Hex to Int

Hey guys, can someone help me out here ..... i need to convert hex to int. I'm relatively new to java. Kindly bail me out here

Check out the Integer static method with the signature:
public static int parseInt(String s, int radix) throws NumberFormatException
You should note that "int" is a primitive java type for (nonfactional)
numbers, and "hex" is (presumably) a String. That is they are very
different sorts of thing. The "radix" in the method referred to above
is 16 in the case of hex strings.
There is also a static decode(String) method.
You can read about both here: http://java.sun.com/j2se/1.5.0/docs/api/java/lang/Integer.html

Similar Messages

NSMutableString getCString misbehaves, does not show some characters

Hi everyone,
This is my first time here.
I have written a small tool for Cocoa / MacOSX 10.5 and I am trying to save a text to a file, but some characters such as # appear as hex 0x0.
Source: -----
int len = [results length] * sizeof(char);
char *buffer = malloc(len);
[results getCString: buffer maxLength: len-1 encoding: NSWindowsCP1250StringEncoding];
NSData *dt = [NSData dataWithBytes: buffer length: len];
[fileManager createFileAtPath: @"/Volumes/MacBackup/results.sh" contents: dt attributes:nil];
The # and the final 2-3 characters appear as 0x0 in a hex viewer. I have tried almost all encodings, but to no avail. Can anyone tell me how to make it work? Do I have to enter the # directly in the char buffer as ASCII char or am I missing something about the encoder?
Btw, I am a newb at Mac programming, but I come from a solid Windows programming background, but please don't hold that against me :P.
Message was edited by: TTDeath
Message was edited by: TTDeath

Hi TT, and welcome to the Dev Forum!
TTDeath wrote:
I have written a small tool for Cocoa / MacOSX 10.5 and I am trying to save a text to a file, but some characters such as # appear as hex 0x0.
int len = [results length] * sizeof(char); // <-- need to add one here
char *buffer = malloc(len);
The NSString length method doesn't count a terminator; i.e. it's analogous to strlen(), so if you convert an ASCII C string to a NSString object, the return from [results length] will be the same as strlen(source). I'm not sure there wasn't something else going on at your end, since this length error only strips the trailing char from the source string. In any case, the following code should work for you:
// made from MAC OS X->Command Line Utility->Foundation Tool template
#import <Foundation/Foundation.h>
int main (int argc, const char * argv[]) {
NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];
// insert code here...
NSLog(@"Hello, World!");
NSString *results = @"A string with # embedded
int len = [results length] * sizeof(char) + 1; // <--
char *buffer = malloc(len);
BOOL bError = [results getCString: buffer
maxLength: len encoding: NSWindowsCP1250StringEncoding];
NSLog(@"getCString returns %d", bError);
NSData *dt = [NSData dataWithBytes: buffer length: len];
NSLog(@"dt=%@", dt);
NSFileManager *fileManager = [NSFileManager defaultManager];
// I don't recommend testing in a system directory -
// remember to substitute your home dir name here:
bError = [fileManager createFileAtPath: @"/Users/Ray/results.sh"
contents: dt attributes:nil];
NSLog(@"createFileAtPath returns %d", bError);
[pool drain];
return 0;
// [Session started at 2009-12-05 16:47:41 -0800.]
// 2009-12-05 16:47:41.045 TT[463:10b] Hello, World!
// 2009-12-05 16:47:41.048 TT[463:10b] getCString returns 1
// 2009-12-05 16:47:41.049 TT[463:10b] dt=<41207374 72696e67
// 20776974 68202320 656d6265 64646564 0a00>
// 2009-12-05 16:47:41.054 TT[463:10b] createFileAtPath returns 1
// rays-imac:~ Ray$ cat results.sh
// A string with # embedded
- Ray

Please help understand this error...

