md5加密（1）

package com.js.ai.modules.pointwall.util;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
/**
 * 
 * @ClassName: MD5Utils
 * @Description: 邀请码生成
 * @author: xfzhong
 * @date: 2017年4月10日 
 */
public class MD5Utils {
	public static String generate(String user ){
		String cacheKey;
		try {
			final MessageDigest mDigest = MessageDigest.getInstance("MD5");
			mDigest.update(user.getBytes());
			cacheKey = bytesToHexString(mDigest.digest());
		} catch (NoSuchAlgorithmException e) {
			cacheKey=String.valueOf(user.hashCode());
		}
		String newCacheKey=cacheKey.substring(0, 6);
		return newCacheKey;
	}
	private static String bytesToHexString(byte[] bytes){
		StringBuffer sbBuffer=new StringBuffer();
		for(int i=0;i<bytes.length;i++){
			String hex=Integer.toHexString(0xFF & bytes[i]);
			if(hex.length()==1){
				sbBuffer.append('0');
			}
			sbBuffer.append(hex);
		}
		return sbBuffer.toString();
	}
}