uk.ac.starlink.hapi

Class HapiTableReader

java.lang.Object

uk.ac.starlink.hapi.HapiTableReader

public class HapiTableReader
extends java.lang.Object

Converts HAPI metadata and input streams to StarTables.

Since:

12 Jan 2024

Constructor Summary

Constructors

Constructor and Description
HapiTableReader(HapiParam[] params) Constructor.

Method Summary

Modifier and Type	Method and Description
RowSequence	createRowSequence(java.io.InputStream in, java.lang.Byte byte0, java.lang.String fmt) Returns a row sequence given a HAPI data stream with no header.
RowSequence	createRowSequenceUsingHeader(java.io.InputStream in) Returns a row sequence given a HAPI data stream including the prepended commented header (info JSON object) information.
StarTable	createStarTable(IOSupplier<RowSequence> rseqSupplier) Produces a StarTable based on this metadata given a source of row sequence data.

Methods inherited from class java.lang.Object

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

Constructor Detail

HapiTableReader

public HapiTableReader(HapiParam[] params)

Constructor.

Parameters:

params - array of parameters that will be read

Method Detail

createStarTable

public StarTable createStarTable(IOSupplier<RowSequence> rseqSupplier)

Produces a StarTable based on this metadata given a source of row sequence data. This may be obtained using other methods of this class.

If a null RowSequence supplier is provided, the resulting table will be data-less; its metadata methods will work, but attempts to read its data will fail.

Parameters:

rseqSupplier - provides sequential data for the table, or null

Returns:

table

createRowSequenceUsingHeader

public RowSequence createRowSequenceUsingHeader(java.io.InputStream in)
                                         throws java.io.IOException

Returns a row sequence given a HAPI data stream including the prepended commented header (info JSON object) information. The header is used to determine the serialization format, though not the table metadata, of the data part of the input stream.

The supplied input stream will be used as is, so any buffering should be applied before calling this method.

Parameters:

in - input stream including prepended HAPI header

Returns:

row sequence

Throws:

java.io.IOException

createRowSequence

public RowSequence createRowSequence(java.io.InputStream in,
                                     java.lang.Byte byte0,
                                     java.lang.String fmt)
                              throws java.io.IOException

Returns a row sequence given a HAPI data stream with no header. The first byte may optionally be supplied separately.

The supplied input stream will be used as is, so any buffering should be applied before calling this method.

Parameters:

in - input stream ready for use

byte0 - byte to read at start of input sequence, or null

fmt - data stream format, one of "csv" or "binary"

Returns:

row sequence

Throws:

java.io.IOException