fix: resolve PR #120 review comments — exact token assertions and deterministic fuzz

- Use exact token_id/sell_token_id/buy_token_id byte assertions instead
  of non-empty checks in Exchange and Market servlet tests
- Add account_id byte assertion in SetAccountIdServletTest
- Switch fuzz test from non-deterministic SecureRandom to seeded Random
  for reproducible CI failures

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: halibobo1205

framework/src/test/java/org/tron/core/services/http/ExchangeCreateServletTest.java

@@ -48,8 +48,10 @@ && addressEquals(((ExchangeCreateContract) c)
                 .getOwnerAddress(), ownerAddr)
             && ((ExchangeCreateContract) c).getFirstTokenBalance() == 100
             && ((ExchangeCreateContract) c).getSecondTokenBalance() == 200
-            && !((ExchangeCreateContract) c).getFirstTokenId().isEmpty()
-            && !((ExchangeCreateContract) c).getSecondTokenId().isEmpty()),
+            && ((ExchangeCreateContract) c)
+                .getFirstTokenId().toStringUtf8().equals("_")
+            && ((ExchangeCreateContract) c)
+                .getSecondTokenId().toStringUtf8().equals("a")),
         eq(ContractType.ExchangeCreateContract));
     assertTransactionResponse(response);
   }

framework/src/test/java/org/tron/core/services/http/ExchangeInjectServletTest.java

@@ -48,7 +48,8 @@ && addressEquals(((ExchangeContract.ExchangeInjectContract) c)
                 .getOwnerAddress(), ownerAddr)
             && ((ExchangeContract.ExchangeInjectContract) c).getExchangeId() == 1
             && ((ExchangeContract.ExchangeInjectContract) c).getQuant() == 100
-            && !((ExchangeContract.ExchangeInjectContract) c).getTokenId().isEmpty()),
+            && ((ExchangeContract.ExchangeInjectContract) c)
+                .getTokenId().toStringUtf8().equals("_")),
         eq(Protocol.Transaction.Contract.ContractType.ExchangeInjectContract));
     assertTransactionResponse(response);
   }

framework/src/test/java/org/tron/core/services/http/ExchangeTransactionServletTest.java

@@ -50,7 +50,8 @@ && addressEquals(((ExchangeContract.ExchangeTransactionContract) c)
             && ((ExchangeContract.ExchangeTransactionContract) c).getExchangeId() == 1
             && ((ExchangeContract.ExchangeTransactionContract) c).getQuant() == 100
             && ((ExchangeContract.ExchangeTransactionContract) c).getExpected() == 10
-            && !((ExchangeContract.ExchangeTransactionContract) c).getTokenId().isEmpty()),
+            && ((ExchangeContract.ExchangeTransactionContract) c)
+                .getTokenId().toStringUtf8().equals("_")),
         eq(Protocol.Transaction.Contract.ContractType.ExchangeTransactionContract));
     assertTransactionResponse(response);
   }

framework/src/test/java/org/tron/core/services/http/ExchangeWithdrawServletTest.java

@@ -48,7 +48,8 @@ && addressEquals(((ExchangeContract.ExchangeWithdrawContract) c)
                 .getOwnerAddress(), ownerAddr)
             && ((ExchangeContract.ExchangeWithdrawContract) c).getExchangeId() == 1
             && ((ExchangeContract.ExchangeWithdrawContract) c).getQuant() == 50
-            && !((ExchangeContract.ExchangeWithdrawContract) c).getTokenId().isEmpty()),
+            && ((ExchangeContract.ExchangeWithdrawContract) c)
+                .getTokenId().toStringUtf8().equals("_")),
         eq(Protocol.Transaction.Contract.ContractType.ExchangeWithdrawContract));
     assertTransactionResponse(response);
   }

framework/src/test/java/org/tron/core/services/http/MarketSellAssetServletTest.java

@@ -49,8 +49,10 @@ && addressEquals(((MarketContract.MarketSellAssetContract) c)
                 .getOwnerAddress(), ownerAddr)
             && ((MarketContract.MarketSellAssetContract) c).getSellTokenQuantity() == 100
             && ((MarketContract.MarketSellAssetContract) c).getBuyTokenQuantity() == 200
-            && !((MarketContract.MarketSellAssetContract) c).getSellTokenId().isEmpty()
-            && !((MarketContract.MarketSellAssetContract) c).getBuyTokenId().isEmpty()),
+            && ((MarketContract.MarketSellAssetContract) c)
+                .getSellTokenId().toStringUtf8().equals("_")
+            && ((MarketContract.MarketSellAssetContract) c)
+                .getBuyTokenId().toStringUtf8().equals("`")),
         eq(Protocol.Transaction.Contract.ContractType.MarketSellAssetContract));
     assertTransactionResponse(response);
   }

framework/src/test/java/org/tron/core/services/http/SetAccountIdServletTest.java

@@ -42,7 +42,9 @@ public void testSetAccountId() throws Exception {
     verify(wallet).createTransactionCapsule(
         argThat(c -> c instanceof AccountContract.SetAccountIdContract
             && addressEquals(((AccountContract.SetAccountIdContract) c)
-                .getOwnerAddress(), ownerAddr)),
+                .getOwnerAddress(), ownerAddr)
+            && ((AccountContract.SetAccountIdContract) c)
+                .getAccountId().toStringUtf8().equals("aaaabbbb")),
         eq(Protocol.Transaction.Contract.ContractType.SetAccountIdContract));
     assertTransactionResponse(response);
   }

framework/src/test/java/org/tron/json/JsonCompatibilityFuzzTest.java

@@ -9,7 +9,7 @@
 
 import java.math.BigDecimal;
 import java.math.BigInteger;
-import java.security.SecureRandom;
+
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
@@ -29,7 +29,8 @@
 public class JsonCompatibilityFuzzTest {
 
   private static final int FUZZ_ROUNDS = 500;
-  private static final SecureRandom RNG = new SecureRandom();
+  private static final long SEED = 20260404L;
+  private static final Random RNG = new Random(SEED);
 
   // -------------------------------------------------------------------------
   // 1. JSON.parse — must throw on invalid JSON, return non-null on valid