Package uk.ac.starlink.vo
Class TapQuery
- java.lang.Object
-
- uk.ac.starlink.vo.TapQuery
-
public class TapQuery extends java.lang.Object
Represents a query to be made to a Table Access Protocol service. This class aggregates the information which needs to be sent to make such a query and provides methods to submit the query synchronously or asynchronously. It also contains some static methods to perform other TAP-related operations.- Since:
- 8 Apr 2011
- Author:
- Mark Taylor
- See Also:
- IVOA TAP Recommendation
-
-
Field Summary
Fields Modifier and Type Field Description static uk.ac.starlink.votable.DataFormat
DFLT_UPLOAD_SER
Default VOTable serialization format for uploading VOTables to a TAP service.
-
Constructor Summary
Constructors Constructor Description TapQuery(java.net.URL serviceUrl, java.lang.String adql, java.util.Map<java.lang.String,java.lang.String> extraParams)
Convenience constructor that uses a URL rather than an EndpointSet.TapQuery(EndpointSet endpointSet, java.lang.String adql, java.util.Map<java.lang.String,java.lang.String> extraParams)
Constructs a query with no uploaded tables.TapQuery(EndpointSet endpointSet, java.lang.String adql, java.util.Map<java.lang.String,java.lang.String> extraParams, java.util.Map<java.lang.String,uk.ac.starlink.table.StarTable> uploadMap, long uploadLimit, uk.ac.starlink.votable.VOTableWriter vowriter)
Constructs a query with uploaded tables.
-
Method Summary
All Methods Static Methods Instance Methods Concrete Methods Modifier and Type Method Description java.net.HttpURLConnection
createSyncConnection(uk.ac.starlink.util.ContentCoding coding)
Opens a URL connection for the result of synchronously executing this query.uk.ac.starlink.table.StarTable
executeSync(uk.ac.starlink.table.StoragePolicy storage, uk.ac.starlink.util.ContentCoding coding)
Executes this query synchronously and returns the resulting table.boolean
executeSync(uk.ac.starlink.table.TableSink sink, uk.ac.starlink.util.ContentCoding coding)
Executes this query synchronously and streams the resulting table to a table sink.static java.net.URLConnection
followRedirects(java.net.URLConnection conn)
Takes a URLConnection and repeatedly follows 303 redirects until a non-303 status is achieved.java.lang.String
getAdql()
Returns the text of the ADQL query for this object.EndpointSet
getEndpointSet()
Returns the endpoints of TAP services to which this query will be submitted.static uk.ac.starlink.table.StarTable
getResult(UwsJob uwsJob, uk.ac.starlink.util.ContentCoding coding, uk.ac.starlink.table.StoragePolicy storage)
Reads and returns the table that resulted from a successful TAP query, represented by a given UWS job.java.util.Map<java.lang.String,HttpStreamParam>
getStreamParams()
Returns the map of streamed parameters to be passed to the TAP service.java.util.Map<java.lang.String,java.lang.String>
getStringParams()
Returns the map of string parameters to be passed to the TAP service.static java.io.InputStream
getVOTableStream(java.net.URLConnection conn, uk.ac.starlink.util.ContentCoding coding)
Gets an input stream from a URL connection that should contain a VOTable.static uk.ac.starlink.table.StarTable
readResultVOTable(java.net.URLConnection conn, uk.ac.starlink.util.ContentCoding coding, uk.ac.starlink.table.StoragePolicy storage)
Reads a VOTable which may represent a successful result or an error.static <T> T
scalarQuery(EndpointSet endpointSet, java.lang.String adql, java.lang.Class<T> clazz)
Utility method to obtain a single-cell table as the result of a synchronous TAP query.static boolean
streamResultVOTable(java.net.URLConnection conn, uk.ac.starlink.util.ContentCoding coding, uk.ac.starlink.table.TableSink sink)
Streams a VOTable document which may represent a successful result or an error.UwsJob
submitAsync()
Submits this query asynchronously and returns the corresponding UWS job.static uk.ac.starlink.table.StarTable
waitForResult(UwsJob uwsJob, uk.ac.starlink.util.ContentCoding coding, uk.ac.starlink.table.StoragePolicy storage, long pollMillis)
Blocks until the TAP query represented by a given UWS job has completed, then returns a table based on the result.static java.net.URL
waitForResultUrl(UwsJob uwsJob, long pollMillis)
Blocks until the TAP query represented by a given UWS job has completed, then returns the URL from which the successful result can be obtained.
-
-
-
Field Detail
-
DFLT_UPLOAD_SER
public static final uk.ac.starlink.votable.DataFormat DFLT_UPLOAD_SER
Default VOTable serialization format for uploading VOTables to a TAP service. The value is currentlyDataFormat.TABLEDATA
. BINARY would be more efficient and ought to be OK, but at time of writing at least CADC, and under some circumstances other services, work properly with TABLEDATA but not BINARY uploaded tables, so for now conform to the lowest common denominator.
