RetrievalMethod (Java SE 12 & JDK 12 )

All Superinterfaces:

URIReference, XMLStructure
```
public interface RetrievalMethod
extends URIReference, XMLStructure
```
A representation of the XML RetrievalMethod element as defined in the W3C Recommendation for XML-Signature Syntax and Processing. A RetrievalMethod object is used to convey a reference to KeyInfo information that is stored at another location. The XML schema definition is defined as:
```
   <element name="RetrievalMethod" type="ds:RetrievalMethodType"/>
   <complexType name="RetrievalMethodType">
     <sequence>
       <element name="Transforms" type="ds:TransformsType" minOccurs="0"/>
     </sequence>
     <attribute name="URI" type="anyURI"/>
     <attribute name="Type" type="anyURI" use="optional"/>
   </complexType>
 
```
A RetrievalMethod instance may be created by invoking one of the newRetrievalMethod methods of the KeyInfoFactory class, and passing it the URI identifying the location of the KeyInfo, an optional type URI identifying the type of KeyInfo, and an optional list of Transforms; for example:
```
   KeyInfoFactory factory = KeyInfoFactory.getInstance("DOM");
   RetrievalMethod rm = factory.newRetrievalMethod
      ("#KeyValue-1", KeyValue.DSA_TYPE, Collections.singletonList(Transform.BASE64));
 
```
Since:

1.6

See Also:

KeyInfoFactory.newRetrievalMethod(String), KeyInfoFactory.newRetrievalMethod(String, String, List)

Method Summary

Modifier and Type	Method	Description
`Data`	`dereference(XMLCryptoContext context)`	Dereferences the `KeyInfo` information referenced by this `RetrievalMethod` and applies the specified `Transform`s.
`List<Transform>`	`getTransforms()`	Returns an `unmodifiable list` of `Transform`s of this `RetrievalMethod`.
`String`	`getURI()`	Returns the URI of the referenced `KeyInfo` information.

Methods declared in interface javax.xml.crypto.URIReference
getType

Methods declared in interface javax.xml.crypto.XMLStructure
isFeatureSupported

- Method Detail
  - getTransforms
```
List<Transform> getTransforms()
```
    Returns an unmodifiable list of Transforms of this RetrievalMethod.
    
    Returns:
    
    an unmodifiable list of Transform objects (may be empty but never null).
  - getURI
```
String getURI()
```
    Returns the URI of the referenced KeyInfo information.
    
    Specified by:
    
    getURI in interface URIReference
    
    Returns:
    
    the URI of the referenced KeyInfo information in RFC 2396 format (never null)
  - dereference
```
Data dereference(XMLCryptoContext context)
          throws URIReferenceException
```
    Dereferences the KeyInfo information referenced by this RetrievalMethod and applies the specified Transforms.
    
    Parameters:
    
    context - an XMLCryptoContext that may contain additional useful information for dereferencing the URI. The context's baseURI and dereferencer parameters (if specified) are used to resolve and dereference this RetrievalMethod
    
    Returns:
    
    a Data object representing the raw contents of the KeyInfo information referenced by this RetrievalMethod. It is the caller's responsibility to convert the returned data to an appropriate KeyInfo object.
    
    Throws:
    
    NullPointerException - if context is null
    
    URIReferenceException - if there is an error while dereferencing