根据字符串生成MD5

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

public class MD5 {
    // MD5変換
    public static String Md5(String str) {
        if (str != null && !str.equals("")) {
            try {
                MessageDigest md5 = MessageDigest.getInstance("MD5");
                char[] HEX = { ‘0‘, ‘1‘, ‘2‘, ‘3‘, ‘4‘, ‘5‘, ‘6‘, ‘7‘, ‘8‘, ‘9‘, ‘a‘, ‘b‘, ‘c‘, ‘d‘, ‘e‘, ‘f‘ };
                byte[] md5Byte = md5.digest(str.getBytes("UTF8"));
                StringBuffer sb = new StringBuffer();
                for (int i = 0; i < md5Byte.length; i++) {
                    sb.append(HEX[(int) (md5Byte[i] & 0xff) / 16]);
                    sb.append(HEX[(int) (md5Byte[i] & 0xff) % 16]);
                }
                str = sb.toString();
            } catch (NoSuchAlgorithmException e) {
            } catch (Exception e) {
            }
        }
        return str;
    }
    
}