-
-
Constructor Detail
-
TapQuery
public TapQuery(EndpointSet endpointSet, java.lang.String adql, java.util.Map<java.lang.String,java.lang.String> extraParams)
Constructs a query with no uploaded tables.- Parameters:
endpointSet
- locations of TAP service endpointsadql
- text of ADQL queryextraParams
- key->value map for optional parameters; if any of these match the names of standard parameters (upper case) the standard values will be overwritten, so use with care (may be null)
-
TapQuery
public TapQuery(EndpointSet endpointSet, java.lang.String adql, java.util.Map<java.lang.String,java.lang.String> extraParams, java.util.Map<java.lang.String,uk.ac.starlink.table.StarTable> uploadMap, long uploadLimit, uk.ac.starlink.votable.VOTableWriter vowriter) throws java.io.IOException
Constructs a query with uploaded tables. May throw an IOException if the tables specified for upload exceed the stated upload limit.- Parameters:
endpointSet
- locations of TAP service endpointsadql
- text of ADQL queryextraParams
- key->value map for optional parameters; if any of these match the names of standard parameters (upper case) the standard values will be overwritten, so use with care (may be null)uploadMap
- name->table map of tables to be uploaded to the service for the query (may be null)uploadLimit
- maximum number of bytes that may be uploaded; if negative, no limit is applied, ignored ifuploadMap
null or emptyvowriter
- serializer for producing content of uploaded tables; ignored ifuploadMap
null or empty, if null a default value is used- Throws:
java.io.IOException
- if upload tables exceed the upload limit
-
TapQuery
public TapQuery(java.net.URL serviceUrl, java.lang.String adql, java.util.Map<java.lang.String,java.lang.String> extraParams)
Convenience constructor that uses a URL rather than an EndpointSet. This just usesEndpoints.createDefaultTapEndpointSet(java.lang.String)
and then invokes one of the other constructors.This form is mildly deprecated, it is preferred to create your own EndpointSet as above and submit that to one of the other constructors instead. It's present because other classes rely on it, but there is no intention to add URL-based constructors corresponding to the other EndpointSet-based forms.
- Parameters:
serviceUrl
- base URL of TAP serviceadql
- text of ADQL queryextraParams
- key->value map for optional parameters; if any of these match the names of standard parameters (upper case) the standard values will be overwritten, so use with care (may be null)
-
-
Method Detail
-
getAdql
public java.lang.String getAdql()
Returns the text of the ADQL query for this object.- Returns:
- ADQL query text
-
getEndpointSet
public EndpointSet getEndpointSet()
Returns the endpoints of TAP services to which this query will be submitted.- Returns:
- service locations
-
getStringParams
public java.util.Map<java.lang.String,java.lang.String> getStringParams()
Returns the map of string parameters to be passed to the TAP service.- Returns:
- name->value map for TAP string parameters
-
getStreamParams
public java.util.Map<java.lang.String,HttpStreamParam> getStreamParams()
Returns the map of streamed parameters to be passed to the TAP service.- Returns:
- name->value map for TAP stream parameters
-
executeSync
public uk.ac.starlink.table.StarTable executeSync(uk.ac.starlink.table.StoragePolicy storage, uk.ac.starlink.util.ContentCoding coding) throws java.io.IOException
Executes this query synchronously and returns the resulting table.- Parameters:
storage
- storage policy for caching table datacoding
- configures HTTP compression- Returns:
- result table
- Throws:
java.io.IOException
-
executeSync
public boolean executeSync(uk.ac.starlink.table.TableSink sink, uk.ac.starlink.util.ContentCoding coding) throws java.io.IOException, org.xml.sax.SAXException
Executes this query synchronously and streams the resulting table to a table sink. If the result is a TAP error document, it will be presented as an exception thrown from this method. Overflow status of a successful result is provided by the return value.- Parameters:
sink
- table destinationcoding
- configures HTTP compression- Returns:
- true iff the result was marked as overflowed
- Throws:
java.io.IOException
org.xml.sax.SAXException
-
createSyncConnection
public java.net.HttpURLConnection createSyncConnection(uk.ac.starlink.util.ContentCoding coding) throws java.io.IOException
Opens a URL connection for the result of synchronously executing this query.- Parameters:
coding
- HTTP content-coding policy result should be interpreted with same coding- Returns:
- HTTP connection containing query result
- Throws:
java.io.IOException
-
submitAsync
public UwsJob submitAsync() throws java.io.IOException
Submits this query asynchronously and returns the corresponding UWS job. The job is not started.- Returns:
- new UWS job for this query
- Throws:
java.io.IOException
-
waitForResultUrl
public static java.net.URL waitForResultUrl(UwsJob uwsJob, long pollMillis) throws java.io.IOException, java.lang.InterruptedException
