convert hex value to integer

Question

I am working on a method defined in a class that controls the lead object. The desired end result is to produce a unique number for each Lead record. I currently have this working, but the out put is a hex value and I need it to be integer. The field to populate is called "Unique_Reference_number__C". An auto-number field is not sufficient, as there are different formats applied contingent on lead field values. Is there a simple way to convert a hex value to an integer? Here is my method:

private void GenerateRandomNumber(List<Lead> lList){
        System.debug('*lList*********** '+lList.size());
        for(Lead l: lList){
            if(l.Unique_Reference_number__c==null || l.Unique_Reference_number__c==''){
                System.debug('*1*********** ');
                Integer len = 7;
                Blob blobKey = crypto.generateAesKey(128);
                String key = EncodingUtil.(blobKey);
                String pwd = 'ID'+key.substring(0,len);
                l.Unique_Reference_number__c= pwd;
                System.debug('*1*********** '+pwd);
            }

Answer 1

You can convert hex to a value using a few primitive functions:

String hex = '0123456789abcdef';
String[] hexValue = sourceHex.split('');
Decimal result = 0;
for(Integer index = 0; index < hexValue.size(); index++) {
    result = (result * 16) + hex.indexOf(hexValue[index]);
}
return result;

However, you're likely going to lose precision with a 128-bit key, so you might consider using simply a 64-bit key instead (and put it in a Long instead of Decimal).

Answer 2

hex to int conversion:

public static final List<String> hex = '0123456789abcdef'.split('');
public static Integer hexToInt(String str) {
    str = str.toLowerCase();
    String[] hexValue = str.split('');
    Integer retVal = 0;
    for(Integer i = 0; i < hexValue.size(); i++) {
        retVal = (retVal << 4) + hex.indexOf(hexValue[i]);
    }
    return retVal;
}

And for anyone interested the int to hex:

public static final List<String> hex = '0123456789abcdef'.split('');//same as above
public static string intToHex (Integer num){
    integer rem;
    String retVal=''; 
    while(num>0)
    {
        rem = (integer) Math.mod(num, 16);
        retVal = hex[rem] + retVal; 
        num = num / 16;
    }
    return retVal.leftPad(1, '0');//change 1 to 2 if you are converting from hex to strings afterwards
}

Answer 3

Please refer below solution for your problem.

Hex to String Conversion

Answer 4

Here is a function that worked for me:

Decimal hexToDecimal(String hex) {
    String[] hexCharacters = hex.toLowerCase().split('');
    Decimal result = 0;
    for (Integer i = 0; i < hexCharacters.size(); i++) {
        switch on hexCharacters[i] {
            when '0', '1', '2', '3', '4', '5', '6', '7', '8', '9' {
                result = (result * 16) + Integer.valueOf(hexCharacters[i]);
            }   
            when 'a' {
                result = (result * 16) + 10;
            }
            when 'b' {
                result = (result * 16) + 11;
            }
            when 'c' {
                result = (result * 16) + 12;
            }
            when 'd' {
                result = (result * 16) + 13;
            }
            when 'e' {
                result = (result * 16) + 14;
            }
            when 'f' {
                result = (result * 16) + 15;
            }
            when else {
            
            }
        }
    }
    return result;
}

The test code yields the expected results:

System.debug(hexToDecimal('DEAD'));
System.debug(hexToDecimal('BEEF'));
System.debug(hexToDecimal('CAFE'));
System.debug(hexToDecimal('BABE'));

Output:

57005
48879
51966
47806