md5加密

 

import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

public class MySecurity {

    public static String MD5(byte[] b) {
        byte[] md5b = null;
        char[] digest = "0123456789abcdef".toCharArray();
        MessageDigest md;
        try {
            md = MessageDigest.getInstance("MD5");
        } catch (NoSuchAlgorithmException e) {
            e.printStackTrace();
            return null;
        }
        md5b = md.digest(b);
        char[] c = new char[32];
        int k = 0;
        for (int i = 0; i < 16; i++) {
            byte b1 = md5b[i];
            c[k++] = digest[(b1 & 0xf0) >> 4];
            c[k++] = digest[b1 & 0xf];
        }
        return new String(c);
    }

    public static void main(String[] args) {
        String s = "a";
        System.out.println(s);
        System.out.print(MD5(s.getBytes()));

    }

}