package com.uas.eis.utils;

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

public class MD5Util {

	/**
	 * MD5加密
	 * @param message
	 * @return
	 */
	public static String getEncryption(String message){
		String result = "";
		if(message != null){
			try {
				MessageDigest md = MessageDigest.getInstance("MD5");		//指定加密方式
				//加密
				byte[] bytes = md.digest(message.getBytes());
				for(int i = 0; i < bytes.length; i++){
					// 将整数转换成十六进制形式的字符串 这里与0xff进行与运算的原因是保证转换结果为32位
					String str = Integer.toHexString(bytes[i] & 0xFF);
					if(str.length() == 1){
						str += "F";
					}
					result += str;
				}
			} catch (NoSuchAlgorithmException e) {
				e.printStackTrace();
			}	
		}
		return result;
		
	}

	public static String encodeByMD5(String originString) {
		if (originString != null) {
			try {
				MessageDigest md = MessageDigest.getInstance("MD5");
				byte[] results = md.digest(originString.getBytes());
				String resultString = byteArrayToHexString(results);
				return resultString.toUpperCase();
			} catch (Exception ex) {
				ex.printStackTrace();
			}
		}
		return null;
	}

	public static String byteArrayToHexString(byte[] bArr) {
		StringBuffer sb = new StringBuffer(bArr.length);
		String sTmp;

		for (int i = 0; i < bArr.length; i++) {
			sTmp = Integer.toHexString(0xFF & bArr[i]);
			if (sTmp.length() < 2){
				sb.append(0);
			}
			sb.append(sTmp.toUpperCase());
		}
		return sb.toString();
	}
	/**
	 * hex字符串转byte数组
	 * @param inHex 待转换的Hex字符串
	 * @return  转换后的byte数组结果
	 */
	public static byte[] hexToByteArray(String inHex){
		int hexlen = inHex.length();
		byte[] result;
		if (hexlen % 2 == 1){
			//奇数
			hexlen++;
			result = new byte[(hexlen/2)];
			inHex="0"+inHex;
		}else {
			//偶数
			result = new byte[(hexlen/2)];
		}
		int j=0;
		for (int i = 0; i < hexlen; i+=2){
			result[j]=(byte)Integer.parseInt(inHex.substring(i,i+2),16);
			j++;
		}
		return result;
	}
}