stsci.client
Class ArchiveClient

java.lang.Object
  |
  +--stsci.client.ArchiveClient

public class ArchiveClient

extends java.lang.Object

This hides the implemnentation of ArchiveServer even more from the client code. Depending on the REMOTE property a local ArchiveServerImpl is created or an RMI version is requested from the server. The client keeps track of which archives have been loaded - client code should use getArchive from this class rather than calling directly from the ArchiveDescriptor.

Field Summary

protected Archive[]	archives
protected ArchiveDescriptor[]	descriptors
protected static ArchiveClient	theClient

Constructor Summary

protected

ArchiveClient() Protected constructor - this is a singleton, use getArchiveClient to get the single instance.

Method Summary

int	countArchives() Number of archive descriptors the client got from the ArchiveServer.
Archive	getArchive(int num) Get the numbered archive where the number is zero offset in the list of returned archives from listArchives.
Archive	getArchive(java.lang.String name) Get the archive of the given name.
static ArchiveClient	getArchiveClient() This is a singleton use this method to get the instance.
static ArchiveServer	getArchiveServer() This get the archive server implementaion.
ArchiveDescriptor	getDescriptor(int num) Get the ArchiveDescriptor at the numbered position.

Methods inherited from class java.lang.Object

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

Field Detail

descriptors

protected ArchiveDescriptor[] descriptors

theClient

protected static ArchiveClient theClient

archives

protected Archive[] archives

Constructor Detail

ArchiveClient

protected ArchiveClient()

Protected constructor - this is a singleton, use getArchiveClient to get the single instance. When its constructed it contacts the ArchiveServer once to get the list of Descriptors.

Method Detail

getArchive

public Archive getArchive(java.lang.String name)
                   throws NotFoundException

Get the archive of the given name. Uses the other getArchive with a number once it locates the named archive. Only implemented a simple linear search since there will never be that many archives that this would be too slow. Also the client is more likely to request the whole list of Archives and then work with the numbers.

getArchive

public Archive getArchive(int num)
                   throws NotFoundException

Get the numbered archive where the number is zero offset in the list of returned archives from listArchives. The client actually keeps track of which archives have been requested and does not construct new archives unless it needs to. Hence client code can always come back here to get a handle on an archive and it will get the same archive not a new instance.

getArchiveClient

public static ArchiveClient getArchiveClient()

This is a singleton use this method to get the instance.

countArchives

public int countArchives()

Number of archive descriptors the client got from the ArchiveServer.

getDescriptor

public ArchiveDescriptor getDescriptor(int num)
                                throws NotFoundException

Get the ArchiveDescriptor at the numbered position. This is needed to get names and information about the archives without actually constructing them. The CatalogPanel uses this for example to construct the menu of available archives.

getArchiveServer

public static ArchiveServer getArchiveServer()

This get the archive server implementaion. If REMOTE is yes it goes to the specified RMI sercer to pick up the ArchiveServer. Otherwise it constructs an ArchiveServerImpl locally. This does mean the Server code needs to be on the client machine but since the object is constructed from its String name there is no actual dependancy on it - hence the client code can be shiped without the server class and it will work using REMOTE="yes" however if the ArchiveServerImpl code is available you may sepcify REMOTE="no" and this will work also.