ObjectMapper configuration should apply when pretty printing

Since the pretty mapper is deprecated, any customization of the object mapper should be used when pretty printing with Json.encodePrettily.

And then it is no longer necessary to create the pretty mapper config by default, so we can lazily create it.

Signed-off-by: Thomas Segismont <tsegismont@gmail.com>

src/main/java/io/vertx/core/json/jackson/DatabindCodec.java

@@ -27,29 +27,28 @@
 import java.io.InputStream;
 import java.util.List;
 import java.util.Map;
+import java.util.concurrent.atomic.AtomicReference;
 
 /**
  * @author <a href="mailto:julien@julienviet.com">Julien Viet</a>
  */
 public class DatabindCodec extends JacksonCodec {
 
   private static final ObjectMapper mapper = new ObjectMapper();
-  private static final ObjectMapper prettyMapper = new ObjectMapper();
+  private static final AtomicReference<ObjectMapper> prettyMapper = new AtomicReference<>();
 
   static {
-    initialize();
+    initialize(mapper, false);
   }
 
-  private static void initialize() {
+  private static void initialize(ObjectMapper om, boolean prettyPrint) {
     // Non-standard JSON but we allow C style comments in our JSON
-    mapper.configure(JsonParser.Feature.ALLOW_COMMENTS, true);
-
-    prettyMapper.configure(JsonParser.Feature.ALLOW_COMMENTS, true);
-    prettyMapper.configure(SerializationFeature.INDENT_OUTPUT, true);
-
+    om.configure(JsonParser.Feature.ALLOW_COMMENTS, true);
+    if (prettyPrint) {
+      om.configure(SerializationFeature.INDENT_OUTPUT, true);
+    }
     VertxModule module = new VertxModule();
-    mapper.registerModule(module);
-    prettyMapper.registerModule(module);
+    om.registerModule(module);
   }
 
   /**
@@ -65,7 +64,13 @@ public static ObjectMapper mapper() {
    */
   @Deprecated
   public static ObjectMapper prettyMapper() {
-    return prettyMapper;
+    ObjectMapper pm = prettyMapper.get();
+    if (pm != null) {
+      return pm;
+    }
+    pm = new ObjectMapper();
+    initialize(pm, true);
+    return prettyMapper.compareAndSet(null, pm) ? pm : prettyMapper.get();
   }
 
   @Override
@@ -157,8 +162,13 @@ private static <T> T fromParser(JsonParser parser, TypeReference<T> type) throws
   @Override
   public String toString(Object object, boolean pretty) throws EncodeException {
     try {
-      ObjectMapper mapper = pretty ? DatabindCodec.prettyMapper : DatabindCodec.mapper;
-      return mapper.writeValueAsString(object);
+      String result;
+      if (pretty) {
+        result = mapper.writerWithDefaultPrettyPrinter().writeValueAsString(object);
+      } else {
+        result = mapper.writeValueAsString(object);
+      }
+      return result;
     } catch (Exception e) {
       throw new EncodeException("Failed to encode as JSON: " + e.getMessage());
     }
@@ -167,8 +177,13 @@ public String toString(Object object, boolean pretty) throws EncodeException {
   @Override
   public Buffer toBuffer(Object object, boolean pretty) throws EncodeException {
     try {
-      ObjectMapper mapper = pretty ? DatabindCodec.prettyMapper : DatabindCodec.mapper;
-      return Buffer.buffer(mapper.writeValueAsBytes(object));
+      byte[] result;
+      if (pretty) {
+        result = mapper.writerWithDefaultPrettyPrinter().writeValueAsBytes(object);
+      } else {
+        result = mapper.writeValueAsBytes(object);
+      }
+      return Buffer.buffer(result);
     } catch (Exception e) {
       throw new EncodeException("Failed to encode as JSON: " + e.getMessage());
     }

src/test/java/io/vertx/core/json/JacksonDatabindTest.java

@@ -14,6 +14,9 @@
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.core.type.TypeReference;
 import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.SerializationConfig;
+import com.fasterxml.jackson.databind.SerializationFeature;
+import io.vertx.core.ThreadingModel;
 import io.vertx.core.buffer.Buffer;
 import io.vertx.core.json.jackson.DatabindCodec;
 import io.vertx.core.json.jackson.JacksonCodec;
@@ -108,4 +111,18 @@ private static class Pojo {
     @JsonProperty
     byte[] bytes;
   }
+
+  @Test
+  public void testObjectMapperConfigAppliesToPrettyPrinting() {
+    ObjectMapper om = DatabindCodec.mapper();
+    SerializationConfig sc = om.getSerializationConfig();
+    assertNotNull(sc);
+    try {
+      om.setConfig(sc.with(SerializationFeature.WRITE_ENUMS_USING_INDEX));
+      ThreadingModel vt = ThreadingModel.VIRTUAL_THREAD;
+      assertEquals(Json.encode(vt), Json.encodePrettily(vt));
+    } finally {
+      om.setConfig(sc);
+    }
+  }
 }