feat(api): support int64_as_string parameter for GET requests

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

@@ -19,7 +19,10 @@ public class GetBurnTrxServlet extends RateLimiterServlet {
   protected void doGet(HttpServletRequest request, HttpServletResponse response) {
     try {
       long value = manager.getDynamicPropertiesStore().getBurnTrxAmount();
-      response.getWriter().println("{\"burnTrxAmount\": " + value + "}");
+      String out = JsonFormat.isInt64AsString()
+          ? "{\"burnTrxAmount\": \"" + value + "\"}"
+          : "{\"burnTrxAmount\": " + value + "}";
+      response.getWriter().println(out);
     } catch (Exception e) {
       logger.error("", e);
       try {

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

@@ -19,7 +19,10 @@ public class GetPendingSizeServlet extends RateLimiterServlet {
   protected void doGet(HttpServletRequest request, HttpServletResponse response) {
     try {
       long value = manager.getPendingSize();
-      response.getWriter().println("{\"pendingSize\": " + value + "}");
+      String out = JsonFormat.isInt64AsString()
+          ? "{\"pendingSize\": \"" + value + "\"}"
+          : "{\"pendingSize\": " + value + "}";
+      response.getWriter().println(out);
     } catch (Exception e) {
       logger.error("", e);
       try {

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

@@ -24,7 +24,10 @@ protected void doGet(HttpServletRequest request, HttpServletResponse response) {
       if (address != null) {
         value = manager.getMortgageService().queryReward(address);
       }
-      response.getWriter().println("{\"reward\": " + value + "}");
+      String out = JsonFormat.isInt64AsString()
+          ? "{\"reward\": \"" + value + "\"}"
+          : "{\"reward\": " + value + "}";
+      response.getWriter().println(out);
     } catch (DecoderException | IllegalArgumentException e) {
       try {
         response.getWriter()

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

@@ -40,6 +40,9 @@ protected void doPost(HttpServletRequest request, HttpServletResponse response)
 
   private void fillResponse(long num, HttpServletResponse response) throws IOException {
     long count = wallet.getTransactionCountByBlockNum(num);
-    response.getWriter().println("{\"count\": " + count + "}");
+    String out = JsonFormat.isInt64AsString()
+        ? "{\"count\": \"" + count + "\"}"
+        : "{\"count\": " + count + "}";
+    response.getWriter().println(out);
   }
 }

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

@@ -90,6 +90,41 @@ public class JsonFormat {
       BalanceContract.TransactionBalanceTrace.class
   );
 
+  /**
+   * Thread-local flag controlling whether int64/uint64 fields are serialized as JSON strings.
+   * Set via {@link #setInt64AsString(boolean)} early in request handling and cleared via
+   * {@link #clearInt64AsString()} in a finally block. Centralized in
+   * {@code RateLimiterServlet.service} for GET requests. Does not support nested scopes.
+   */
+  private static final ThreadLocal<Boolean> INT64_AS_STRING =
+      ThreadLocal.withInitial(() -> false);
+
+  /**
+   * Set whether int64/uint64 protobuf fields are serialized as quoted JSON strings to avoid
+   * precision loss in clients whose native number type cannot safely represent integers above
+   * 2^53 - 1 (e.g. JavaScript). Must be paired with {@link #clearInt64AsString()} in a
+   * finally block.
+   */
+  public static void setInt64AsString(boolean enabled) {
+    INT64_AS_STRING.set(enabled);
+  }
+
+  /**
+   * Clear the int64-as-string thread-local. Always call from a finally block to avoid
+   * polluting subsequent requests on the same (reused) thread.
+   */
+  public static void clearInt64AsString() {
+    INT64_AS_STRING.remove();
+  }
+
+  /**
+   * Whether the current thread is in int64-as-string mode. Used by servlets that build
+   * JSON literals manually (i.e. do not go through {@link #printToString}).
+   */
+  public static boolean isInt64AsString() {
+    return INT64_AS_STRING.get();
+  }
+
   /**
    * Outputs a textual representation of the Protocol Message supplied into the parameter output.
    * (This representation is the new version of the classic "ProtocolPrinter" output from the
@@ -340,26 +375,41 @@ private static void printFieldValue(FieldDescriptor field, Object value,
       throws IOException {
     switch (field.getType()) {
       case INT32:
-      case INT64:
       case SINT32:
-      case SINT64:
       case SFIXED32:
-      case SFIXED64:
       case FLOAT:
       case DOUBLE:
       case BOOL:
         // Good old toString() does what we want for these types.
         generator.print(value.toString());
         break;
 