Blocks until the TAP query represented by a given UWS job has completed, then returns the URL from which the successful result can be obtained. If the job does not complete successfully, an IOException is thrown instead.- Parameters:
uwsJob
- started UWS job representing an async TAP querypollMillis
- polling interval in milliseconds- Returns:
- open URL connection to result stream
- Throws:
java.io.IOException
java.lang.InterruptedException
-
waitForResult
public static uk.ac.starlink.table.StarTable waitForResult(UwsJob uwsJob, uk.ac.starlink.util.ContentCoding coding, uk.ac.starlink.table.StoragePolicy storage, long pollMillis) throws java.io.IOException, java.lang.InterruptedException
Blocks until the TAP query represented by a given UWS job has completed, then returns a table based on the result. In case of job failure, an exception will be thrown instead.- Parameters:
uwsJob
- started UWS job representing an async TAP querycoding
- configures HTTP compressionstorage
- storage policy for caching table datapollMillis
- polling interval in milliseconds- Returns:
- result table
- Throws:
java.io.IOException
java.lang.InterruptedException
-
getResult
public static uk.ac.starlink.table.StarTable getResult(UwsJob uwsJob, uk.ac.starlink.util.ContentCoding coding, uk.ac.starlink.table.StoragePolicy storage) throws java.io.IOException
Reads and returns the table that resulted from a successful TAP query, represented by a given UWS job. The query is assumed to have requested output in VOTable format. If the job has not reached COMPLETED phase, an IOException will result.- Parameters:
uwsJob
- successfully completed UWS job representing an async TAP querycoding
- configures HTTP compressionstorage
- storage policy for caching table data- Returns:
- the result of reading the TAP result as a table
- Throws:
java.io.IOException
-
scalarQuery
public static <T> T scalarQuery(EndpointSet endpointSet, java.lang.String adql, java.lang.Class<T> clazz) throws java.io.IOException
Utility method to obtain a single-cell table as the result of a synchronous TAP query.- Parameters:
endpointSet
- locations of TAP servicesadql
- query stringclazz
- class of required value- Returns:
- single value, or null if no rows
- Throws:
java.io.IOException
- if required result cannot be got
-
readResultVOTable
public static uk.ac.starlink.table.StarTable readResultVOTable(java.net.URLConnection conn, uk.ac.starlink.util.ContentCoding coding, uk.ac.starlink.table.StoragePolicy storage) throws java.io.IOException
Reads a VOTable which may represent a successful result or an error. If it represents an error (in accordance with the TAP rules for expressing this), an exception will be thrown.- Parameters:
conn
- connection to table resourcecoding
- HTTP content coding policy used to prepare connectionstorage
- storage policy- Returns:
- table result of successful query
- Throws:
java.io.IOException
-
streamResultVOTable
public static boolean streamResultVOTable(java.net.URLConnection conn, uk.ac.starlink.util.ContentCoding coding, uk.ac.starlink.table.TableSink sink) throws java.io.IOException, org.xml.sax.SAXException
Streams a VOTable document which may represent a successful result or an error. If it represents an error (in accordance with the TAP rules for expressing this), an exception will be thrown. Overflow status of a successful result is provided by the return value.Note: any XML that comes after the TABLE element of the result table is ignored for the purposes of reporting the table metadata. The only thing after the end of the TABLE that affects the result of this method is the overflow flag, which affects the return value. So if you need to pick up items which might be in trailing elements, for instance Service Descriptors in later RESOURCE elements, you will have to use a different method.
- Parameters:
conn
- connection to table resourcecoding
- HTTP content coding policy used to prepare connectionsink
- destination for table result of succesful query- Returns:
- true iff the result was marked as overflowed
- Throws:
java.io.IOException
org.xml.sax.SAXException
-
getVOTableStream
public static java.io.InputStream getVOTableStream(java.net.URLConnection conn, uk.ac.starlink.util.ContentCoding coding) throws java.io.IOException
Gets an input stream from a URL connection that should contain a VOTable.- Parameters:
conn
- connection to result of TAP service callcoding
- HTTP content coding policy used to prepare connection- Returns:
- stream containing a response table (error or result)
- Throws:
java.io.IOException
-
followRedirects
public static java.net.URLConnection followRedirects(java.net.URLConnection conn) throws java.io.IOException
Takes a URLConnection and repeatedly follows 303 redirects until a non-303 status is achieved. Infinite loops are defended against. The Accept-Encoding header, if present, is propagated to redirect targets.- Parameters:
conn
- initial URL connection- Returns:
- target URL connection
(if no redirects, the same as
hconn
) - Throws:
java.io.IOException
-
-