Unsigned Long in java

Hi all,
I have a code in C which i want to convert into java.. Iam facing problem because java does not support
unsigned long.The code in c look like this:
WCD.cardno = ( SerBuf[3]* 0x00010000UL+
SerBuf[4]* 0x00000100UL+
SerBuf[5]* 0x00000001UL);
I want to convert this code into java. What i have done is something like this
cardno = (tempBuffer[3]*0x01000000 + tempBuffer[4]*0x00010000 + tempBuffer[5]*0x00000100 +tempBuffer[6]*0x00000001);
Can anyone help me out. This program is for serial port implementation.
Thanks
Kiran

kiranJNI wrote:
Basically how can we achieve unsigned long in java???In your case, this isn't going to be a problem for two reasons.
AFAIK, there aren't any numbers where multiplying them as unsigned numbers is going to be different from multiplying them as signed numbers and still give a valid result. To make this easier, let's work with signed vs unsigned bytes. Negative numbers are those in the range 0x80 to 0xFF; these are the only numbers where the "value" of the byte differs between signed and unsigned. Now think of those numbers as unsigned numbers. The only unsigned numbers you could multiply them by and still remain within the range of a byte are 0 and 1. If you multiply by 2, the result is 0x100, which is larger than what a byte can represent. If the result will remain within the range of the data type, it don't think there are any numbers where signed and unsigned multiplication return a different bit pattern.
Furthermore, your example doesn't even need multiplication. You're multiplying by powers of 2, so all you really need is a series of shifts and adds.

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Java newbie help (type casting, 64bit unsigned Long)

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Urgent::Unsigned Long Requirement::Oracle Number(38) to Java conversion

Hi,
I have a Oracle field configured as NUMBER(38). The number in that field gets incremented sequentially and is currently around 5345232341.
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Unsigned Long declaration in JAVA ?????

Hi,
Java doesnt allow unsigned declaration.
I have a 'C' program which does the following:
unsigned long someLongInteger; //in C
someLong>>18;
SomeLong<<14;
SomeLong>>=14;
When I did the same thing in JAVA by declaring someLongInteger as long, it gives me a different result.
Is that because it is considering java Long as signed??
Is there any work around this?
I appreciate your reply
Thank you.

Depending on what you are trying to do, the unsigned right shift operator (>>>) may be of use for this situation.
- K
Hi,
Java doesnt allow unsigned declaration.
I have a 'C' program which does the following:
unsigned long someLongInteger; //in C
someLong>>18;
SomeLong<<14;
SomeLong>>=14;
When I did the same thing in JAVA by declaring
someLongInteger as long, it gives me a different
result.
Is that because it is considering java Long as
signed??
Is there any work around this?
I appreciate your reply
Thank you.

Converting jlong to unsigned long

Hi Everyone,
I am calling a interface from a dll file which need a unsigned long or long as a parameter. In the C program side, how can I convert the jlong to unsigned long or long and then call the interface from the dll file? Also, how can I convert the long back to jlong and return back to Java side? Thank you.
Jacky

Straight cast - BigInteger would be overkill.

Parsing binary file- unsigned longs

Hello everyone.
I'm currently trying to write a quick parser for a binary file format (ASF). However, java's handling of bit shifting and lack of unsigned types is driving me completely mad.
How can I represent an unsigned long?
How can I set the bits for it anyway? It seems that the shift operator can't shift more than an int's worth (it just loops around and starts adding to the other bits- weird).
Thanks in advance.
Simon

