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https://issues.apache.org/jira/browse/JENA-1233?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15629297#comment-15629297
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Andy Seaborne commented on JENA-1233:
-------------------------------------
The output is correct - BEFORE and AFTER are written into the
ObjectOutputStream with a triple in between. It shows that other data can be
mixed in.
AFTER is printed as "string2"
Annotated:
{noformat}
public static void exTriple() throws IOException, ClassNotFoundException {
ByteArrayOutputStream out = new ByteArrayOutputStream() ;
ObjectOutputStream oos = new ObjectOutputStream(out) ;
Node n = NodeFactory.createBlankNode() ;
Triple x = Triple.create(n, SSE.parseNode(":predicate"), n) ;
oos.writeObject("BEFORE"); // **** Insert BEFORE into the
object stream.
oos.writeObject(new STriple(x)); // **** Insert triple
oos.writeObject("AFTER"); // **** Insert AFTER into the object
stream.
byte b[] = out.toByteArray() ;
ObjectInputStream ois = new ObjectInputStream(new
ByteArrayInputStream(b)) ;
String string1 = (String)(ois.readObject()) ; // **** From object
stream -> BEFORE
STriple s = (STriple)(ois.readObject()) ; // **** From object
stream -> triple
String string2 = (String)(ois.readObject()) ; // **** From object
stream -> AFTER
System.out.println(string1) ; // Output "BEFORE"
SSE.write(s.getTriple()); // Output triple.
System.out.println() ;
System.out.println(string2) ; // Output "AFTER"
}
{noformat}
> Make RDF primitives Serializable
> --------------------------------
>
> Key: JENA-1233
> URL: https://issues.apache.org/jira/browse/JENA-1233
> Project: Apache Jena
> Issue Type: Improvement
> Components: Elephas
> Affects Versions: Jena 3.1.0
> Reporter: Itsuki Toyota
>
> I always use Jena when I handle RDF data with Apache Spark.
> However, when I want to store resulting RDD data (ex. RDD[Triple]) in binary
> format, I can't call RDD.saveAsObjectFile method.
> It's because RDD.saveAsObjectFile requires java.io.Serializable interface.
> See the following code.
> https://github.com/apache/spark/blob/v1.6.0/core/src/main/scala/org/apache/spark/rdd/RDD.scala#L1469
> https://github.com/apache/spark/blob/v1.6.0/core/src/main/scala/org/apache/spark/util/Utils.scala#L79-L86
> You can see that
> 1) RDD.saveAsObjectFile calls Util.serialize method
> 2) Util.serialize method requires the RDD-wrapped object implementing
> java.io.Serializable interface. For example, if you want to save a
> RDD[Triple] object, Triple must implements java.io.Serializable.
> So why not implement java.io.Serializable ?
> I think it will improve the usability in Apache Spark.
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