I am developing a small Hash Calculator that calculates MD5/ SHA Hash.
It has 2 modes,
1. Text mode in which i have a JTextField - userText where i can enter the text and then when i click on calculate the corresponding hash of the text is evaluated.
2. File mode in which then the JTextField gets disabled (locked or non editable) and i have button that gets visible through which i can then select a file (through JFileChooser) and when i select a file, i put it's absolute path in the JTextField - userText. and then when i click on calculate this code is run...
FileInputStream in=new FileInputStream(userText.getText());
                         int length=0;
                         while((length=in.read(buffer))!=-1)
                              md5.update(buffer,0,length);
                         digest=md5.digest();
                         hex="";
                         for (int i = 0; i < digest.length; i++)
                              int b = digest[i] & 0xff;
                              if (Integer.toHexString(b).length() == 1) hex = hex + "0";
                              hex = hex + Integer.toHexString(b);
                         hash.setText(algorithm.getSelectedItem().toString()+" Hash: "+hex);
                         copyString(hex);
                         status.setText(algorithm.getSelectedItem().toString()+" Hash copied to ClipBoard",Color.RED);
                         in.close();Now what i am getting is that in case i calculate a hash of a text (default starting mode is text mode) and then change the mode to File then it is working absolutely fine, but if right in the beginning, at the starting i go and select the File Mode, then when i click on calculate i get a strange error.
I have the stack trace of it :
Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
     at java.io.FileInputStream.read(Unknown Source)
     at MD5HashCalculator.calculate(MD5HashCalculator.java:371)
     at MD5HashCalculator.access$3(MD5HashCalculator.java:338)
     at MD5HashCalculator$12.actionPerformed(MD5HashCalculator.java:280)
     at javax.swing.AbstractButton.fireActionPerformed(Unknown Source)
     at javax.swing.AbstractButton$Handler.actionPerformed(Unknown Source)
     at javax.swing.DefaultButtonModel.fireActionPerformed(Unknown Source)
     at javax.swing.DefaultButtonModel.setPressed(Unknown Source)This weird thing is happening only the first time and it is happening in the line of the while loop basically
while((length=in.read(buffer))!=-1)I am unable to understand the error, please help.
What exactly is happening , and more specifically , why is it happening only if i did the mode change right in the beginning for the first time...??

this buffer since it had a null value was giving the
error. I replaced the thing by
byte buffer[]="".getBytes();
I'm not sure that's the best thing to do.
I was reluctant at first to initialise the buffer
with some bytes as i thought it might effect the md5
value if it had some value in the beginning, You're supposed to create an empty byte array, e.g. like so:
byte[] buffer = new byte[1024];In this case, the read method will read at most 1024 bytes into the buffer. The number of bytes it actually reads is returned to you. If it returns 12, say, you should only use the 12 first bytes in the array since those are the bytes that were actually read in. Whatever was in those 12 slots in the array before you called read is overwritten. Then you call read again to see if there are more bytes available, until it returns -1 to signal that there is nothing more to read.
but i
have re-checked it accurately, the code is now
working fine and the MD5 has is coming perfectly.
This seems strange, as
"".getBytes();returns a byte array of zero length, which to me suggests you would end up in an infinite loop. But if you say so...

Different values for encryption and Decryption ...