ejp wrote:
But why in the world does the following code also do nothing?
long x = 45 << 32;
Try long x = 45L << 32;
The answer appears to be that java uses ints to represent all constants, but this presents some serious problems- namely- how on earth do you get a number bigger than an int into a long?With 'L'. Same as in C or C++. In Visual Basic it's '&'. There's generally something.Where did that come from? Why have I never seen anything like that before?
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As someone pointed out signed/unsigned is actually the same, so long as you interpret it correctly. So to avoid the total stupidity of using twice as much memory for everything I've decided that I am actually going to use the correct types.They're not the correct types. As I pointed out in an earlier post, your 'unsigned longs' must be coming from C or C++ where they are generally 32 bits, so using a 64-bit Java long is incorrect.Where they came from doesn't matter. The spec doesn't say it's a "long"- it says that this particular value is 64bit, and that all values are unsigned. So I do need a Java long.
WHY IN THE WORLD IS JAVA "INTELLIGENT" WHEN DOING THINGS BITWISE? WHICH BRAIN DEAD IDIOT THOUGHT THAT UP? That is broken and is asking for trouble.It is you who is asking for trouble here. The rules of Java are consistent and in conformity with the practice in other programming languages. You've just overlooked several relevant facts.I think I've worked out where I was going wrong here. When doing something like
int i;
long x;
x = x | i;The i is converted to a long before the bitwise operation, so it's not the bitwise operation that's the problem, it's the conversion between int and long?
It's not Java whose stupidity is the issue here ;-)That wouldn't surprise me.
Thanks.

Unsigned types in java

hi there,
i was wondering if there is any way to handle unsigned int in java. im making some byte processing and i have a "switch case" statement like below
so when it comes at 0x80 it does not enter the case because it converts it as -1.
im using java 1.7
ByteBuffer record;
pkgId = record.get();
switch ((int) pkgId) {
case 0x75:
break; /* 117 */
case 0x7D:
break; /* 125 */
case 0x80:
break; /* 128 */
case 0x82:
break; /* 130 */
case 0x86:
break; /* 134 */
case 0x87:
break; /* 135 */
}

user8999602 wrote:
hi there,
i was wondering if there is any way to handle unsigned int in java.Use a long.
im making some byte processing and i have a "switch case" statement like below
so when it comes at 0x80 it does not enter the case because it converts it as -1.
im using java 1.7
ByteBuffer record;
pkgId = record.get();
switch ((int) pkgId) {
case 0x75:
break; /* 117 */
case 0x7D:
break; /* 125 */
case 0x80:
break; /* 128 */
case 0x82:
break; /* 130 */
case 0x86:
break; /* 134 */
case 0x87:
break; /* 135 */
}Looks more like you want an unsigned byte. The usual approach to that is to use an int, but you need to mask it. The byte 0x80 has the value -128, so when you simply cast to an int, it sign extends it, and you get 0xFFFFFF80, which is an int value of -128.
int pkgIdInt = pkgId & 0xFF;
switch (pkgIdInt);Alternatively, you could just cast each case value to byte, but that's too cluttered for my taste.

Why is there no unsigned type is java?

Just wondering? Why no unsigned int or unsigned long? I have often used these in the past but java requires me to do some clever stuff to get over the limitation.

i found this on the net somewhere. it doesn't mention anything about java but it does seem to fit the typical "don't include anything that can be confusing or misunderstood" mold that java utilizes:
"One problem is that unsigned types tend to decrease your
ability to detect common programming errors. Another is that
they often increase the likelihood that clients of your classes
will use the classes incorrectly.
Consider first error detection. Suppose a programmer defines
an Array object as follows:
int f(); // f and g are functions that return
int g(); // ints; what they do is unimportant
Array<double> a(f()-g()); // array size is f()-g()
There�s nothing wrong with this definition for a, except for the
possibility that the programmer writing it made an error. Instead
of the size of the array being f()-g(), perhaps it
should have been g()-f(). Or maybe it should have been
f()+g(). Or possibly it should have been f()-g()+1; off-byone
errors are certainly common enough. Heck, it�s even possible
that f()-g() is correct, but f() or g() is returning a
bad value. Any of these scenarios could lead to the Array
constructor being passed a size that was less than zero. As
the author of the Array class, there�s no way you can keep
clients from making mistakes such as these, but you can do
the next best thing: you can detect such errors and act on
them.
Well, actually, maybe you can�t. You can�t if you declared Array�s
constructor to take an unsigned value, because if a
negative number is passed to a function as an unsigned, the
number seen by the function isn�t negative at all. Instead, it�s
a very large positive number. As a result, you�d have no way
within the Array constructor of distinguishing between a
large, but valid, positive size value and a large, but invalid,
positive size value arising from passing in a negative number.
Hence, you�d be unable to detect programming errors that result
in negative array sizes being requested. Because such errors
are not uncommon, this makes your class easy to use
incorrectly."

