byte 3 « byte « Java Data Type Q&A

1. Litle question about bytes..

2. changing of byte value

3. facing bytes problem

i have a program where a user keys in a hex string, and the computer outputs the byte value in dec format. example - user keys in 51. output - 81 i convert the string to byte using parseByte(xx, 16) the problem i am facing now is, the max value the user can key in is 7f. anything 80 and above ...

4. Efficiency with bytes

I am making a program which needs to take simple binary sprites and draw them in a window. If a bit is set, then it sets the pixel, if not, it doesn't. The real trouble is that I'm unsure of how to do this efficiently. I'm convinced there is a better way than having a series of if-then statements, but really, ...

5. Byte calculator and simulator

in java i send to server following byte value, it return Cid value, what exactly or how calculation is done ( 0x1 = 5 , 0x2 = 13 ? or 0x1 + 0x2 = 513?) ? The call id a user definable value that will be used on all status report. bit[3] = 0x1 bit[4] = 0x2 output: Cid=513 bit[3] = ...

6. byte to string

7. string --> byte

8. byte to string

9. byte[] from base 16

When I compute digests I get byte[] and store them into a Vector. But I must compare all of them with an already transformed into a hex string byte[] digest. If I would convert all the byte[] to hex string it would be too cpu intensive. Thats why I asked for an advice to convert that hex string to a byte[]. ...

10. Writing Bytes

11. byte[] to text

The overall picture is this: the input is a plain-text password that must be hashed x number of times. The hashed password needs to be entered by the user to log into a system, so it needs to be converted back to some non-byte form for the user to enter it - so basically back to the pre-hashed state (i don't ...

12. when to use byte

Is it really worth to use primitive datatypes like byte and short over int, when arithmetic is used? I've read that byte and short are converted to int prior to arithmetic and it just seems cumbersome when some of your bytes/shorts mingle with ints. When do people actually use these datatypes other than memory critical apps? thanks

14. byte mathematic operation

Hi I was going through the SCJP mock exam. where i came across the following question. Consider the following line of code: byte x=64; byte y=5; byte z= (byte)(x*y); After execution what is value of z? The answer that got printed was 64. Can anyone please help me to know how this answer came Thanks in advance.

15. Getting a binary/ocal/hexadecimal string and retrieving a byte[]

Hey guys, I could not find anything on Java API a class where I can parse a string (0b, 0o, 0x) and getting back a byte array. Do your guys have an idea? I know that we can use Long, Integer, etc... to do that, but they retrieve other objects but a byte array. ps: The string can containing the binary/ocatal/hexa ...

16. constructing JarInputStream from byte[]

one jar in one datagram packet in general won't work. The question is why do you want to use UDP? (This isn't an accusatory question, but an honest one). Could you perhaps just broadcast the tcp address of where the jar files should be fetched from using UDP, and let the clients grab the jar thru tcp?

17. Byte Combining

Hi, How do you go about combining bytes in the same way that you would add integers together? I have been writing audio software, and I want to combine two byte arrays (in which wav files are stored) before outputting them to the audio line, but I'm not sure if byte a + byte b is correct... Cheers, Crispin

18. writing bytes

19. byte return

20. logical OR for three bytes

actually to read data from device i should send request. The sending request is logical OR of three bytes TA1 , TA2 and TA3. TA1 and TA2 is the starting address which is equal to 0x1000 and TA3 is 0x82. there fore the logical OR of these these bytes TA1- 0x00 TA2- 0x10 TA3- 0x82 is 0x92. On sending this 0x92 ...

21. String & byte

Hello everybody, I'm in this situation: I have a byte array initialized by a list of integers. For some reason, my goal is to convert it to a String and then to get those integers. I wrote this simple code: byte b[] = { -38, -127, -53, -52, 87, 40, -50, -44, -53, 87, -56, -52, 63, 81, 0, -56, 76, ...