The following program takes a string as input ...
it uses tripel DES algorithm for encryption/decryption...
The ciphertext is converted into hexachar string by the following process..
1.first the cipher text is converted into byte format ..
2.Then each byte is converted into two hexa-characters ..
3.a string is formed by appending all the hexa-characters.
when deconverting this hexa-character string into original cipher text
Iam not getting the same byte string ...pls check and do let me know if you find out any mistake..
BUT THE FINAL DECRYPTION IS WORKING GOOD (I.E I GOT THE ORIGINAL INPUT STRING AFTER DECRIPTION ...BUT THE CIPHER TEXT IS NOT SAME ..)
import java.security.*;
import javax.crypto.*;
import java.io.*;
public class endecryptor
     public static void main( String [] args ) throws Exception
          if ( args.length != 1 )
                    System.err.println("Usage: java SimpleExample text" );
                    System.exit(1);
          endecryptor d = new endecryptor();
          String text = args[0].trim();
          System.out.println("Generating a DESede (TripleDES) key ... " );
          //add the provider
          Provider sunJce = new com.sun.crypto.provider.SunJCE();
          Security.addProvider(sunJce);
          //create a triple DES key
          KeyGenerator keyGenerator = KeyGenerator.getInstance("DESede");
          keyGenerator.init(168); //initialize with the keysize
          Key key = keyGenerator.generateKey();
          System.out.println("Key Algorithm :"+key.getAlgorithm());
          System.out.println("Key Algorithm :"+key);
          System.out.println( "Done generating the key." );
          //create a cipher using a key to initialize it
          Cipher cipher = Cipher.getInstance( "DESede/ECB/PKCS5Padding" );
          cipher.init( Cipher.ENCRYPT_MODE, key );;
          byte[] plaintext = text.getBytes( "UTF8" );
          //print out the bytes of the plaintext
          System.out.println( "\nPlaintext: "+plaintext);
          //perform the actual encryption
          byte[] ciphertext = cipher.doFinal( plaintext);
          //print out the ciphertext
          System.out.println( "\n\nCiphertext: "+ciphertext );
          System.out.println("Converting the cyphertext into hexachar ...");
          String hexcharString = d.bytes2Hex(ciphertext);
          System.out.println("hexcharString::"+hexcharString);
          //re initialize the cipher to decrypt mode
          byte[] tempCipherText = d.decryptorOfHexcharString(hexcharString);
          System.out.println( "after decryptor (for decrypting the hexchar) function ....");
          System.out.println("Temp Ciphertext ::"+ tempCipherText);
          System.out.println( "\n\nCiphertext: "+ciphertext );
          System.out.println("Decrypting the string ...");
          cipher.init( Cipher.DECRYPT_MODE, key );
          //perform the decryption
          //byte[] decryptedText = cipher.doFinal( ciphertext );
          byte[] decryptedText = cipher.doFinal( tempCipherText );
          String output = new String( decryptedText, "UTF8" );
          System.out.println( "\n\nDecrypted Text:" + output );
     public String bytes2Hex(byte[] raw) {
     // here is the code to convert a byte array to hex rep
     int higherbyte; // higher bits in the byte
     int lowerbyte; // the lower bits in the byte
     StringBuffer sb = new StringBuffer();
     int i;
     for (i = 0; i < raw.length; i++) {
     lowerbyte = (raw[i] & 0xf);
     higherbyte = (raw[i] >>> 4) & 0xf;
     sb.append(oneByte2HexChar(higherbyte));
     sb.append(oneByte2HexChar(lowerbyte));
     return sb.toString();
     } // end method bytes2Hex
     public char oneByte2HexChar (int fourbits) {
     // converts byte lower bits to hex char
     if (fourbits < 10) { return (char)('0' + fourbits); }
     return (char) ('a' + (fourbits - 10)) ;
     } // end method oneByte2HexChar
     public byte[] decryptorOfHexcharString(String hexcharStr)
               int checker=0;
               char ch1,ch2;
               byte tempbyte1,tempbyte2,resultbyte;
               int k=0,stringlength;
               boolean lengthChecker;
               int len = hexcharStr.length();
               byte[] tempCipher = new byte[len/2];
               System.out.println("length of the hex string:"+len);
               stringlength = hexcharStr.length();
               if(stringlength%2 == 0)
                    lengthChecker = true;
               else
                    lengthChecker = false;
               for(int i=0;i<stringlength;)
                    ch1 = hexcharStr.charAt(i);
                    tempbyte1 = (byte) getIntValue(ch1);
                    tempbyte1 = (byte) (tempbyte1 << 4);
                    if(i == stringlength-1)
                    if(lengthChecker)
                         ch2 = hexcharStr.charAt(i+1);
                         tempbyte2 = (byte) getIntValue(ch2);
                    else
                         tempbyte2 = 0;
                    else
                         ch2 = hexcharStr.charAt(i+1);
                         tempbyte2 = (byte) getIntValue(ch2);
                    resultbyte = (byte) (tempbyte1 | tempbyte2);
                    tempCipher[k++] = resultbyte;
                    i += 2;
               return tempCipher;
          public int getIntValue(char character)
               int val;
               if(Character.isDigit(character))
                         val = ((int) character ) - '0';
               else
                         val = ((int) character) + 10 - 'a';
               return val;

