ツールクラスのappSecret,timeStamp,nonceの3つのパラメータを辞書ソートしてSHA 1を暗号化しsignatureを得る.

 public class SortAndEncryptUtils {
    public static String sortAndEncrypt(String appSecret, String timestamp, String nonce) {
        ArrayList list = new ArrayList();
        list.add(appSecret);
        list.add(timestamp);
        list.add(nonce);
        Collections.sort(list);
        return DigestUtils.shaHex(list.get(0) + list.get(1) + list.get(2));
    }
} 

String appSecret = "xxxxxxxxxxxxxxxxxxxxxxxxxxxxx";  //appSecret
String timestamp = String.valueOf(System.currentTimeMillis() / 1000); //       10    
String nonce = ""; //   
//          
for (int i = 0; i < 3; i++) { nonce += String.valueOf((int) (Math.random() * 10)); }
//        SHA1    signature。
String signature = SortAndEncryptUtils.sortAndEncrypt(appSecret, timestamp, nonce);