jpl.eda.archive
Class ArchiveProductHandler

java.lang.Object
  jpl.eda.archive.ArchiveProductHandler

All Implemented Interfaces:

jpl.eda.product.LargeProductQueryHandler, jpl.eda.product.QueryHandler

public class ArchiveProductHandler

extends java.lang.Object

implements jpl.eda.product.LargeProductQueryHandler

This class implements the LargeProductQueryHandler interface enabling a Product Server to access the Catalog and Archive Service (CAS).

In order to use this handler the following property must be specified for the Product Server as follows:

<key>jpl.eda.product.handlers</key>
<value>jpl.eda.archive.ArchiveProductHandler</value>

This class uses the following property:

• jpl.eda.archive.ArchiveProductHandler.archiveServerName
  Must contain the name of the Catalog and Archive Service. For example, urn:eda:rmi:JPL.Test.Archive.

The above property may be defined in the Product Server's properties element.

Version:

$Revision: 1.3 $

Author:

S. Hardman

Constructor Summary

ArchiveProductHandler()

Method Summary

void	close(java.lang.String id) Notify the server that a particular file transfer has completed.
static void	main(java.lang.String[] argv) Execute the large product handler.
jpl.eda.xmlquery.XMLQuery	query(jpl.eda.xmlquery.XMLQuery xmlQuery) Query for the result set associated with the given product.
byte[]	retrieveChunk(java.lang.String id, long offset, int length) Retrieve a fragment of the data from the specified file.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

ArchiveProductHandler

public ArchiveProductHandler()

Method Detail

query

public jpl.eda.xmlquery.XMLQuery query(jpl.eda.xmlquery.XMLQuery xmlQuery)
                                throws jpl.eda.product.ProductException

Query for the result set associated with the given product. The result set will consist of each file associated with the product that is locally archived. Files which are stored as remote references are not added to the result set. The query should resemble the following:

• CAS.ProductId = {product_id}
• CAS.ProductId EQ {product_id}

The characters making up the "CAS.ProductId" data element may be of any case and the {product_id} value may be any valid integer equaling the product identifier of an object residing in the Archive Service.

Specified by:

query in interface jpl.eda.product.QueryHandler

Parameters:

xmlQuery - The XMLQuery object containing the query.

Throws:

jpl.eda.product.ProductException - If the property is not set, the Archive Service cannot be accessed or the server returns an exception.

retrieveChunk

public byte[] retrieveChunk(java.lang.String id,
                            long offset,
                            int length)
                     throws jpl.eda.product.ProductException

Retrieve a fragment of the data from the specified file.

Specified by:

retrieveChunk in interface jpl.eda.product.LargeProductQueryHandler

Parameters:

id - The unique identifier for the file which is the archive reference.

offset - Skip into the file the specified number of bytes.

length - The number of bytes to read from the file.

Returns:

A fragment of the data in the file.

Throws:

jpl.eda.product.ProductException - If the server throws an exception.

close

public void close(java.lang.String id)
           throws jpl.eda.product.ProductException

Notify the server that a particular file transfer has completed.

Specified by:

close in interface jpl.eda.product.LargeProductQueryHandler

Parameters:

id - The unique identifier for the object.

Throws:

jpl.eda.product.ProductException - If the server throws an exception.

main

public static void main(java.lang.String[] argv)

Execute the large product handler.

The command-line arguments are as follows:

• serverName - The name of the Catalog and Archive Service. For example, "urn:eda:rmi:JPL.Test.Archive".
• keywordQuery - The query identifying a single product. For example, "CAS.ProductId = 1".

The program exits with status 0 on success, 1 on failure.

Properties specified inside the tag in the .edarc.xml file are not available when executed from the command-line. In this case default values are used and/or properties specified inside the main tag.

Ideally, from an actual client of the Product Service, the calling application should be able to call the LargeResult.getInputStream() method instead of calling the retrieveChunk() method and managing the transfer as it is done in this method. The former is simpler, but the later offers more control and possibly better exception handling.

Parameters:

argv - The command-line arguments.