Signature: FSUpdateOperationStatus(void const*, TCountedPtr TCFURLInfo const&, long long, long long, long long, long long, unsigned long). No support Docs on file for this problem. Multiple crashes on opening Firefax. Running OSX 10.6.4.

Signature:
FSUpdateOperationStatus(void const*, TCountedPtr<TCFURLInfo> const&, long long, long long, long long, long long, unsigned long)
No Support Docs on File.
Firefox crashes every time it is opened.
UUID 38fc1438-492f-4ce3-91d4-5ef922101027
Time 2010-10-27 11:19:32.620395
Uptime 11
Last Crash 110 seconds before submission
Install Age 610295 seconds (1.0 weeks) since version was first installed.
Product Firefox
Version 3.6.11
Build ID 20101012104758
Branch 1.9.2
OS Mac OS X
OS Version 10.6.4 10F569
CPU x86
CPU Info GenuineIntel family 6 model 15 stepping 11
Crash Reason EXC_BAD_ACCESS / KERN_PROTECTION_FAILURE
Crash Address 0x8
User Comments
Processor Notes
EMCheckCompatibility Fal

Looking at the crash log it looks like AE might be crashing in:
net.telestream.wmv.export
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--c

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Hi there,
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% man -s 3C strtoull

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Hi,
I'm lusing a c/c++ step type from TestStand.
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unsigned long
unsigned short
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integer
unsigned integer
etc...
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Hi Doug,
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typedef struct tagFCPortConfig
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Rafi

How to express the unsigned byte in Java?

we know that data are normally in unsigned byte format when communicating with COMM. How to express the unsigned byte in Java? java only supports 127 ~ -127 as byte, but I need 255~0.
Anyone know how?
Thanks!

You mean when a byte ( -127) converts to a int, it
will become 255?In your example -1 will be printed in both cases because of the implicit conversion Java makes. The 0xff in the byte will become 0xffffffff in the int. Both are interpreted as -1.
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How to map C/C++ unsigned char[] to Java

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why did you classify this as byte? how do you did
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Hi Amy;
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www.vartortech.com

Should using unsigned long long be this difficult?

So I have a number. Possibly a big number that I would like to use. When I do the following, valueToGet is fine (1252904880010) when it returns but when I step to currentTimeStamp the value is something like 18446744072483981194.
I can only assume that maybe I am missing some basic understanding of how methods return this value.
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unsigned long long currentTimestamp = [self getUnsignedLongLong: timeString];
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-(unsigned long long)getUnsignedLongLong:(NSString*)longString
NSScanner* scanner = [NSScanner scannerWithString:longString];
unsigned long long valueToGet;
if([scanner scanLongLong:&valueToGet] == YES) {
return valueToGet;
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That is so discouraging that code that SHOULD work actually does work for everyone but me. Here is the data after I changed the following code. I had to use scanHexLongLong to actually return an unsigned long long instead of just long long. Is it possible that maybe something is just stomping on that memory location somehow and giving me bad data? But consistently the same way? Seems odd.
2009-09-14 02:36:37.325 TestApp[46744:20b] lVal=322333076619280
2009-09-14 02:36:37.530 TestApp[46744:20b] currentTimeStamp (converted from timeString): 322333076619280
Run using:
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unsigned long long lVal = [self getUnsignedLongLong:@"1252904880010"];
NSLog(@"lVal=%qu", lVal);
-(void)processTimestampReceived
NSString* timeString = @"1252904880010";
unsigned long long currentTimestamp = [self getUnsignedLongLong: timeString];
NSLog(@"currentTimeStamp (converted from timeString): %qu", currentTimestamp);
-(unsigned long long)getUnsignedLongLong:(NSString*)longString
NSScanner* scanner = [NSScanner scannerWithString:longString];
unsigned long long valueToGet;
if([scanner scanHexLongLong:&valueToGet] == YES) {
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Unsigned Long in java

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