JAVA工具类（5）- MD5加密类

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

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

/**
 * MD5加密类
 * 
 */
public class MD5 {
    private static Logger LOGGER = LoggerFactory.getLogger(MD5.class);

    /**
     * MD5 加密
     * 
     * @param msg
     * @return String
     */
    public static String getMD5(String msg) {
        if (msg == null) {
            return "";
        }
        MessageDigest md = null;
        try {
            md = MessageDigest.getInstance("MD5");
        } catch (NoSuchAlgorithmException e) {
            LOGGER.error("加密失败", e);
            return "encrpt error";
        }
        md.update(msg.getBytes());
        byte[] b = md.digest();

        StringBuilder sb = new StringBuilder(32);
        int i ;
        for (int offset = 0, len = b.length; offset < len; offset++) {
            i = b[offset];
            if (i < 0) {
                i += 256;
            }
            if (i < 16) {
                sb.append("0");
            }
            sb.append(Integer.toHexString(i));
        }

        return sb.toString();
    }

}