MD5加密

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

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class MD5 {
    private static final Logger LOG = LoggerFactory.getLogger(MD5.class);
    /**
     * MD5加密函数
     * @param str 需要加密的字符串
     * @return 返回加密后的信息
     */
    public static String crypt(String str) {
        if (str == null || str.length() == 0) {
         throw new IllegalArgumentException("String to encript cannot be null or zero length");
        }
        StringBuffer hexString = new StringBuffer();
        try {
         MessageDigest md = MessageDigest.getInstance("MD5");
         md.update(str.getBytes());
         byte[] hash = md.digest();
         for (int i = 0; i < hash.length; i++) {
          if ((0xff & hash[i]) < 0x10) {
           hexString.append("0" + Integer.toHexString((0xFF & hash[i])));
          } else {
           hexString.append(Integer.toHexString(0xFF & hash[i]));
          }
         }
        } catch (NoSuchAlgorithmException e) {
            LOG.error("md5加密出现异常", e);
        }
        return hexString.toString();
       }
}