Metacat

Metacat High Level API

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Multiple client interface
Since Metacat Servlet is a subclass of HttpServlet, this allows any client to communicate with Metacat by essentially passing a URL with embedded servlet parameters. Metacat Servlet provides an HTTP Interface and can handle GET and POST requests. HTTP requests are sent from the the Client application and contain a number of parameters. These parameters, in form of name/value pairs, provide input data for the Servlet and also provide the Servlet any extra information it needs to handle the request.

Extensions of HttpServlet
Metacat Server adds the functionality for writing, quering, and reading of XML stored in the Metacat Database as well functions for validating and transforming XML documents.

MetacatServlet Parameters

Action	Supplemental Parameters	Description
login	username - the user's login name password - the user's password	Log the user in.
logout	none	Log the current user out and destroy the associated session.
query	returndoctype - the doctype that you wish to use for your Package View qformat - the format that you wish to return the resultset in. Possible values are 'html' or 'xml'. querytitle - OPTIONAL - the title of the query doctype - OPTIONAL - if doctype is specified, the search is limited only to the doctype(s) specified. returnfield - a custom field to be returned by any hit document. This is explained in more detail in Queries and Results. operator - the boolean operator to apply to the query - Possible values are: UNION or INTERSECT searchmode - the type of search to be performed. Possible values are: contains, starts-with, ends-with, equals, isnot-equal, greater-than, less-than, greater-than-equals, less-than-equals. anyfield - a freetext search variable. A value placed in this parameter will be searched for in any document in any node.	Perform a free text query.
squery	query - the text of the pathquery document that is being sent to the server	Perform a structured query.
read	docid - the docid of the document to read qformat - the format to return the document in. Possible values are: html, xml	Get docid from the database and return it in qformat form.
insert	docid - the user defined docid to assign to the new XML document. doctext - the text of the XML document to insert	Insert an XML document into the database.
update	docid - the docid of the document to update doctext - the text with which to update the XML document	Overwrite an XML document with a new one and give the new one the same docid but with next revision number.
upload	docid - the docid of the data document to upload datafile - the data document to upload	Upload (insert or update) a data document into the database. Data files are stored on metacat and may be in any format (binary or text), but they are all treated as if they were binary. .
delete	docid - the docid of the document to delete	Delete the specified docid from the database.
validate	docid - the docid of the document to validate valtext - the DTD by which to validate this document	Validate docid against its DTD.
getaccesscontrol	docid - the docid of the document to get the ACL for	Get ACL for document with that docid
getprincipals	none	Get all users and groups in the current authentication schema
getdoctypes	none	Get all doctypes currently available in Metacat Catalog System.
getdtdschema	doctype - the doctype which DTD or XMLSchema file to read.	Read DTD or XMLSchema file for the specified doctype.
getdataguide	doctype - the doctype for which to get the data guide Deprecated. Use getdtdschema action instead.	Read a dataguide for doctype.
getlastdocid	username - the user's login name which last docid to get.	Get the latest docid with rev number used by user.
protocoltest	url - the url to test against the protocol handler	Test the protocol handlers installed for metacat:// URLs.
export	docid - the docid of the package you wish to export	Exports a data package in a zip file.

MetacatReplication Parameters

Action	Supplemental Parameters	Description
forcereplicate	server - The server to which this document is being sent docid - The docid of the document to send dbaction - DEFAULTS TO UPDATE - The action to perform on the document. INSERT or UPDATE.	Force this server to get docid from the remote host.
getall	none	Forces the local server to check all known servers for updated documents.
getcatalog	none	Sends the contents of the xml_catalog table encoded in XML.
getlock	docid - the docid to get the lock for updaterev - the revision number of docid	Request a lock on docid.
gettime	none	Return the local time on this server.
servercontrol	subaction - The replication control to be performed. Possible values: add - add a new server to the replication list delete - remove a server from the replication list list - list all of the servers currently in the server list replicate - a boolean flag (1 or 0) which determines if this server is to copy files from the newly added server. server - the server to add/delete	Perform subaction on the Replication daemon.
read	docid - the docid to read	Sends docid to the remote host.
start	rate - DEFAULTS TO 1000 - The rate (in seconds) at which you want the replication daemon to check for updated documents. The value cannot be less than 30.	Start the Replication daemon with a time interval of deltaT.
stop	none	Stop the Replication daemon.
update	none	Send a list of all documents on the local server along with their revision numbers.

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