Java™ Platform
Standard Ed. 6

javax.xml.crypto.dsig
Interface Reference

All Superinterfaces:
URIReference, XMLStructure

public interface Reference
extends URIReference, XMLStructure

A representation of the Reference element as defined in the W3C Recommendation for XML-Signature Syntax and Processing. The XML schema is defined as:

 <element name="Reference" type="ds:ReferenceType"/>
 <complexType name="ReferenceType">
   <sequence>
     <element ref="ds:Transforms" minOccurs="0"/>
     <element ref="ds:DigestMethod"/>
     <element ref="ds:DigestValue"/>
   </sequence>
   <attribute name="Id" type="ID" use="optional"/>
   <attribute name="URI" type="anyURI" use="optional"/>
   <attribute name="Type" type="anyURI" use="optional"/>
 </complexType>

 <element name="DigestValue" type="ds:DigestValueType"/>
 <simpleType name="DigestValueType">
   <restriction base="base64Binary"/>
 </simpleType>
 

A Reference instance may be created by invoking one of the newReference methods of the XMLSignatureFactory class; for example:

   XMLSignatureFactory factory = XMLSignatureFactory.getInstance("DOM");
   Reference ref = factory.newReference
     ("http://www.ietf.org/rfc/rfc3275.txt", 
        factory.newDigestMethod(DigestMethod.SHA1, null));
 

Since:
1.6
See Also:
XMLSignatureFactory.newReference(String, DigestMethod), XMLSignatureFactory.newReference(String, DigestMethod, List, String, String)

Method Summary
 byte[] getCalculatedDigestValue()
          Returns the calculated digest value of this Reference after a validation operation.
 Data getDereferencedData()
          Returns the dereferenced data, if reference caching is enabled.
 InputStream getDigestInputStream()
          Returns the pre-digested input stream, if reference caching is enabled.
 DigestMethod getDigestMethod()
          Returns the digest method of this Reference.
 byte[] getDigestValue()
          Returns the digest value of this Reference.
 String getId()
          Returns the optional Id attribute of this Reference, which permits this reference to be referenced from elsewhere.
 List getTransforms()
          Returns an unmodifiable list of Transforms that are contained in this Reference.
 boolean validate(XMLValidateContext validateContext)
          Validates this reference.
 
Methods inherited from interface javax.xml.crypto.URIReference
getType, getURI
 
Methods inherited from interface javax.xml.crypto.XMLStructure
isFeatureSupported
 

Method Detail

getTransforms

List getTransforms()
Returns an unmodifiable list of Transforms that are contained in this Reference.

Returns:
an unmodifiable list of Transforms (may be empty but never null)

getDigestMethod

DigestMethod getDigestMethod()
Returns the digest method of this Reference.

Returns:
the digest method

getId

String getId()
Returns the optional Id attribute of this Reference, which permits this reference to be referenced from elsewhere.

Returns:
the Id attribute (may be null if not specified)

getDigestValue

byte[] getDigestValue()
Returns the digest value of this Reference.

Returns:
the raw digest value, or null if this reference has not been digested yet. Each invocation of this method returns a new clone to protect against subsequent modification.

getCalculatedDigestValue

byte[] getCalculatedDigestValue()
Returns the calculated digest value of this Reference after a validation operation. This method is useful for debugging if the reference fails to validate.

Returns:
the calculated digest value, or null if this reference has not been validated yet. Each invocation of this method returns a new clone to protect against subsequent modification.

validate

boolean validate(XMLValidateContext validateContext)
                 throws XMLSignatureException
Validates this reference. This method verifies the digest of this reference.

This method only validates the reference the first time it is invoked. On subsequent invocations, it returns a cached result.

Parameters:
validateContext - the validating context
Returns:
true if this reference was validated successfully; false otherwise
Throws:
NullPointerException - if validateContext is null
XMLSignatureException - if an unexpected exception occurs while validating the reference

getDereferencedData

Data getDereferencedData()
Returns the dereferenced data, if reference caching is enabled. This is the result of dereferencing the URI of this reference during a validation or generation operation.

Returns:
the dereferenced data, or null if reference caching is not enabled or this reference has not been generated or validated

getDigestInputStream

InputStream getDigestInputStream()
Returns the pre-digested input stream, if reference caching is enabled. This is the input to the digest operation during a validation or signing operation.

Returns:
an input stream containing the pre-digested input, or null if reference caching is not enabled or this reference has not been generated or validated

Java™ Platform
Standard Ed. 6

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For further API reference and developer documentation, see Java SE Developer Documentation. That documentation contains more detailed, developer-targeted descriptions, with conceptual overviews, definitions of terms, workarounds, and working code examples.

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