Fix: Keep acronyms uppercase in Java enum constants (#2850)

packages/quicktype-core/src/language/Java/utils.ts

@@ -44,13 +44,15 @@ export function javaNameStyle(
         upperUnderscore
             ? allUpperWordStyle
             : startWithUpper
-              ? firstUpperWordStyle
-              : allLowerWordStyle,
+                ? firstUpperWordStyle
+                : allLowerWordStyle,
         upperUnderscore ? allUpperWordStyle : firstUpperWordStyle,
         upperUnderscore || startWithUpper
             ? allUpperWordStyle
             : allLowerWordStyle,
-        acronymsStyle,
+        // For UPPER_UNDERSCORE style (Java enum constants), always use allUpperWordStyle for acronyms
+        // to maintain consistency with the naming convention (e.g., XXX_SPA_XXX)
+        upperUnderscore ? allUpperWordStyle : acronymsStyle,
         upperUnderscore ? "_" : "",
         isStartCharacter,
     );

test/fixtures/java/src/main/java/io/quicktype/MessageCode.java

@@ -0,0 +1,42 @@
+package io.quicktype;
+
+import java.io.IOException;
+import com.fasterxml.jackson.annotation.*;
+
+public class MessageCode {
+    private Code code;
+
+    @JsonProperty("code")
+    public Code getCode() {
+        return code;
+    }
+
+    @JsonProperty("code")
+    public void setCode(Code value) {
+        this.code = value;
+    }
+
+    public enum Code {
+        MULTI_SPA_IN_GROUP_REJECTED, SOME_OTHER_VALUE;
+
+        @JsonValue
+        public String toValue() {
+            switch (this) {
+                case MULTI_SPA_IN_GROUP_REJECTED:
+                    return "MULTI_SPA_IN_GROUP_REJECTED";
+                case SOME_OTHER_VALUE:
+                    return "SOME_OTHER_VALUE";
+            }
+            return null;
+        }
+
+        @JsonCreator
+        public static Code forValue(String value) throws IOException {
+            if (value.equals("MULTI_SPA_IN_GROUP_REJECTED"))
+                return MULTI_SPA_IN_GROUP_REJECTED;
+            if (value.equals("SOME_OTHER_VALUE"))
+                return SOME_OTHER_VALUE;
+            throw new IOException("Cannot deserialize Code");
+        }
+    }
+}

test/inputs/json/priority/enum-spa.json

@@ -0,0 +1,10 @@
+{
+  "$schema": "http://json-schema.org/draft-07/schema#",
+  "type": "object",
+  "properties": {
+    "code": {
+      "type": "string",
+      "enum": ["SOME_OTHER_VALUE", "MULTI_SPA_IN_GROUP_REJECTED"]
+    }
+  }
+}