select
Finds the first byte string in options that is a prefix of this buffer, consumes it from this source, and returns its index. If no byte string in options is a prefix of this buffer this returns -1 and no bytes are consumed.
This can be used as an alternative to readByteString or even readUtf8 if the set of expected values is known in advance.
Options FIELDS = Options.of(
ByteString.encodeUtf8("depth="),
ByteString.encodeUtf8("height="),
ByteString.encodeUtf8("width="));
Buffer buffer = new Buffer()
.writeUtf8("width=640\n")
.writeUtf8("height=480\n");
assertEquals(2, buffer.select(FIELDS));
assertEquals(640, buffer.readDecimalLong());
assertEquals('\n', buffer.readByte());
assertEquals(1, buffer.select(FIELDS));
assertEquals(480, buffer.readDecimalLong());
assertEquals('\n', buffer.readByte());Content copied to clipboard
Finds the first item in options whose encoding is a prefix of this buffer, consumes it from this buffer, and returns it. If no item in options is a prefix of this source, this function returns null and no bytes are consumed.
This can be used as an alternative to readByteString or even readUtf8 if the set of expected values is known in advance.
TypedOptions<Direction> options = TypedOptions.of(
Arrays.asList(Direction.values()),
(direction) -> ByteString.encodeUtf8(direction.name().toLowerCase(Locale.ROOT))
);
Buffer buffer = new Buffer()
.writeUtf8("north:100\n")
.writeUtf8("east:50\n");
assertEquals(Direction.NORTH, buffer.select(options));
assertEquals(':', buffer.readByte());
assertEquals(100L, buffer.readDecimalLong());
assertEquals('\n', buffer.readByte());
assertEquals(Direction.EAST, buffer.select(options));
assertEquals(':', buffer.readByte());
assertEquals(50L, buffer.readDecimalLong());
assertEquals('\n', buffer.readByte());Content copied to clipboard