uk.ac.starlink.vo

Class TapSchemaTapMetaReader

java.lang.Object

uk.ac.starlink.vo.TapSchemaTapMetaReader

All Implemented Interfaces:

TapMetaReader

public class TapSchemaTapMetaReader
extends Object
implements TapMetaReader

TapMetaReader implementation that uses TAP queries on the TAP_SCHEMA schema to acquire table metadata.

Since:

18 Mar 2015

Author:

Mark Taylor

Constructor Summary

Constructors

Constructor and Description
TapSchemaTapMetaReader(TapService service, int maxrec, ContentCoding coding, boolean populateSchemas, boolean populateTables, MetaNameFixer fixer, boolean preloadFkeys) Constructor.

Method Summary

Modifier and Type	Method and Description
String	getMeans() Returns a textual indication of the method or protocol this reader uses to acquire TAP metadata.
String	getSource() Returns a textual indication of where the metadata is coming from, typically a URL.
ColumnMeta[]	readColumns(TableMeta table) Acquires metadata about columns in a given table from a TAP service.
ForeignMeta[]	readForeignKeys(TableMeta table) Acquires metadata about foreign keys in a given table from a TAP service.
SchemaMeta[]	readSchemas() Acquires metadata about schemas in a TAP service.
TableMeta[]	readTables(SchemaMeta schema) Acquires metadata about tables in a given schema from a TAP service.

Methods inherited from class java.lang.Object

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

Constructor Detail

TapSchemaTapMetaReader

public TapSchemaTapMetaReader(TapService service,
                              int maxrec,
                              ContentCoding coding,
                              boolean populateSchemas,
                              boolean populateTables,
                              MetaNameFixer fixer,
                              boolean preloadFkeys)

Constructor.

Parameters:

service - TAP service description

maxrec - maximum number of records to be requested at once

coding - configures HTTP compression

populateSchemas - whether SchemaMeta objects will be filled in with table lists when they are acquired

populateTables - whether TableMeta objects will be filled in with column and foreign key lists when they are acquired

fixer - object that fixes up syntactically incorrect table/column names; if null no fixing is done; has no effect for compliant TAP_SCHEMA services

preloadFkeys - if true, all foreign key info is loaded in one go, if false it's read per-table as required

Method Detail

getSource

public String getSource()

Description copied from interface: TapMetaReader

Returns a textual indication of where the metadata is coming from, typically a URL.

Specified by:

getSource in interface TapMetaReader

Returns:

address of metadata

getMeans

public String getMeans()

Description copied from interface: TapMetaReader

Returns a textual indication of the method or protocol this reader uses to acquire TAP metadata.

Specified by:

getMeans in interface TapMetaReader

Returns:

short description of metadata acquisition method

readSchemas

public SchemaMeta[] readSchemas()
                         throws IOException

Description copied from interface: TapMetaReader

Acquires metadata about schemas in a TAP service.

May be slow.

Specified by:

readSchemas in interface TapMetaReader

Returns:

schema metadata array

Throws:

IOException

readTables

public TableMeta[] readTables(SchemaMeta schema)
                       throws IOException

Description copied from interface: TapMetaReader

Acquires metadata about tables in a given schema from a TAP service.

May be slow. May throw UnsupportedOperationException if not needed.

Specified by:

readTables in interface TapMetaReader

Parameters:

schema - schema containing tables; not altered by call

Returns:

table metadata array

Throws:

IOException

readColumns

public ColumnMeta[] readColumns(TableMeta table)
                         throws IOException

Description copied from interface: TapMetaReader

Acquires metadata about columns in a given table from a TAP service.

May be slow. May throw UnsupportedOperationException if not needed.

Specified by:

readColumns in interface TapMetaReader

Parameters:

table - table containing columns; not altered by call

Returns:

column metadata array

Throws:

IOException

readForeignKeys

public ForeignMeta[] readForeignKeys(TableMeta table)
                              throws IOException

Description copied from interface: TapMetaReader

Acquires metadata about foreign keys in a given table from a TAP service.

May be slow. May throw UnsupportedOperationException if not needed.

Specified by:

readForeignKeys in interface TapMetaReader

Parameters:

table - table containing columns; not altered by call

Returns:

foreign key metadata array

Throws:

IOException