eu.fbk.knowledgestore

Class Outcome

java.lang.Object

eu.fbk.knowledgestore.Outcome

All Implemented Interfaces:

Serializable, Comparable<Outcome>

public final class Outcome
extends Object
implements Comparable<Outcome>, Serializable

The outcome of the invocation of a KnowledgeStore operation.

An Outcome instance encodes the outcome of an Operation invocation. It stores:

• the Outcome.Status code specifying whether and how the invocation was successful or failed (see getStatus());
• the invocation ID, which is generated by the system and may link to additional information logged on client/server sides (see getInvocationID());
• an optional object ID, in case the invocation was applied to a specific object (see getObjectID());
• an optional message, providing additional information about the outcome (see getMessage())

Outcome instances can be created using one of the static factory methods create(Status, URI), create(Status, URI, URI), create(Status, URI, URI, String). Equality and comparison are performed based on the invocation ID. This class is immutable and thus thread safe.

See Also:

Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	Outcome.Status Enumeration of Outcome status codes.

Method Summary

Modifier and Type	Method and Description
int	compareTo(Outcome other) Comparison is done on the invocation ID.
static Outcome	create(Outcome.Status status, org.openrdf.model.URI invocationID) Creates a new Outcome with the status code and invocation ID supplied.
static Outcome	create(Outcome.Status status, org.openrdf.model.URI invocationID, org.openrdf.model.URI objectID) Creates a new Outcome with the status code, invocation ID and optional object ID supplied.
static Outcome	create(Outcome.Status status, org.openrdf.model.URI invocationID, org.openrdf.model.URI objectID, String message) Creates a new Outcome with the status code, invocation ID, optional object ID and optional message supplied.
static Outcome	create(Record record) Creates a new Outcome starting from the Record supplied.
static Stream<Outcome>	decode(Stream<org.openrdf.model.Statement> stream, Boolean chunked) Performs RDF-to-outcome decoding by converting a stream of RDF statements in a stream of outcomes.
static Stream<org.openrdf.model.Statement>	encode(Stream<? extends Outcome> stream) Performs outcome-to-RDF encoding by converting a stream of outcomes in a stream of RDF statements.
boolean	equals(Object object) Two Outcome instances are equal if the have the same invocation ID.
org.openrdf.model.URI	getInvocationID() Returns the ID of the invocation, which may link to relevant logged information.
String	getMessage() Return an optional message providing further information about the outcome.
org.openrdf.model.URI	getObjectID() Returns the ID of the processed object, if applicable.
Outcome.Status	getStatus() Returns the status code for this outcome.
int	hashCode() The returned code depends on the invocation ID.
Record	toRecord() Return a Record version of this Outcome object.
String	toString() The method returns a string of the form status invocationID (objectID) message.

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Method Detail

create

public static Outcome create(Outcome.Status status,
                             org.openrdf.model.URI invocationID)

Creates a new Outcome with the status code and invocation ID supplied.

Parameters:

status - the status code, not null

invocationID - the invocation ID, not null

Returns:

the created Outcome

create

public static Outcome create(Outcome.Status status,
                             org.openrdf.model.URI invocationID,
                             @Nullable
                             org.openrdf.model.URI objectID)

Creates a new Outcome with the status code, invocation ID and optional object ID supplied.

Parameters:

status - the status code, not null

invocationID - the invocation ID, not null

objectID - the optional object ID, possibly null

Returns:

the created Outcome

create

public static Outcome create(Outcome.Status status,
                             org.openrdf.model.URI invocationID,
                             @Nullable
                             org.openrdf.model.URI objectID,
                             @Nullable
                             String message)

Creates a new Outcome with the status code, invocation ID, optional object ID and optional message supplied.

Parameters:

status - the status code, not null

invocationID - the invocation ID, not null

objectID - the optional object ID, possibly null

message - the optional message, possibly null

Returns:

the created Outcome

create

public static Outcome create(Record record)

Creates a new Outcome starting from the Record supplied. The record ID is used as the invocation ID, while properties KSR.STATUS, KSR.OBJECT and KSR.MESSAGE are read, respectively, to recover the status code, the optional object ID and the optional message.

Parameters:

record - the record

Returns:

the created Outcome

getStatus

public Outcome.Status getStatus()

Returns the status code for this outcome. This property can be checked to determine whether the invocation was successful or resulted in an error, with different status codes specifying different success or error conditions.

Returns:

the status code, not null

getInvocationID

public org.openrdf.model.URI getInvocationID()

Returns the ID of the invocation, which may link to relevant logged information.

Returns:

the invocation ID, not null

getObjectID

@Nullable
public org.openrdf.model.URI getObjectID()

Returns the ID of the processed object, if applicable.

Returns:

the object ID, null if not applicable

getMessage

@Nullable
public String getMessage()

Return an optional message providing further information about the outcome.

Returns:

the optional message

compareTo

public int compareTo(Outcome other)

Comparison is done on the invocation ID.

Specified by:

compareTo in interface Comparable<Outcome>

equals

public boolean equals(@Nullable
                      Object object)

Two Outcome instances are equal if the have the same invocation ID.

Overrides:

equals in class Object

hashCode

public int hashCode()

The returned code depends on the invocation ID.

Overrides:

hashCode in class Object

toRecord

public Record toRecord()

Return a Record version of this Outcome object. The returned record is identified by this invocation ID; it is associated to the status URI via property KSR.STATUS, to the optional object ID via property KSR.OBJECT and to the optional message via property KSR.MESSAGE.

Returns:

the corresponding record

toString

public String toString()

The method returns a string of the form status invocationID (objectID) message.

Overrides:

toString in class Object

encode

public static Stream<org.openrdf.model.Statement> encode(Stream<? extends Outcome> stream)

Performs outcome-to-RDF encoding by converting a stream of outcomes in a stream of RDF statements.

Parameters:

stream - the stream of outcomes to encode.

Returns:

the resulting stream of statements

decode

public static Stream<Outcome> decode(Stream<org.openrdf.model.Statement> stream,
                                     @Nullable
                                     Boolean chunked)

Performs RDF-to-outcome decoding by converting a stream of RDF statements in a stream of outcomes. Parameter chunked specifies whether the input statement stream is chunked, i.e., organized as a sequence of statement chunks with each chunk containing the statements for an outcome. Chunked RDF streams noticeably speed up decoding, and are always produced by the KnowledgeStore API. Chunking information may be set to null (e.g., because unknown at the time the method is called): in this case, it will be read from metadata attribute "chunked" attached to the stream; reading will happen just before decoding will take place, i.e., when a terminal stream operation will be called.

Parameters:

stream - the stream of statements to decode

chunked - true if the input statement stream is chunked, null if to be read from stream metadata

Returns:

the resulting stream of outcomes