Dude - the only problem I can see is when you do stuff like this:        System.out.println("\nPlaintext: " + plaintext); That does NOT "print the bytes of" plaintext[]; it just spits out the array's hashcode. Two arrays where that value is different are just two different array variables - says nothing about the content of those arrays.
Do your byte2hex trick on each ciphertext, and they'll be the same.
One final thing - please learn to use the [ code ] tags when you post code; it helps us read your code and respond to it.
Grant

Converting cstring to xstring

What is cstring & Xstring ?
how to do the conversion ?

data: w_char type string,               " Character String .Dynamic Length
         w_hex type Xstring ,              " Hexadecimal String.DYnamic Length
      w_int type i.
    w_hex = 'ABC021343'.
w_char = w_hex.                " Conversion From Hex to Char
w_int = w_hex.                    " Conversion From Hex to INT
write :/ w_int.
write : w_char.
[Check Conversion Rules|http://help.sap.com/saphelp_webas620/helpdata/en/fc/eb3434358411d1829f0000e829fbfe/content.htm]
Regards,
Gurpreet

Int to Hex Progam

Could someone help resolve this problem : I have created a program to change int to hex but it does not seem to woek ? What could be wrong ?
import java.lang.String;
import javax.swing.JOptionPane; // import class JOptionPane
public class KcHexConverter {
public static void main( String args[] )
     String value, s;// first string entered by user
     int ni=0;
          // read in first number from user as a string
          value = JOptionPane.showInputDialog( "Enter integer" );
// convert numbers from type String to type Hex
          ni = Integer.parseInt(value, 16);
          s = Integer.toHexString(ni);
// display the results
JOptionPane.showMessageDialog(null, "The equvalent in Hexadecimal is: " +s, "Results", JOptionPane.PLAIN_MESSAGE );
System.exit( 0 ); // terminate the program
}

Hi
you need to change:
ni = Integer.parseInt(value);//no need for a radix it is base 10
and you should catch a possible NumberFormatException (sb enters a letter).

Converting a Hex String to an Int

I have a quick question. I am attempting to encode an Integer as a Hex String using Integer.toHexString(), which produces a max of eight hex characters.
I then need to convert this string back to an integer. I tried using Integer.parseInt(string, 16), but this only works for positive integers, because it expects a negative number to be designated with a "-" sign, which is the behavior of Integer.toString(int, 16).
I do not wish to represent the "-" sign in that manner, because I want to minimize the length of the hex string.
This method is time-critical, and I would like it to be as simple as possible, so I am looking for a solution in the standard libraries. Does anybody know of a method to convert the eight character hex representation which includes the sign bit as part of the eighth character back to an int using a method provided by the libraries?

int intVal = (int)Long.parseLong(str, 16);

Int to hex?

Is there a predefined way to change an integer to hexidecimal?
For Instance:
int ip1 = 166;
ip1 to hex = 0xA6
I had thought I read about this in the docs, but can't find it.
Thanks

I appreciate the response. To explain my reasoning: I am building a byte array and I need to put each of the four number segments of an ip address into the array.
Would this work? Forgive the fast-coding.
String SrvrIP = srvrIpAddr.getHostAddress(); // i.e 166.10.10.0
StringTokenizer ip = new StringTokenizer( SrvrIP, "." );
int ip1 = Integer.parseInt(ip.nextToken());
int ip2 = Integer.parseInt(ip.nextToken());
int ip3 = Integer.parseInt(ip.nextToken());
int ip4 = Integer.parseInt(ip.nextToken());
byte[] buf = new byte[512];                // Does it give me this??
buf[0] = Integer.toHexString(ip1);              // buf[0] = 0xA6
buf[1] = Integer.toHexString(ip1);              // buf[1] = 0x0A
buf[2] = Integer.toHexString(ip1);              // buf[2] = 0x0A
buf[3] = Integer.toHexString(ip1);              // buf[3] = 0x00Thanks

