CODEWITHSUNDEEP
java
user547453
user547453

Reputation: 1045

Java - bytes and binary

This is a basic question.

When I use a byte stream to write bytes to a file, am I creating a binary file?

For example: I use a byte stream to write text data to a notepad and when I open the notepad in a HEX viewer I see the corresponding hex value for each character. But why not the binary values (i.e 0s and 1s).

I also learned that using a dataoutput/input stream I read/write binary file.

I guess my confusion is with what does it mean to write bytes and what does it mean to write a binary data.

Upvotes: 5

Views: 546

Answers (4)

Johan Sjöberg
Johan Sjöberg

Reputation: 49177

When I use a byte stream to write bytes to a file, am I creating a binary file?

You write the bytes as is, e.g., as the ones and zeroes they are. If these bytes represents characters then commonly no, it's just a text-file (everything is ones and zeroes after all). Otherwise the answers is it depends. The term binary file is missleading, but is usually referers to as a file which can contain arbitrary data.

when I open the notepad in a HEX viewer I see the corresponding hex value for each character. But why not the binary values

HEX is just another representation of bytes. The following three are equal

10       (Decimal value 10)
0xA      (Hex value 10)
00001010 (Binary value 10)

A computer only stores binary values. But editors may choose to represent (display) those in another way, such as Hex or decimal form. Given enough bytes, it can even be represented as an image.

what does it mean to write bytes and what does it mean to write a binary data

Binary data means ones and zeroes, e.g., 00001010 which are 8 bits. 8 bits makes a byte.

Upvotes: 4

Tadas S
Tadas S

Reputation: 1963

Typically you are create a text file using Writer(s), and a binary file using other means (Streams, Channels, etc.). However, if your 'binary' file contains text and only text, it is a text file regardless.

Regarding hexadecimal format, that is merely a compact (preferred) way of viewing byte values.

Upvotes: 1

David W
David W

Reputation: 10184

The notions of "text" and "binary" files is mostly a notional understanding for you and me as "consumers" of the file. Strictly speaking, every file consists of 1's and 0's, and are thus all binary in the truest sense of the word. Hexadecimal representations, encodings for a particular character set, image file formats. You can spin up an array of 100 random bytes, spit it out to a file, and it's just as "binary" as any other file. Its all in the context of how the bytes are interpreted that makes the difference.

Here's an example. In old tried-and-true ACII, an upper-case "A" is encoded as decimal 65. You can represent that to people as 0x41 (hex) in a hex viewer, as an "A" an editor, but ultimately, you write that byte to a file, it's just a byte translated to a series of eight bits, 01000001.

Upvotes: 1

Damian Leszczyński - Vash
Damian Leszczyński - Vash

Reputation: 30865

The confusion could be caused by the application you are using. If you open something in HEX viewer, it should be represented in HEX not BIN.

Upvotes: 1

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