com.highqsoft.corbafileserver

Interface StreamObject

All Superinterfaces:

java.lang.Comparable<StreamObject>

public interface StreamObject
extends java.lang.Comparable<StreamObject>

An interface designed to work with the StreamHandlerIF. The handler creates StreamObjects to represent resources in the backend of its implementation. StreamObjects are designed to provide access to one of the resources.

Author:

Alexander Ziller, HighQSoft GmbH

Method Summary

Methods

Modifier and Type	Method and Description
boolean	exists() The return value of this method indicated wether the object already exists in the backend.
java.lang.String	getIdentifier() Returns an identifier for the resource which this object represents.
java.io.InputStream	getInput() Returns an input from the resource represented by this object.
java.util.Map<java.lang.String,?>	getInputProperties() Returns the properties of the object represented by inputstream of this interface.
java.io.OutputStream	getOutput(java.util.Map<java.lang.String,java.lang.Object> properties) Returns an output from the resource represented by this object.

Methods inherited from interface java.lang.Comparable

compareTo

Method Detail

getOutput

java.io.OutputStream getOutput(java.util.Map<java.lang.String,java.lang.Object> properties)
                               throws java.io.IOException

Returns an output from the resource represented by this object. The method will always return the same output. If a caller closes the output by himself, the returned object may no longer be useful.
The given argument represents the properties of the object that is going to be written to the outputstream of this object. The supported properties depend on the implementation.
If the implementation cannot return an output, an IOException is thrown.

Parameters:

properties - the optional properties assigned with the object to be written with this stream. Can be null

Returns:

Throws:

java.io.IOException

getInput

java.io.InputStream getInput()
                             throws java.io.IOException

Returns an input from the resource represented by this object. The method will always return the same input. If a caller closes the input by himself, the returned object may no longer be useful.

The returned InputStream MUST be closed by the caller in order to avoid resource leaks and memory issues.
If the implementation cannot return an input, an IOException is thrown.

Returns:

Throws:

java.io.IOException

getIdentifier

java.lang.String getIdentifier()

Returns an identifier for the resource which this object represents. The identifier must uniquely identify every resource on the backend.

Returns:

getInputProperties

java.util.Map<java.lang.String,?> getInputProperties()
                                                     throws java.io.IOException

Returns the properties of the object represented by inputstream of this interface. The returned value is a map containing all properties that the implementation was able to retrieve from the backend. If the inputstream is not available, then this method will return null.

Returns:

the properties or null if it cannot be determined

Throws:

java.io.IOException - thrown if the properties were requested before the actual input stream is opened by caller

exists

boolean exists()
               throws java.io.IOException

The return value of this method indicated wether the object already exists in the backend. If the return value is TRUE, then the object will be overridden when the output stream is used to write data to it.

Returns:

TRUE if the object exists in the backend, false if not

Throws:

java.io.IOException - thrown if the status cannot be obtained