java.util.Collection> collectionClass) Determine the generic element type of the given Collection class (if it declares one through a generic superclass or generic interface).
static java.lang.Class<?>	getMapKeyFieldType(java.lang.reflect.Field mapField) Determine the generic key type of the given Map field.
static java.lang.Class<?>	getMapKeyFieldType(java.lang.reflect.Field mapField, int nestingLevel) Determine the generic key type of the given Map field.
static java.lang.Class<?>	getMapKeyFieldType(java.lang.reflect.Field mapField, int nestingLevel, java.util.Map<java.lang.Integer,java.lang.Integer> typeIndexesPerLevel) Deprecated. as of 4.0, in favor of using ResolvableType for arbitrary nesting levels
static java.lang.Class<?>	getMapKeyParameterType(MethodParameter methodParam) Determine the generic key type of the given Map parameter.
static java.lang.Class<?>	getMapKeyReturnType(java.lang.reflect.Method method) Determine the generic key type of the given Map return type.
static java.lang.Class<?>	getMapKeyReturnType(java.lang.reflect.Method method, int nestingLevel) Determine the generic key type of the given Map return type.
static java.lang.Class<?>	getMapKeyType(java.lang.Class<? extends java.util.Map> mapClass) Determine the generic key type of the given Map class (if it declares one through a generic superclass or generic interface).
static java.lang.Class<?>	getMapValueFieldType(java.lang.reflect.Field mapField) Determine the generic value type of the given Map field.
static java.lang.Class<?>	getMapValueFieldType(java.lang.reflect.Field mapField, int nestingLevel) Determine the generic value type of the given Map field.
static java.lang.Class<?>	getMapValueFieldType(java.lang.reflect.Field mapField, int nestingLevel, java.util.Map<java.lang.Integer,java.lang.Integer> typeIndexesPerLevel) Deprecated. as of 4.0, in favor of using ResolvableType for arbitrary nesting levels
static java.lang.Class<?>	getMapValueParameterType(MethodParameter methodParam) Determine the generic value type of the given Map parameter.
static java.lang.Class<?>	getMapValueReturnType(java.lang.reflect.Method method) Determine the generic value type of the given Map return type.
static java.lang.Class<?>	getMapValueReturnType(java.lang.reflect.Method method, int nestingLevel) Determine the generic value type of the given Map return type.
static java.lang.Class<?>	getMapValueType(java.lang.Class<? extends java.util.Map> mapClass) Determine the generic value type of the given Map class (if it declares one through a generic superclass or generic interface).

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

GenericCollectionTypeResolver

public GenericCollectionTypeResolver()

Method Detail

getCollectionType

public static java.lang.Class<?> getCollectionType(java.lang.Class<? extends java.util.Collection> collectionClass)

Determine the generic element type of the given Collection class (if it declares one through a generic superclass or generic interface).

Parameters:

collectionClass - the collection class to introspect

Returns:

the generic type, or null if none

getMapKeyType

public static java.lang.Class<?> getMapKeyType(java.lang.Class<? extends java.util.Map> mapClass)

Determine the generic key type of the given Map class (if it declares one through a generic superclass or generic interface).

Parameters:

mapClass - the map class to introspect

Returns:

the generic type, or null if none

getMapValueType

public static java.lang.Class<?> getMapValueType(java.lang.Class<? extends java.util.Map> mapClass)

Determine the generic value type of the given Map class (if it declares one through a generic superclass or generic interface).

Parameters:

mapClass - the map class to introspect

Returns:

the generic type, or null if none

getCollectionFieldType

public static java.lang.Class<?> getCollectionFieldType(java.lang.reflect.Field collectionField)

Determine the generic element type of the given Collection field.

Parameters:

collectionField - the collection field to introspect

Returns:

the generic type, or null if none

getCollectionFieldType

public static java.lang.Class<?> getCollectionFieldType(java.lang.reflect.Field collectionField,
                                                        int nestingLevel)

Determine the generic element type of the given Collection field.

Parameters:

collectionField - the collection field to introspect

nestingLevel - the nesting level of the target type (typically 1; e.g. in case of a List of Lists, 1 would indicate the nested List, whereas 2 would indicate the element of the nested List)

Returns:

the generic type, or null if none

getCollectionFieldType

@Deprecated
public static java.lang.Class<?> getCollectionFieldType(java.lang.reflect.Field collectionField,
                                                                    int nestingLevel,
                                                                    java.util.Map<java.lang.Integer,java.lang.Integer> typeIndexesPerLevel)

Deprecated. as of 4.0, in favor of using ResolvableType for arbitrary nesting levels

Determine the generic element type of the given Collection field.

Parameters:

collectionField - the collection field to introspect

nestingLevel - the nesting level of the target type (typically 1; e.g. in case of a List of Lists, 1 would indicate the nested List, whereas 2 would indicate the element of the nested List)

typeIndexesPerLevel - Map keyed by nesting level, with each value expressing the type index for traversal at that level

Returns:

the generic type, or null if none

getMapKeyFieldType

public static java.lang.Class<?> getMapKeyFieldType(java.lang.reflect.Field mapField)

Determine the generic key type of the given Map field.

Parameters:

mapField - the map field to introspect

Returns:

the generic type, or null if none

getMapKeyFieldType

public static java.lang.Class<?> getMapKeyFieldType(java.lang.reflect.Field mapField,
                                                    int nestingLevel)

Determine the generic key type of the given Map field.