22. Byte I/O

Hi, I have a file (e.g. binary.txt) . I want to use FileInputStream and FileOutputStream to do the I/O. For the input read, I want to read in the binary data from the file into a byte[] and return it. For the output write, I want to write byte[] data to the file. Is there any sample codes for me to ...

23. concatting bytes

It's the values. -10 has a bunch of 1's on the left. So anything OR'ed with it will still be a bunch of 1's, and thus you end up with -10. I suppose the solution would be to AND the non-shifted value with 0xff, and then OR the result to the shifted valued. I suspect that printing out the values with ...

24. byte b = 0x00 | 0x80 gets loss of precision?

25. byte type

I was reading the previous post about java virous and Regards to that I found this : " I was thinking the only difference between the byte and int java type is that byte uses less memory That is roughly correct. Both byte and int are signed integer datatypes, but byte uses 1 byte while int uses 4 bytes. There are ...

26. decompressing byte[]

27. Loading a jpg from a byte[]

Hi, I am trying to load a jpg image from the internet into an array of pixel data or similar format. I am loading the image using Apache's HttpClient, but I don't know how to get the data into a form where I can get the pixel data. I will be trying to find the darkest/lightest spots on the image, as ...

28. output byte arr as string

It looks like you're taking each byte from the array, getting it's String representation (which is in decimal by the way), then parsing that String as a hex number. That doesn't really make sense, if you want to append the hex representation of each byte to the string, then just use Integer.toHexString(int).

29. How to count bytes number in a string?

Thanks Darry, but the problem persists in sense that my aim is to create a generic api, then I cannot know which encoding the user will use... I can do some assumptions about the encoding (utf-8 utf-16 and others....) but they reamain only attempts.... the exact encoding will remain a mystery for me....and then my getBytes(some encoding) will remain a precarius ...

31. cache byte[]

Hi , I wanna save a byte array byte [] on a Hashtable. The byte array is a DatagramPacket capture. If I receive a request matching the saved byte array , I wanna get the DatagramPacket from the Hashtable. But I have Object to byte[] convertion trouble ... Who can help please. Thanks,

32. HTML tag and src attribute as a byte[]

IE doesn't support data: URI's. What do you mean custom tags? Is this HTML to a browser or XML that you are going to parse? If the latter, you should still encode the bytes as base64 or some similar encoding, otherwise you don't know what's in the data that could muck with the XML parsing. In which case, typically, I'd define ...

33. SecretKey from byte[]

34. I cant add two byte variable

35. Probelm when receiving bytes

Hi I have a problem when working with networking, my problem is not really about networking but about the codification of bytes. The client is on pocketbuilder and is sending me in "ansi" a number, I am receving here each number in two bytes. How can I transform that byte array into an understandable String. The String class has on its ...

36. isset byte

If it's a local variable then the compiler won't let you not initialize it. If it's some kind of field, and you don't specify and initial value, then it will be set to 0. If you want to distinguish the case where no value has been set, then you can use a Byte object reference, initialy null, or pick some byte ...

37. Combine Byte[]

38. IllegalBlockSizeException: Data must not be longer than 64 bytes

/*byte[] decrypted = new byte[bytesIn.length]; System.out.println("Imagebyte length: " + bytesIn.length); byte[] temp = new byte[64]; byte[] temp2 = null; int x, y, z = 0; int repeats = bytesIn.length/64; System.out.println("Iterations: " + repeats); for (z=0; z<64; x++) { temp[x] = (byte) bytesIn[offset+x]; } temp2 = cipher.doFinal(temp); for ...

39. unable to retrieve bytes (correctly)

40. a clarification required on byte length

Hi, Sorry, but you are trying to solve it in the wrong way. An integer in java is 4 bytes, and it's written with the high byte first if you use e.g. DataOutputStream.writeInt(theInt). So the answer is that you should just write the int. An int is binary. The message does not want you to send the text representation of a ...

