将输入字符串转换为十六进制表示形式

Question

I take a string like "abcd" as a command line argument in my java code. I need to pass this string to my C JNI code which should take this string and use it as a shared memory identity. I am looking to know how and where I can make this string to be representing a hexa value.

Answer 1

Have you tried something like that:

final String myTest = "abcdef";
for (final char c : myTest.toCharArray()) {
    System.out.printf("%h\n", c);
}

If that's what you are looking for, you can have a look at the printf method, it's based on Formatter

Answer 2

所有你需要的是：

Integer.parseInt("abcd", 16);

Answer 3

Java or C? In C, you use strtoul :

#include  <stdlib.h>

int main(int argc, char * argv[])
{
    if (argc > 1)
    {
        unsigned int n = strtoul(argv[1], NULL, 16);
    }
}

Check the manual; when parsing user input it's vital to check for errors, and there are several aspects to this when using strtoul .

Answer 4

public class HexString {
    public static String stringToHex(String base)
    {
     StringBuffer buffer = new StringBuffer();
     int intValue;
     for(int x = 0; x < base.length(); x++)
         {
         int cursor = 0;
         intValue = base.charAt(x);
         String binaryChar = new String(Integer.toBinaryString(base.charAt(x)));
         for(int i = 0; i < binaryChar.length(); i++)
             {
             if(binaryChar.charAt(i) == '1')
                 {
                 cursor += 1;
             }
         }
         if((cursor % 2) > 0)
             {
             intValue += 128;
         }
         buffer.append(Integer.toHexString(intValue) + " ");
     }
     return buffer.toString();
}

public static void main(String[] args)
    {
     String s = "abcd";
     System.out.println(s);
     System.out.println(HexString.stringToHex(s));
}
}