refactor ExchangeCreateServlet post code

Author: M-blockcoder

crypto/src/main/java/org/tron/common/crypto/Hash.java

@@ -120,21 +120,7 @@ public static byte[] sha3(byte[] input, int start, int length) {
       throw new RuntimeException(e);
     }
   }
-
-  public static byte[] sha512(byte[] input) {
-    MessageDigest digest;
-    try {
-      digest = MessageDigest.getInstance(HASH_512_ALGORITHM_NAME,
-          CRYPTO_PROVIDER);
-      digest.update(input);
-      return digest.digest();
-    } catch (NoSuchAlgorithmException e) {
-      logger.error(ALGORITHM_NOT_FOUND, e);
-      throw new RuntimeException(e);
-    }
-  }
-
-
+  
   public static byte[] encodeElement(byte[] srcData) {
 
     // [0x80]

framework/src/main/java/org/tron/core/services/http/ExchangeCreateServlet.java

@@ -22,18 +22,16 @@ public class ExchangeCreateServlet extends RateLimiterServlet {
 
   protected void doPost(HttpServletRequest request, HttpServletResponse response) {
     try {
-      String contract = request.getReader().lines()
-          .collect(Collectors.joining(System.lineSeparator()));
-      Util.checkBodySize(contract);
-      boolean visible = Util.getVisiblePost(contract);
+      PostParams params = PostParams.getPostParams(request);
       ExchangeCreateContract.Builder build = ExchangeCreateContract.newBuilder();
-      JsonFormat.merge(contract, build, visible);
+      JsonFormat.merge(params.getParams(), build, params.isVisible());
       Transaction tx = wallet
           .createTransactionCapsule(build.build(), ContractType.ExchangeCreateContract)
           .getInstance();
-      JSONObject jsonObject = JSONObject.parseObject(contract);
+      JSONObject jsonObject = JSONObject.parseObject(params.getParams());
       tx = Util.setTransactionPermissionId(jsonObject, tx);
-      response.getWriter().println(Util.printCreateTransaction(tx, visible));
+      response.getWriter().println(Util
+          .printCreateTransaction(tx, params.isVisible()));
     } catch (Exception e) {
       Util.processError(e, response);
     }