StringUtil.java

package com.lzx.lock.utils;

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

/**
 * Created by xian on 2017/2/17.
 */

public class StringUtil {

    public static String toMD5(String source) {
        if (null == source || "".equals(source))
            return null;
        try {
            MessageDigest digest = MessageDigest.getInstance("MD5");
            digest.update(source.getBytes());
            return toHex(digest.digest());
        } catch (NoSuchAlgorithmException e) {
        }
        return null;
    }

    public static String toHex(byte[] buf) {
        if (buf == null)
            return "";
        StringBuffer result = new StringBuffer(2 * buf.length);
        for (int i = 0; i < buf.length; i++) {
            appendHex(result, buf[i]);
        }
        return result.toString();
    }

    private final static String HEX = "0123456789ABCDEF";

    private static void appendHex(StringBuffer sb, byte b) {
        sb.append(HEX.charAt((b >> 4) & 0x0f)).append(HEX.charAt(b & 0x0f));
    }

}