Java十进制/ ASCII和基数转换

Question

I'm converting code from perl to java. I'm sort of stuck on finding the equivalents in java.

Here's my Perl code:

    for($i = 0; $i < strlen($hex_); $i = $i + 2)
    {
      $ascii = $ascii.chr(hexdec(substr($hex_, $i, 2))); 
    }

so in java i can do hex.substring(i,2). I got that part.

How would I do the chr and hexdec part in Java?

Here's what I have so far

Answer 1

There is no need for you to go about parsing hexadecimal numbers manually, you can just use Integer.parseInt(String s, int radix) . Similarily, there is an Integer.toString(int i, int radix) which will convert your integer to a String with the desired base.

Answer 2

I'm actually extremely surprised you didn't use pack for your Perl version!

$ascii = pack 'H*', $hex_;

Anyway, the Java port of your Perl code, if you want to code it manually (as opposed to using something like Apache Commons Codec ) is:

StringBuilder sb = new StringBuilder();
for (int i = 0; i + 1 < hex.length(); i += 2)
    sb.append((char) Integer.parseInt(hex.substring(i, i + 2)));
String ascii = sb.toString();