how to print a byte to the console

[Roderik]

Hi,

I try to print a byte to the console. I like to print it in the
hexadeximal format. like
FF or something

How can I do this with System.out.println?

 

[Martin Honnen]

Roderik wrote:

I try to print a byte to the console. I like to print it in the
hexadeximal format. like
FF or something

How can I do this with System.out.println?

Try
Integer.toString(byteVariable, 16).toUpperCase()

 

[Roderik]

Roderik wrote:




Try
Integer.toString(byteVariable, 16).toUpperCase()

I tried:
System.out.println(Integer.toString(dis.readByte(), 16).toUpperCase());

which results in:
-1
12
-1
34
-1
56
-1
-56
-1
-44
3B
3

-1 should be FF. The only right output values are the last two bytes.

Any idea how I can output the bytes to the console the way a hex editor
would do.

 

[Michael Borgwardt]

I tried:
System.out.println(Integer.toString(dis.readByte(), 16).toUpperCase());

which results in:
-1 []
-1 should be FF. The only right output values are the last two bytes.

Try instead

System.out.println(Integer.toString(dis.readByte() & 0xff, 16).toUpperCase());

 

[Roderik]

I tried:
System.out.println(Integer.toString(dis.readByte(), 16).toUpperCase());

which results in:
-1
[]

-1 should be FF. The only right output values are the last two bytes.

Try instead

System.out.println(Integer.toString(dis.readByte() & 0xff,
16).toUpperCase());

Thanks, that works right.
Only, numbers below ten, like hexadecimal 03 are printed as 3 (without a
leading zero). Is there a standard function to change this or should I
make a conditional statement to add this 0 to the console output?

 

[Michael Borgwardt]

Only, numbers below ten, like hexadecimal 03 are printed as 3 (without a
leading zero). Is there a standard function to change this or should I
make a conditional statement to add this 0 to the console output?

Starting with Java 1.5 there is java.util.Formatter and String.format() that
are basically the analogue of C's printf(). They also do the hex conversion
for you. But if you're using an older Java version, you'll have to do the
zero padding yourself.

 

[Eric Sosman]

I tried:
System.out.println(Integer.toString(dis.readByte(), 16).toUpperCase());

which results in:
-1
12
-1
34
-1
56
-1
-56
-1
-44
3B
3

-1 should be FF. The only right output values are the last two bytes.

Why should negative one be two hundred fifty-five?
And why do you think a `byte' should be able to hold so
large a value, since its range goes from -128 through +127?
If you ponder this for a minute or two, I think you'll
solve at least part of your problem.

You've provided no means to study your claim that only
the final two values are "right," since you haven't shown a
sample of the input stream's data. Nor have you explained
what "rightness" is; from your -1 vs. FF confusion I'd have
guessed that the second, fourth, and sixth lines would also
be considered "right," but apparently you have some other
criterion in mind.

Any idea how I can output the bytes to the console the way a hex editor
would do.

I *had* an idea, but it wouldn't change the second, fourth,
or sixth lines -- and since these are "wrong," my idea probably
isn't what you're after. Sorry.

 

[Martin Honnen]

Roderik wrote:

System.out.println(Integer.toString(dis.readByte(), 16).toUpperCase());

which results in:
-1
12
-1
34
-1
56
-1
-56
-1
-44
3B
3

-1 should be FF. The only right output values are the last two bytes.

I think it is a sign issue, if you use

byte[] testBytes = new byte[] {
(byte) 1,
(byte) 2,
(byte) 4,
(byte) 8,
(byte) 16,
(byte) 32,
(byte) 64,
(byte) 128,
(byte) 255
};
for (int i = 0; i < testBytes.length; i++) {
System.out.println(Integer.toString(testBytes & 0xFF, 16));
}

then you should get the desired result.

 

[Jim]

Hi,

I try to print a byte to the console. I like to print it in the
hexadeximal format. like
FF or something

How can I do this with System.out.println?

Try the following

System.out.print(Integer.toHexString((i >= 0) ? i : 256 + i));

If you need two digit hex then

StringBuffer s =
new StringBuffer(Integer.toHexString((i >= 0) ? i : 256 + i));

if(s.length() == 1) s.insert(0,'0');


Jim

 

[pasquinelli]

Why should negative one be two hundred fifty-five?
And why do you think a `byte' should be able to hold so
large a value, since its range goes from -128 through +127?
If you ponder this for a minute or two, I think you'll
solve at least part of your problem.

You've provided no means to study your claim that only
the final two values are "right," since you haven't shown a
sample of the input stream's data. Nor have you explained
what "rightness" is; from your -1 vs. FF confusion I'd have
guessed that the second, fourth, and sixth lines would also
be considered "right," but apparently you have some other
criterion in mind.

--
(e-mail address removed)

i registered here just to tell you this:

learn to program.

-1 vs. FF confusion

:hahahaha:

i don't know how old this is, but i really hope you see this.