com.highqsoft.corbafileserver

Interface StreamHandlerIF

public interface StreamHandlerIF

A handler similar to the FilenameHandlerExtIF but instead of File objects, this interface is designed to handle streams. In order to identify streams other than by the java instance, the creates streams are encapsulated into a seperate StreamObject. Each of those objects can provide access to the streams of the resource it represents and the identifier used to map streams to their objects in the backend and on client side.

The implementation is used by the dynamic pugin loading of the CORBAFileServer. Thus, each implementation MUST have at least one of the following constructors:

• empty Constructor, no arguments
• Constructor with 1 argument, being a Properties object.

Author:

alex

Method Summary

Methods

Modifier and Type	Method and Description
void	copyObject(StreamObject src, StreamObject dst) Copies the given src object to the given dst object.
void	deleteObject(StreamObject sObj) Deletes the resources in the backend represented by the given StreamObject.
StreamObject	getObjectForIdentifier(AoSession session, java.lang.String identifier) Returns a StreamObject for the given parameters.
StreamObject	getObjectForInstance(AoSession session, java.lang.String name, java.lang.String subdir, T_LONGLONG aid, T_LONGLONG iid) Returns an object that represents the resource in the backend of the implementation.
void	moveObject(StreamObject src, StreamObject dst) Moves the given StreamObject src to the location given in the dst object.

Method Detail

getObjectForInstance

StreamObject getObjectForInstance(AoSession session,
                                java.lang.String name,
                                java.lang.String subdir,
                                T_LONGLONG aid,
                                T_LONGLONG iid)
                                  throws java.io.IOException

Returns an object that represents the resource in the backend of the implementation. Every call to this method with the same parameters might return a different object. However, the objects are refer to the same resource in the backend.

It is not guaranteed that the returned object can produce an input. It is however guaranteed that the output of the returned object works.

Parameters:

session - an AoSession

name - the name of the resource

subdir - a possible subdir where the resource should be located

aid - an optional ApplicationElement ID

iid - an optional InstanceElement ID

Returns:

an object representing access to the resource in the backend

Throws:

java.io.IOException

getObjectForIdentifier

StreamObject getObjectForIdentifier(AoSession session,
                                  java.lang.String identifier)
                                    throws java.io.IOException

Returns a StreamObject for the given parameters. Multiple calls to the method with identical parameters must return an object pointing to the same resource in the backend. The implementation does not have to return the exact same object. A comparison with equals is not recommended. If the identifier cannot be used to create a return object, the method returns null

Parameters:

session - an AoSession

identifier - a unique URL or other string-based identifier that the implementation understands

Returns:

an object that provides access to the resource in the backend

Throws:

java.io.IOException

deleteObject

void deleteObject(StreamObject sObj)
                  throws java.io.IOException

Deletes the resources in the backend represented by the given StreamObject.

Parameters:

sObj - the object describing the resource

Throws:

java.io.IOException - thrown if the given object cannot be deleted in the backend

moveObject

void moveObject(StreamObject src,
              StreamObject dst)
                throws java.io.IOException

Moves the given StreamObject src to the location given in the dst object. If the dst object represents an already existing object in the backend, the method will overwrite that object.
It may be necessary to know the implementation in order to create a valid dst object.

Parameters:

src -

dst -

Throws:

java.io.IOException - thrown if the implementation cannot handle the request with the given arguments.

copyObject

void copyObject(StreamObject src,
              StreamObject dst)
                throws java.io.IOException

Copies the given src object to the given dst object. If the dst object already exists, it will be overridden. In order to provided a valid dst object, the creator of the object mght

Parameters:

src -

dst -

Throws:

java.io.IOException