41. From bytes to String and viceversa

42. problem with byte

43. Writting to Bytes

Hi all Java Minds...... In my project, am in need to write bytes as follows. For eg,. if we take Credit card, the card number should have card id with 16 bytes. The card id was splitted as Card Type - 2 Bytes Version - 2 Bytes Unique ID - 4 Bytes Card Flag - 1 Byte Card Specific Type - ...

44. Creating a Class object from bytes

I do not understand you. You can define a child from URLClassLoader. That exposes protected Class ClassLoader.defineClass(String name, byte[] b, int off, int len) You said you just wanted to call it so you could certainly do that within the code of the child method. And it isn't final so you could override it as well.

45. Turning 4 Bytes into a DWord/Short

A short is 2 bytes, not 4. And there's no dword in Java. One of the things that Java guarantees is the size of all primitives, so you can turn 4 bytes into an int if you want to, with a bit of clever bitshifting, or if you need to do it a lot, using Buffers (ByteBuffer/IntBuffer).

46. Problem when trying to XOR two bytes

47. byte []

I know but I wasn't the one who started the application in the first place, and right now there isn't time to change that... it will be done latter eventually... I saw some method that does it, in the ResultSet interface, but I don't really don't know how to get this done without using prepared stat... thanks sabre150 MeTitus

48. Working with the Bytes

Hi everyone, Having a problem with something I am doing for a cryptography course. It involves cracking triple DES., given a weak key... so here it goes.. I am told that the key is weak of the form: 11:11:11:11:11:11:00:00:XY:XY:XY:XY:XY:XY:00:00:WZ:WZ:WZ:WZ:WZ:WZ:00:00 (and each XY and YZ is a byte of form : 10101011) I have everything going great but one simple java problem. ...

49. Regarding Byte

hi, i have doubt abt the expression that is. byte b = 0; if we write like this i.e b+=1; then there is no erro. if we write like this i.e b = b+1; then there is a compile time error. Why it is giving compile time errro? Thanking u for the answer.

50. Troublesome bytes

I wrote this piece of code to copy a binary file from one drive to another as part of a bigger program. int i=0, ctr=0; //ctr is counter for adding up byte size in the loop byte[] arr = new byte[1024*32]; while ( (i=>0 ) //ism is input stream. { ctr=ctr+i; bout.write(arr); //bout is output stream } System.out.println(inp.length()); //size of ...

52. Aligning byte boundaries

I'm porting some code from C in which the original author has taken a lot of trouble to align data within float[] and int[] arrays to addresses that are multiples of 4. How relevant is this to Java? Eg, if I want to create a 9 element array representing a 3x3 matrix for float values, should I actually allocate a 12 ...

53. Bytes received differs from those send!

have tried to print "len" at both sides and its 5. So the server also uses 5 as the len. when I print the bytes at the client I get: [B@179c285 when I print them at the server I get: [B@7b7072 the wierd thing is that if I convert the bytes at the server to a String I get "sally" eventhough ...

55. error compiling byte

56. Java Class or Object Byte decomposition.

[version 1.6.0_22-b04 of the J2SE SDK] Java.lang.ClassLoader.defineClass(String name, byte[] b, int off, int len); Java.lang.ClassLoader. loadClass(String name) ; allows a Class to be constructed purely from byte data and loaded into memory, as a class or object with the above ClassLoader class and its methods. Implementing the Serializeable interface automatically handles the conversion back to byte data, so an Object can ...

57. How to find the number of bytes received?

One way to find the total would be to create a counter variable that would increment by 1 every time the loop iterates except for the last iteration when read = -1. Declare the variable outside the loop and initialize to 0. Then add 1 to it each time the loop runs. Whether you declare it as an int or long ...

58. byte[] value changes unexpectedly

59. In need of a Code Point sound byte

I am going through volume one of Core Java after studying Java using Absolute Java (Savitch) and I am sorely in need of a sound byte explaining code points. I know they are used to store Unicode values and should be used rather than char when traversing a string. More info would be helpful.