CLDR-18475 correct CLDRLocale serialization (#4614)

Author: srl295

tools/cldr-apps/src/main/java/org/unicode/cldr/web/util/JsonUtil.java

@@ -6,32 +6,41 @@
 import com.google.gson.stream.JsonReader;
 import com.google.gson.stream.JsonWriter;
 import java.io.IOException;
+import org.unicode.cldr.util.CLDRLocale;
 
 /** utilities for JSON */
 public class JsonUtil {
 
+    private abstract static class WriteOnlyTypeAdapter<T> extends TypeAdapter<T> {
+        @Override
+        public T read(JsonReader in) throws IOException {
+            // write only
+            throw new UnsupportedOperationException("Unimplemented method 'read' - write only");
+        }
+    }
+
+    private static final class JSONStringTypeAdapter extends WriteOnlyTypeAdapter<JSONString> {
+        @Override
+        public void write(JsonWriter out, JSONString value) throws IOException {
+            out.jsonValue(value.toJSONString());
+        }
+    }
+
+    /** type adapter that uses Object.toString() rather than serializing object contents */
+    private static final class ToStringTypeAdapter<T> extends WriteOnlyTypeAdapter<T> {
+        @Override
+        public void write(JsonWriter out, T value) throws IOException {
+            out.value(value.toString());
+        }
+    }
+
     private static final Gson gson =
             new GsonBuilder()
                     .setDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSS'Z'")
                     .setPrettyPrinting()
-                    .registerTypeHierarchyAdapter(
-                            JSONString.class,
-                            new TypeAdapter<JSONString>() {
-
-                                @Override
-                                public void write(JsonWriter out, JSONString value)
-                                        throws IOException {
-                                    out.jsonValue(value.toJSONString());
-                                }
-
-                                @Override
-                                public JSONString read(JsonReader in) throws IOException {
-                                    // write only
-                                    // TODO Auto-generated method stub
-                                    throw new UnsupportedOperationException(
-                                            "Unimplemented method 'read' - write only");
-                                }
-                            })
+                    // register any classes that need toString() for serialization
+                    .registerTypeHierarchyAdapter(CLDRLocale.class, new ToStringTypeAdapter<>())
+                    .registerTypeHierarchyAdapter(JSONString.class, new JSONStringTypeAdapter())
                     .create();
 
     public static Gson gson() {