USB Output Buffers - int to Hexed Chars

Hi all
With regards sending data to a USB device I set up a char like so:
size_t bufferSize = 8;
char *buffer = malloc(bufferSize);
I can then populate my bytes in hex (which seems to be the normal way of doing it).
    buffer[0] = 0xFF;
    buffer[1] = 0xEA;
The two fold question is will I have any issues if i populate the char buffers with integers?
    int value = 256;
    buffer[0] = value;
or does it have to be in hex?
If it requires hex (or even if not cos it would be good to know). What the best way to convert and integer to a hexed char?
Cheers
Steve

It doesn't matter if you specify the value in hexadecimal, decimal, octal or binary (or any other numbering system for that matter).
A number has the same value no matter what base you use.

String to Int and Int to String

How can I convert a string to Int & and an Int to String ?
Say I've
String abc="234"
and I want the "int" value of "abc", how do I do it ?
Pl. help.

String.valueOf(int) takes an int and returns a string.
Integer.parseInt(str) takes a string, returns an int.
For all the others long, double, hex etc. RTFM :)

How to convert hex into a string value

hei evryone!
can anyone please help me on how to convert a hex value into a string suppose.. Example i want to convert 4275646479 which is a hex value, into a string "BUDDY"? how will i do that???
Any suggestion, tutorial site would be appreciated?
Thx!

something like this will convert string to byte[]
e.g.
you want to convert following.
656667 => ABC
String toConvert = "656667";
byte[] returnVal = String2byteArr (toConvert );
String FinalStr = new String(returnVal);
public static byte[] String2byteArr(String Result)
byte[] byteRet = new byte[Result.length()/2];
int k=0;
for (int j=0; j<(Result.length()); j+=2)
try
Integer I = new Integer (0);
I = I.decode ("0x"+Result.substring(j, j+2));
int i = I.intValue ();
if (i > 127)
i = i - 256;
byteRet[k++] = new Integer(i).byteValue();
catch(Exception e)
System.err.println(e);
return byteRet;
}// String2byteArr
Hope this will help you, So that i can get 3$ (:-)
Avi

Help needed in understanding conversion alghorithm from byte to hex

Hi, I'm studying the following code:
public static char[] byteToHex(byte[] data) {
char[] retValue = new char[data.length * 2];
int value = 0;
int highIndex = 0;
int lowIndex = 0;
for (int i = 0; i < retValue.length; i++) {
    value = (data[i] + 256) % 256;
    highIndex = value >> 4;
    lowIndex = value & 0x0f;
    retValue[i * 2 + 0] = hexTable[highIndex];
    retValue[i * 2 + 1] = hexTable[lowIndex];
return retValue;
}There are few things (the most important) which I don't understand about the above code.
I understood that what's returned has got double size related to what's passed in because a char takes 16 bits while a byte takes 8.
1) I don't understand why each byte must be first added 256 and then % with 256 (returning the same value - Is this to eliminate negative values?)
2) I do understand that each byte is transformed in two hexadecimal values: one is the highIndex (first 8 bits) and the second is the lowerIndex (last 8 bits) and that each value is tranformed in its hexadecimal value from the array of hex values.
3) What I don't really understand is why the highIndex is calculated as: value >> 4
and the lowest index is calculated as value 0x0f (is this last also to eliminate negative values?)
If someone could clarify this for me, I'd be very grateful.
Thanks.
Marco

So, does this mean that we add 256 to eliminate the sign?No. You need the whole line to convert a signed byte into an int between 0 and 255.
A simpler way to do this would be
value = data[i] & 0xFF;
This moves down the higher bits so that it turnsinto lower bits. i.e. we need it to >be between 0 and
15.
Is this shifted of 4 because Math.pow(2, 4) = 16.0?Doing in this case, x >>4 is the same as x / 16
This leaves only the lowest 4 bits.Is the following what happens?There are no char values produced. Using 0000 as an example is not a good idea as you can change it in many ways and it is still 0000
>
Received as initial value:
byte: 0000 0000
What we need to obtain:
char: 0000 0000 0000 0000
The first 4 bits of the above byte are shifted of 4
positions to find the hexadecimal equivalent (if from
2 I want to get to 16 I have to do the opposite of
powering a number by 4); The last four bits of the
byte are extracted because of the '&' operator with
0x0f (which in binary is 1111 - Therefore all the '1'
are kept)?Yes.

