uk.ac.starlink.ecsv

Class EcsvDecoder<T>

java.lang.Object

uk.ac.starlink.ecsv.EcsvDecoder<T>

public abstract class EcsvDecoder<T>
extends java.lang.Object

Decodes values in the body of an ECSV file for a given data type.

Since:

28 Apr 2020

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	EcsvDecoder(java.lang.Class<T> clazz, int[] stilShape, java.lang.String msg) Constructor.

Method Summary

Modifier and Type	Method and Description
static EcsvDecoder<?>	createDecoder(java.lang.String datatype, java.lang.String subtype) Returns an instance of this class given a datatype and optional subtype.
abstract T	decode(java.lang.String txt) Attempts to decode the supplied string to a value of this decoder's type.
java.lang.Class<T>	getContentClass() Returns the class to which input values will be decoded.
int[]	getShape() Returns the shape of the object that is decoded, in STIL format.
java.lang.String	getWarning() Returns any warning message concerning the behaviour of this decoder.

Methods inherited from class java.lang.Object

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

Constructor Detail

EcsvDecoder

protected EcsvDecoder(java.lang.Class<T> clazz,
                      int[] stilShape,
                      java.lang.String msg)

Constructor.

Parameters:

clazz - destination class

stilShape - shape specifier in STIL format

msg - warning or diagnostic message concerning decoding, or null if everything is normal

Method Detail

decode

public abstract T decode(java.lang.String txt)

Attempts to decode the supplied string to a value of this decoder's type. The supplied string will not be null or the empty string. Implementations should work on the assumption that the supplied string is of an appropriate type for this decoder; if it is not, it is permissiable to throw a NumberFormatException.

Parameters:

txt - non-blank string to decode

Returns:

typed value

Throws:

java.lang.NumberFormatException - in case of unrecognised string

getContentClass

public java.lang.Class<T> getContentClass()

Returns the class to which input values will be decoded.

Returns:

destination class

getShape

public int[] getShape()

Returns the shape of the object that is decoded, in STIL format. That may not be the same as what was specified in the ECSV metadata, if STIL is not smart enough to make sense of it.

Returns:

STIL shape array, or null for scalar

getWarning

public java.lang.String getWarning()

Returns any warning message concerning the behaviour of this decoder.

Returns:

warning message to be conveyed to user concerning this column, or null if everything is normal

createDecoder

public static EcsvDecoder<?> createDecoder(java.lang.String datatype,
                                           java.lang.String subtype)

Returns an instance of this class given a datatype and optional subtype.

Parameters:

datatype - case-sensitive datatype name

subtype - subtype specifier string, or null

Returns:

decoder for datatype, or null if unknown or unsupported