Package io.bytestreams.codec.core

Class FixedListCodec<V>

java.lang.Object

io.bytestreams.codec.core.FixedListCodec<V>

Type Parameters:

V - the type of values in the list

All Implemented Interfaces:

Codec<List<V>>, Inspectable<List<V>>

public class FixedListCodec<V>
extends Object
implements Codec<List<V>>, Inspectable<List<V>>

A codec for encoding and decoding fixed-length lists of values.

This codec encodes and decodes exactly length items. Unlike StreamListCodec, which reads items until EOF, this codec reads a fixed number of items from the stream.

Example usage:

 // Decode exactly 3 items
 Codec<List<String>> codec = Codecs.listOf(3, Codecs.ascii(5));
 codec.encode(List.of("hello", "world", "abcde"), output);
 List<String> values = codec.decode(input);
 

Constructor Summary

Constructors

Constructor	Description
FixedListCodec(Codec<V> itemCodec, int length)	Creates a new fixed list codec that uses ArrayList for decoded lists.
FixedListCodec(Codec<V> itemCodec, int length, Supplier<List<V>> listFactory)	Creates a new fixed list codec with a custom list factory.

Method Summary

Modifier and Type	Method	Description
List<V>	decode(InputStream input)	Decodes a value from the input stream.
EncodeResult	encode(List<V> values, OutputStream output)	Encodes the given value and writes it to the output stream.
Object	inspect(List<V> values)	Returns a structured representation of the given value.

Methods inherited from class java.lang.Object

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

Methods inherited from interface io.bytestreams.codec.core.Codec

xmap, xmap

Constructor Details

FixedListCodec

public FixedListCodec(Codec<V> itemCodec,
 int length)

Creates a new fixed list codec that uses ArrayList for decoded lists.

Parameters:

itemCodec - the codec for encoding/decoding individual list items

length - the exact number of items to encode/decode (must be non-negative)

Throws:

NullPointerException - if itemCodec is null

IllegalArgumentException - if length is negative

FixedListCodec

public FixedListCodec(Codec<V> itemCodec,
 int length,
 Supplier<List<V>> listFactory)

Creates a new fixed list codec with a custom list factory.

Parameters:

itemCodec - the codec for encoding/decoding individual list items

length - the exact number of items to encode/decode (must be non-negative)

listFactory - a factory that creates new list instances for decoding

Throws:

NullPointerException - if any argument is null

IllegalArgumentException - if length is negative

Method Details

encode

public EncodeResult encode(List<V> values,
 OutputStream output)
                    throws IOException

Encodes the given value and writes it to the output stream.

Encodes each item in the list sequentially using the item codec.

Specified by:

encode in interface Codec<V>

Parameters:

values - the value to encode

output - the output stream to write the encoded bytes to

Returns:

the encode result containing logical count and bytes written

Throws:

IllegalArgumentException - if the list size does not equal length

IOException - if an I/O error occurs during encoding

decode

public List<V> decode(InputStream input)
               throws IOException

Decodes a value from the input stream.

Decodes exactly length items from the stream.

Specified by:

decode in interface Codec<V>

Parameters:

input - the input stream to read the encoded bytes from

Returns:

the decoded value

Throws:

EOFException - if the stream ends before all items are read

IOException - if an I/O error occurs during decoding

inspect

public Object inspect(List<V> values)

Description copied from interface: Inspectable

Returns a structured representation of the given value.

Specified by:

inspect in interface Inspectable<V>

Parameters:

values - the decoded value to inspect

Returns:

a structured representation (Map, List, or scalar)