Incompatible types - found java.lang.String but expected int

This is an extremely small simple program but i keep getting an "incompatible types - found java.lang.String but expected int" error and dont understand why. Im still pretty new to Java so it might just be something stupid im over looking...
import java.io.*;
import javax.swing.*;
import java.awt.event.*;
import java.awt.*;
public class Lab
public static void main(String []args)
int input = JOptionPane.showInputDialog("Input Decimal ");
String bin = Integer.toBinaryString(input);
String hex = Integer.toHexString(input);
System.out.println("Decimal= " + input + '\n' + "Binary= " + bin + '\n' + "Hexadecimal " + hex);
}

You should always post the full, exact error message.
Your error message probably says that the error occurred on something like line #10, the JOptionPane line. The error is telling you that the compiler found a String value, but an int value was expected.
If you go to the API docs for JOptionPane, it will tell you what value type is returned for showInputDialog(). The value type is String. But you are trying to assign that value to an int. You can't do that.
You will need to assign the showInputDialog() value to a String variable. Then use Integer.parseInt(the_string) to convert to an int value.

Converting a hex String to its corresponding hex value...?

Yeah, I'm having quite a bit of fun guessing this one... :p
I have a string of n characters and have used Integer.toHexString( ( int )str.charAt( i ) ) to convert each character to a string representing its hex value. Now I need to USE that value for bit-wise operations, like, say, applying the AND, OR, etc. operators...
Example:
hexvalue &= 0xC000FFFF; //the second value is the one extracted from the string;
How can achieve this...? Any help is greatly appreciated... :}

Since a Java char is numerically a Java short, you can apply bitwise operators to chars directly - the conversion to hex simply changes the way that the char is viewed; the result can also be viewed as a number in other bases.
For instance, the char 'A' can be also be represented as any of the following values:
binary - 1000001
octal - 101
decimal - 65
hex - 41
Likewise, 'Z' can also be viewed as
binary - 1011010
octal - 132
decimal - 90
hex - 5A
"Anding" the letter 'A' with 'Z' ('A' & 'Z') or doing the same using any of the other representations will result in (binary 1000000, octal 100, decimal 64, or hex 40) - the bit pattern is the same, only the representation of the result varies.

Convert UTF-8 (Unicode) Hex to Hex Byte Sequence while reading file

Hi all,
When java reads a utf-8 character, it does so in hex e.g \x12AB format. How can we read the utf-8 chaacter as a corresponding byte stream (e.g \x0905 is hex for some hindi character (an Indic language) and it's corresponding byte sequence is \xE0\x45\x96).
can the method to read UTF-8 character byte sequence be used to read any other (other than Utf 8, say some proprietary font) character set's byte sequence?

First, there's no such thing as a "UTF-8 character". UTF-8 is a character encoding that can be used to encode any character in the Unicode database.
If you want to read the raw bytes, use an InputStream. If you want to read text that's encoded as UTF-8, wrap the InputStream in an InputStreamReader and specify UTF-8 as the encoding. If the text is in some other encoding, specify that instead of UTF-8 when you construct the InputStreamReader. import java.io.*;
public class Test
// DEVANAGARI LETTER A (अ) in UTF-8 encoding (U+0905)
static final byte[] source = { (byte)0xE0, (byte)0xA4, (byte)0x85 };
public static void main(String[] args) throws Exception
    // print raw bytes
    InputStream is = new ByteArrayInputStream(source);
    int read = -1;
    while ((read = is.read()) != -1)
      System.out.printf("0x%02X ", read);
    System.out.println();
    is.reset();
    // print character as Unicode escape
    Reader r = new InputStreamReader(is, "UTF-8");
    while ((read = r.read()) != -1)
      System.out.printf("\\u%04X ", read);
    System.out.println();
    r.close();
} Does that answer your question?

Hex to Int

Similar Messages

Maybe you are looking for