Top Description Inners Methods
org.springframework.core.convert.converter

public Interface GenericConverter

Known Direct Subinterfaces
org.springframework.core.convert.converter.ConditionalGenericConverter
Known Direct Implementers
org.springframework.core.convert.support.GenericConversionService.NoOpConverter
Imports
java.util.Set, org.springframework.core.convert.TypeDescriptor, org.springframework.lang.Nullable, org.springframework.util.Assert
Generic converter interface for converting between two or more types.

This is the most flexible of the Converter SPI interfaces, but also the most complex. It is flexible in that a GenericConverter may support converting between multiple source/target type pairs (see getConvertibleTypes()). In addition, GenericConverter implementations have access to source/target field context during the type conversion process. This allows for resolving source and target field metadata such as annotations and generics information, which can be used to influence the conversion logic.

This interface should generally not be used when the simpler Converter or ConverterFactory interface is sufficient.

Implementations may additionally implement ConditionalConverter.

Authors
Keith Donald, Juergen Hoeller
Since
3.0
See Also
TypeDescriptor, Converter, ConverterFactory, ConditionalConverter

Nested and Inner Type Summary

Modifier and TypeClass and Description
public static class
GenericConverter.ConvertiblePair

Holder for a source-to-target class pair.

Method Summary

Modifier and TypeMethod and Description
public Object

Returns:

the converted object
convert(Object
the source object to convert (may be null)
source, TypeDescriptor
the type descriptor of the field we are converting from
sourceType, TypeDescriptor
the type descriptor of the field we are converting to
targetType)

Convert the source object to the targetType described by the TypeDescriptor.

public Set<GenericConverter.ConvertiblePair>
getConvertibleTypes()

Return the source and target types that this converter can convert between.

Method Detail

convertback to summary
public Object convert(Object source, TypeDescriptor sourceType, TypeDescriptor targetType)

Convert the source object to the targetType described by the TypeDescriptor.

Parameters
source:Object

the source object to convert (may be null)

sourceType:TypeDescriptor

the type descriptor of the field we are converting from

targetType:TypeDescriptor

the type descriptor of the field we are converting to

Returns:Object

the converted object

Annotations
@Nullable
getConvertibleTypesback to summary
public Set<GenericConverter.ConvertiblePair> getConvertibleTypes()

Return the source and target types that this converter can convert between.

Each entry is a convertible source-to-target type pair.

For conditional converters this method may return null to indicate all source-to-target pairs should be considered.

Annotations
@Nullable
org.springframework.core.convert.converter back to summary

public final Class GenericConverter.ConvertiblePair

extends Object
Class Inheritance
  • java.lang.Object
  • org.springframework.core.convert.converter.GenericConverter.ConvertiblePair
Holder for a source-to-target class pair.

Field Summary

Modifier and TypeField and Description
private final Class<?>
sourceType

private final Class<?>
targetType

Constructor Summary

AccessConstructor and Description
public
ConvertiblePair(Class<?>
the source type
sourceType, Class<?>
the target type
targetType)

Create a new source-to-target pair.

Method Summary

Modifier and TypeMethod and Description
public boolean
equals(Object
the reference object with which to compare.
other)

Overrides java.lang.Object.equals.

Indicates whether some other object is "equal to" this one.

public Class<?>
getSourceType()

public Class<?>
getTargetType()

public int
hashCode()

Overrides java.lang.Object.hashCode.

Returns a hash code value for this object.

public String
toString()

Overrides java.lang.Object.toString.

Returns a string representation of the object.

Inherited from java.lang.Object:
clonefinalizegetClassnotifynotifyAllwaitwaitwait

Field Detail

sourceTypeback to summary
private final Class<?> sourceType
targetTypeback to summary
private final Class<?> targetType

Constructor Detail

ConvertiblePairback to summary
public ConvertiblePair(Class<?> sourceType, Class<?> targetType)

Create a new source-to-target pair.

Parameters
sourceType:Class<?>

the source type

targetType:Class<?>

the target type

Method Detail

equalsback to summary
public boolean equals(Object other)

Overrides java.lang.Object.equals.

Doc from java.lang.Object.equals.

Indicates whether some other object is "equal to" this one.

The equals method implements an equivalence relation on non-null object references:

  • It is reflexive: for any non-null reference value x, x.equals(x) should return true.
  • It is symmetric: for any non-null reference values x and y, x.equals(y) should return true if and only if y.equals(x) returns true.
  • It is transitive: for any non-null reference values x, y, and z, if x.equals(y) returns true and y.equals(z) returns true, then x.equals(z) should return true.
  • It is consistent: for any non-null reference values x and y, multiple invocations of x.equals(y) consistently return true or consistently return false, provided no information used in equals comparisons on the objects is modified.
  • For any non-null reference value x, x.equals(null) should return false.

An equivalence relation partitions the elements it operates on into equivalence classes; all the members of an equivalence class are equal to each other. Members of an equivalence class are substitutable for each other, at least for some purposes.

Parameters
other:Object

the reference object with which to compare.

Returns:boolean

true if this object is the same as the obj argument; false otherwise.

Annotations
@Override
getSourceTypeback to summary
public Class<?> getSourceType()
getTargetTypeback to summary
public Class<?> getTargetType()
hashCodeback to summary
public int hashCode()

Overrides java.lang.Object.hashCode.

Doc from java.lang.Object.hashCode.

Returns a hash code value for this object. This method is supported for the benefit of hash tables such as those provided by java.util.HashMap.

The general contract of hashCode is:

  • Whenever it is invoked on the same object more than once during an execution of a Java application, the hashCode method must consistently return the same integer, provided no information used in equals comparisons on the object is modified. This integer need not remain consistent from one execution of an application to another execution of the same application.
  • If two objects are equal according to the equals method, then calling the hashCode method on each of the two objects must produce the same integer result.
  • It is not required that if two objects are unequal according to the equals method, then calling the hashCode method on each of the two objects must produce distinct integer results. However, the programmer should be aware that producing distinct integer results for unequal objects may improve the performance of hash tables.
Returns:int

a hash code value for this object

Annotations
@Override
toStringback to summary
public String toString()

Overrides java.lang.Object.toString.

Doc from java.lang.Object.toString.

Returns a string representation of the object. Satisfying this method's contract implies a non-null result must be returned.

Returns:String

a string representation of the object

Annotations
@Override