+      case INT64:
+      case SINT64:
+      case SFIXED64:
+        if (INT64_AS_STRING.get()) {
+          generator.print("\"");
+          generator.print(value.toString());
+          generator.print("\"");
+        } else {
+          generator.print(value.toString());
+        }
+        break;
+
       case UINT32:
       case FIXED32:
         generator.print(unsignedToString((Integer) value));
         break;
 
       case UINT64:
       case FIXED64:
-        generator.print(unsignedToString((Long) value));
+        if (INT64_AS_STRING.get()) {
+          generator.print("\"");
+          generator.print(unsignedToString((Long) value));
+          generator.print("\"");
+        } else {
+          generator.print(unsignedToString((Long) value));
+        }
         break;
 
       case STRING:

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

@@ -102,6 +102,12 @@ protected void service(HttpServletRequest req, HttpServletResponse resp)
     String contextPath = req.getContextPath();
     String url = Strings.isNullOrEmpty(req.getServletPath())
         ? MetricLabels.UNDEFINED : contextPath + req.getServletPath();
+    // int64_as_string is honored only on GET requests (URL query). POST is intentionally
+    // unsupported because reading the body here would consume request.getReader() and
+    // break downstream servlets that read it themselves.
+    if ("GET".equalsIgnoreCase(req.getMethod())) {
+      JsonFormat.setInt64AsString(Util.getInt64AsString(req));
+    }
     try {
       resp.setContentType("application/json; charset=utf-8");
 
@@ -119,6 +125,10 @@ protected void service(HttpServletRequest req, HttpServletResponse resp)
     } catch (Exception unexpected) {
       logger.error("Http Api {}, Method:{}. Error：", url, req.getMethod(), unexpected);
     } finally {
+      // CRITICAL: this clear pairs with the setInt64AsString call above. Removing it
+      // will leak int64_as_string state across requests on reused Tomcat threads,
+      // producing intermittent quoted/unquoted output that is very hard to debug.
+      JsonFormat.clearInt64AsString();
       if (rateLimiter instanceof IPreemptibleRateLimiter && acquireResource) {
         ((IPreemptibleRateLimiter) rateLimiter).release();
       }

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

@@ -66,6 +66,7 @@ public class Util {
 
   public static final String PERMISSION_ID = "Permission_id";
   public static final String VISIBLE = "visible";
+  public static final String INT64_AS_STRING = "int64_as_string";
   public static final String TRANSACTION = "transaction";
   public static final String TRANSACTION_EXTENSION = "transactionExtension";
   public static final String VALUE = "value";
@@ -346,6 +347,20 @@ public static boolean existVisible(final HttpServletRequest request) {
     return Objects.nonNull(request.getParameter(VISIBLE));
   }
 
+  /**
+   * Read int64_as_string from URL query parameter. Mirrors
+   * {@link #getVisible(HttpServletRequest)}. The flag is honored only on GET requests
+   * (read by {@link RateLimiterServlet#service}); POST requests do not support it
+   * because that would require caching the request body to allow re-reading by
+   * downstream servlets.
+   */
+  public static boolean getInt64AsString(final HttpServletRequest request) {
+    if (StringUtil.isNotBlank(request.getParameter(INT64_AS_STRING))) {
+      return Boolean.parseBoolean(request.getParameter(INT64_AS_STRING));
+    }
+    return false;
+  }
+
   public static boolean getVisiblePost(final String input) {
     boolean visible = false;
     if (StringUtil.isNotBlank(input)) {