Fix Java ulong enum literal generation

java/src/test/java/JavaTest.java

@@ -87,6 +87,23 @@ public void TestEnums() {
     assertThat(Any.name(Any.Monster)).isEqualTo("Monster");
   }
 
+  @org.junit.Test
+  public void TestUlongEnums() {
+    assertThat(Condition.Empty).isEqualTo(0L);
+    assertThat(Condition.GreaterThanEqual)
+        .isEqualTo(Long.parseUnsignedLong("34F605C97C571896", 16));
+    assertThat(Condition.LessThanEqual)
+        .isEqualTo(Long.parseUnsignedLong("488B1F9FBC949365", 16));
+    assertThat(Condition.NotEqual)
+        .isEqualTo(Long.parseUnsignedLong("88C99E99F1FC6C55", 16));
+    assertThat(Condition.Equal)
+        .isEqualTo(Long.parseUnsignedLong("B763CBE88B6F844F", 16));
+    assertThat(Condition.None)
+        .isEqualTo(Long.parseUnsignedLong("CBF29CE484222645", 16));
+    assertThat(Condition.Between)
+        .isEqualTo(Long.parseUnsignedLong("E5E34D77DC75E2EF", 16));
+  }
+
   static void TestBuffer(ByteBuffer bb) {
     assertThat(Monster.MonsterBufferHasIdentifier(bb)).isEqualTo(true);
 

scripts/generate_code.py

@@ -481,6 +481,9 @@ def glob(path, pattern):
 dictionary_lookup_schema = "dictionary_lookup.fbs"
 flatc(["--java", "--kotlin"], schema=dictionary_lookup_schema)
 
+# Java ulong enum generation test
+flatc(["--java"], schema="java_ulong_enum_test.fbs")
+
 # Swift Tests
 swift_prefix = "swift/Tests/Flatbuffers"
 flatc(

src/idl_gen_java.cpp

@@ -419,6 +419,15 @@ class JavaGenerator : public BaseGenerator {
     return GenDefaultValue(field);
   }
 
+  std::string GenEnumValue(const EnumDef& enum_def, const EnumVal& enum_val) const {
+    auto value = enum_def.ToString(enum_val);
+    if (enum_def.underlying_type.base_type == BASE_TYPE_ULONG) {
+      const uint64_t unsigned_value = StringToUInt(value.c_str());
+      return NumToString(static_cast<int64_t>(unsigned_value));
+    }
+    return value;
+  }
+
   void GenEnum(EnumDef& enum_def, std::string& code) const {
     if (enum_def.generated) return;
 
@@ -445,7 +454,7 @@ class JavaGenerator : public BaseGenerator {
       code += GenTypeBasic(DestinationType(enum_def.underlying_type, false));
       code += " ";
       code += namer_.Variant(ev) + " = ";
-      code += enum_def.ToString(ev);
+      code += GenEnumValue(enum_def, ev);
       if (enum_def.underlying_type.base_type == BASE_TYPE_UINT ||
           enum_def.underlying_type.base_type == BASE_TYPE_LONG ||
           enum_def.underlying_type.base_type == BASE_TYPE_ULONG) {

tests/MyGame/Example/Condition.java

@@ -0,0 +1,16 @@
+// automatically generated by the FlatBuffers compiler, do not modify
+
+package MyGame.Example;
+
+@SuppressWarnings("unused")
+public final class Condition {
+  private Condition() { }
+  public static final long Empty = 0L;
+  public static final long GreaterThanEqual = 3816244097175722134L;
+  public static final long LessThanEqual = 5227306563417707365L;
+  public static final long NotEqual = -8590160430205473707L;
+  public static final long Equal = -5232114142442191793L;
+  public static final long None = -3750763034362894779L;
+  public static final long Between = -1881575042115575057L;
+}
+

tests/java_ulong_enum_test.fbs

@@ -0,0 +1,11 @@
+namespace MyGame.Example;
+
+enum Condition : ulong {
+  Empty = 0,
+  GreaterThanEqual = 0x34F605C97C571896,
+  LessThanEqual = 0x488B1F9FBC949365,
+  NotEqual = 0x88C99E99F1FC6C55,
+  Equal = 0xB763CBE88B6F844F,
+  None = 0xCBF29CE484222645,
+  Between = 0xE5E34D77DC75E2EF
+}