java实现HMACSHA256加密签名

java实现HMACSHA256加密签名，需要按照字典排序的朋友可以用
SortedMap<Object, Object> message=new TreeMap<Object, Object>();进行排序后在加密。
/** 

* @version 1.0

 * @project： autoTrade 

* @author： QC班长 

* @date：2017/8/3 

* @time：10:17 

*/

import javax.crypto.Mac;

import javax.crypto.spec.SecretKeySpec;

import java.util.*;

public class HMACSHA256 { 

      //   SECRET KEY    

private final static String secret_key = "ndE2jdZNFixH9G6Aidsfyf7lYT3PxW";  

  /**     

  * 将加密后的字节数组转换成字符串   

  *    

  * @param b 字节数组    

  * @return 字符串     

  */   

 private static String byteArrayToHexString(byte[] b) {  

      StringBuilder hs = new StringBuilder();     

      String stmp;      

  for (int n = 0; b!=null && n < b.length; n++) {   

         stmp = Integer.toHexString(b[n] & 0XFF);    

         if (stmp.length() == 1)           

         hs.append('0');      

         hs.append(stmp);    

    }      

   return hs.toString().toLowerCase();   

 }   

 /**   

  * sha256_HMAC加密    

  * @param message 消息   

  * @param secret  秘钥 

  * @return 加密后字符串  

  */  

  private static String sha256_HMAC(String message, String secret) {     

   String hash = "";      

   try {         

       Mac sha256_HMAC = Mac.getInstance("HmacSHA256");     

       SecretKeySpec secret_key = new SecretKeySpec(secret.getBytes(), "HmacSHA256");      

       sha256_HMAC.init(secret_key);       

       byte[] bytes = sha256_HMAC.doFinal(message.getBytes());   

       hash = byteArrayToHexString(bytes);         

       System.out.println(hash);    

       } catch (Exception e) {     

       System.out.println("Error HmacSHA256 ===========" + e.getMessage());   

     }       

    return hash;   

   }     

 }