net.cnri.dobj

Interface DOOperation

All Known Implementing Classes:

AbstractDelegationOperations, AuditHookImpl, ExternalInterface, ListElementDelegationOperations, LuceneIndexer, MatrixOps, ReplicationOperator, StandardOperations, StandardOperations

public interface DOOperation

Objects implementing the DOOperation interface can be used to perform an operation on a digital object in a repository.

Method Summary

Methods

Modifier and Type	Method and Description
boolean	canHandleOperation(DOOperationContext context) Returns true iff this object can perform the given operation on behalf of the caller on the given object.
java.lang.String[]	listOperations(DOOperationContext context) Returns a list of operations that this operator can perform on the object identified by the DOOperationContext parameter.
void	performOperation(DOOperationContext context, java.io.InputStream in, java.io.OutputStream out) Performs the given operation (which this object has advertised that it can handle) which consists of reading input (if any is expected) from the given InputStream and writing the output of the operation (if any) to the OutputStream.

Method Detail

canHandleOperation

boolean canHandleOperation(DOOperationContext context)

Returns true iff this object can perform the given operation on behalf of the caller on the given object. The operation, object, caller, and request parameters are all provided by the given DOOperationContext object.

listOperations

java.lang.String[] listOperations(DOOperationContext context)

Returns a list of operations that this operator can perform on the object identified by the DOOperationContext parameter.

performOperation

void performOperation(DOOperationContext context,
                    java.io.InputStream in,
                    java.io.OutputStream out)

Performs the given operation (which this object has advertised that it can handle) which consists of reading input (if any is expected) from the given InputStream and writing the output of the operation (if any) to the OutputStream. This method should always close the input and output streams when finished with them. If there are any errors in the input, the error message must be communicated on the OutputStream since all errors must be at the application level. Any exceptions thrown by this method will *not* be communicated to the caller and are therefore not acceptable.