Parameters:

mapField - the map field to introspect

nestingLevel - the nesting level of the target type (typically 1; e.g. in case of a List of Lists, 1 would indicate the nested List, whereas 2 would indicate the element of the nested List)

Returns:

the generic type, or null if none

getMapKeyFieldType

@Deprecated
public static java.lang.Class<?> getMapKeyFieldType(java.lang.reflect.Field mapField,
                                                                int nestingLevel,
                                                                java.util.Map<java.lang.Integer,java.lang.Integer> typeIndexesPerLevel)

Deprecated. as of 4.0, in favor of using ResolvableType for arbitrary nesting levels

Determine the generic key type of the given Map field.

Parameters:

mapField - the map field to introspect

nestingLevel - the nesting level of the target type (typically 1; e.g. in case of a List of Lists, 1 would indicate the nested List, whereas 2 would indicate the element of the nested List)

typeIndexesPerLevel - Map keyed by nesting level, with each value expressing the type index for traversal at that level

Returns:

the generic type, or null if none

getMapValueFieldType

public static java.lang.Class<?> getMapValueFieldType(java.lang.reflect.Field mapField)

Determine the generic value type of the given Map field.

Parameters:

mapField - the map field to introspect

Returns:

the generic type, or null if none

getMapValueFieldType

public static java.lang.Class<?> getMapValueFieldType(java.lang.reflect.Field mapField,
                                                      int nestingLevel)

Determine the generic value type of the given Map field.

Parameters:

mapField - the map field to introspect

nestingLevel - the nesting level of the target type (typically 1; e.g. in case of a List of Lists, 1 would indicate the nested List, whereas 2 would indicate the element of the nested List)

Returns:

the generic type, or null if none

getMapValueFieldType

@Deprecated
public static java.lang.Class<?> getMapValueFieldType(java.lang.reflect.Field mapField,
                                                                  int nestingLevel,
                                                                  java.util.Map<java.lang.Integer,java.lang.Integer> typeIndexesPerLevel)

Deprecated. as of 4.0, in favor of using ResolvableType for arbitrary nesting levels

Determine the generic value type of the given Map field.

Parameters:

mapField - the map field to introspect

nestingLevel - the nesting level of the target type (typically 1; e.g. in case of a List of Lists, 1 would indicate the nested List, whereas 2 would indicate the element of the nested List)

typeIndexesPerLevel - Map keyed by nesting level, with each value expressing the type index for traversal at that level

Returns:

the generic type, or null if none

getCollectionParameterType

public static java.lang.Class<?> getCollectionParameterType(MethodParameter methodParam)

Determine the generic element type of the given Collection parameter.

Parameters:

methodParam - the method parameter specification

Returns:

the generic type, or null if none

getMapKeyParameterType

public static java.lang.Class<?> getMapKeyParameterType(MethodParameter methodParam)

Determine the generic key type of the given Map parameter.

Parameters:

methodParam - the method parameter specification

Returns:

the generic type, or null if none

getMapValueParameterType

public static java.lang.Class<?> getMapValueParameterType(MethodParameter methodParam)

Determine the generic value type of the given Map parameter.

Parameters:

methodParam - the method parameter specification

Returns:

the generic type, or null if none

getCollectionReturnType

public static java.lang.Class<?> getCollectionReturnType(java.lang.reflect.Method method)

Determine the generic element type of the given Collection return type.

Parameters:

method - the method to check the return type for

Returns:

the generic type, or null if none

getCollectionReturnType

public static java.lang.Class<?> getCollectionReturnType(java.lang.reflect.Method method,
                                                         int nestingLevel)

Determine the generic element type of the given Collection return type.

If the specified nesting level is higher than 1, the element type of a nested Collection/Map will be analyzed.

Parameters:

method - the method to check the return type for

nestingLevel - the nesting level of the target type (typically 1; e.g. in case of a List of Lists, 1 would indicate the nested List, whereas 2 would indicate the element of the nested List)

Returns:

the generic type, or null if none

getMapKeyReturnType

public static java.lang.Class<?> getMapKeyReturnType(java.lang.reflect.Method method)

Determine the generic key type of the given Map return type.

Parameters:

method - the method to check the return type for

Returns:

the generic type, or null if none

getMapKeyReturnType

public static java.lang.Class<?> getMapKeyReturnType(java.lang.reflect.Method method,
                                                     int nestingLevel)

Determine the generic key type of the given Map return type.

Parameters:

method - the method to check the return type for

nestingLevel - the nesting level of the target type (typically 1; e.g. in case of a List of Lists, 1 would indicate the nested List, whereas 2 would indicate the element of the nested List)

Returns:

the generic type, or null if none

getMapValueReturnType

public static java.lang.Class<?> getMapValueReturnType(java.lang.reflect.Method method)

Determine the generic value type of the given Map return type.

Parameters:

method - the method to check the return type for

Returns:

the generic type, or null if none

getMapValueReturnType

public static java.lang.Class<?> getMapValueReturnType(java.lang.reflect.Method method,
                                                       int nestingLevel)

Determine the generic value type of the given Map return type.

Parameters:

method - the method to check the return type for

nestingLevel - the nesting level of the target type (typically 1; e.g. in case of a List of Lists, 1 would indicate the nested List, whereas 2 would indicate the element of the nested List)

Returns:

the generic type, or null if none