perf: consolidate duplicate ObjectMapper instances into SerializerFactory

src/main/java/com/aws/greengrass/authorization/AuthorizationPolicyParser.java

@@ -12,11 +12,10 @@
 import com.aws.greengrass.logging.api.Logger;
 import com.aws.greengrass.logging.impl.LogManager;
 import com.aws.greengrass.util.Coerce;
+import com.aws.greengrass.util.SerializerFactory;
 import com.aws.greengrass.util.Utils;
 import com.fasterxml.jackson.core.type.TypeReference;
-import com.fasterxml.jackson.databind.MapperFeature;
 import com.fasterxml.jackson.databind.ObjectMapper;
-import com.fasterxml.jackson.databind.json.JsonMapper;
 
 import java.io.IOException;
 import java.util.ArrayList;
@@ -30,8 +29,7 @@
 
 public final class AuthorizationPolicyParser {
     private static final Logger logger = LogManager.getLogger(AuthorizationPolicyParser.class);
-    private static final ObjectMapper OBJECT_MAPPER =
-            JsonMapper.builder().configure(MapperFeature.ACCEPT_CASE_INSENSITIVE_PROPERTIES, true).build();
+    private static final ObjectMapper OBJECT_MAPPER = SerializerFactory.getCaseInsensitiveJsonObjectMapper();
     /**
      * Given a kernel object, construct and return a map of AuthorizationPolicy objects that may exist,
      * grouped into lists of the same destination component.

src/main/java/com/aws/greengrass/builtin/services/pubsub/PubSubIPCEventStreamAgent.java

@@ -11,6 +11,7 @@
 import com.aws.greengrass.logging.api.Logger;
 import com.aws.greengrass.logging.impl.LogManager;
 import com.aws.greengrass.util.OrderedExecutorService;
+import com.aws.greengrass.util.SerializerFactory;
 import com.aws.greengrass.util.Utils;
 import com.fasterxml.jackson.core.JsonProcessingException;
 import com.fasterxml.jackson.databind.ObjectMapper;
@@ -49,7 +50,7 @@ public class PubSubIPCEventStreamAgent {
     private static final String MQTT_SINGLELEVEL_WILDCARD = "+";
     private static final String MQTT_MULTILEVEL_WILDCARD = "#";
     private static final String GLOB_WILDCARD = "*";
-    private static final ObjectMapper SERIALIZER = new ObjectMapper();
+    private static final ObjectMapper SERIALIZER = SerializerFactory.getJsonObjectMapper();
     @Getter(AccessLevel.PACKAGE)
     private final SubscriptionTrie<SubscriptionCallback> listeners = new SubscriptionTrie<>();
 

src/main/java/com/aws/greengrass/componentmanager/KernelConfigResolver.java

@@ -26,12 +26,11 @@
 import com.aws.greengrass.util.Coerce;
 import com.aws.greengrass.util.CrashableFunction;
 import com.aws.greengrass.util.NucleusPaths;
+import com.aws.greengrass.util.SerializerFactory;
 import com.aws.greengrass.util.Utils;
 import com.fasterxml.jackson.core.JsonPointer;
 import com.fasterxml.jackson.databind.JsonNode;
-import com.fasterxml.jackson.databind.MapperFeature;
 import com.fasterxml.jackson.databind.ObjectMapper;
-import com.fasterxml.jackson.databind.SerializationFeature;
 import com.vdurmont.semver4j.Semver;
 
 import java.io.IOException;
@@ -89,9 +88,7 @@ public class KernelConfigResolver {
             Pattern.compile("\\{([.\\w-]+):([.\\w-]+):([^:}]*)}");
     // https://tools.ietf.org/html/rfc6901#section-5
     private static final String JSON_POINTER_WHOLE_DOC = "";
-    private static final ObjectMapper MAPPER = new ObjectMapper()
-            .enable(MapperFeature.SORT_PROPERTIES_ALPHABETICALLY)
-            .enable(SerializationFeature.ORDER_MAP_ENTRIES_BY_KEYS);
+    private static final ObjectMapper MAPPER = SerializerFactory.getSortedJsonObjectMapper();
     // Map from Namespace -> Key -> Function which returns the replacement value
     private final Map<String, Map<String, CrashableFunction<ComponentIdentifier, String, IOException>>>
             systemParameters = new HashMap<>();

src/main/java/com/aws/greengrass/ipc/IPCEventStreamService.java

@@ -14,9 +14,9 @@
 import com.aws.greengrass.logging.api.Logger;
 import com.aws.greengrass.logging.impl.LogManager;
 import com.aws.greengrass.util.Coerce;
+import com.aws.greengrass.util.SerializerFactory;
 import com.aws.greengrass.util.Utils;
 import com.aws.greengrass.util.platforms.Platform;
-import com.fasterxml.jackson.databind.DeserializationFeature;
 import com.fasterxml.jackson.databind.ObjectMapper;
 import software.amazon.awssdk.aws.greengrass.GreengrassCoreIPCService;
 import software.amazon.awssdk.aws.greengrass.GreengrassCoreIPCServiceModel;
@@ -40,9 +40,7 @@
 public class IPCEventStreamService implements Startable, Closeable {
     public static final long DEFAULT_STREAM_MESSAGE_TIMEOUT_SECONDS = 5;
     public static final int DEFAULT_PORT_NUMBER = 8033;
-    private static final ObjectMapper OBJECT_MAPPER =
-            new ObjectMapper().configure(DeserializationFeature.FAIL_ON_INVALID_SUBTYPE, false)
-                    .configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
+    private static final ObjectMapper OBJECT_MAPPER = SerializerFactory.getFailSafeJsonObjectMapper();
 
     public static final String NUCLEUS_DOMAIN_SOCKET_FILEPATH = "AWS_GG_NUCLEUS_DOMAIN_SOCKET_FILEPATH";
     public static final String NUCLEUS_DOMAIN_SOCKET_FILEPATH_FOR_COMPONENT =

src/main/java/com/aws/greengrass/telemetry/MetricsAggregator.java

@@ -14,6 +14,7 @@
 import com.aws.greengrass.telemetry.impl.TelemetryLoggerMessage;
 import com.aws.greengrass.telemetry.impl.config.TelemetryConfig;
 import com.aws.greengrass.util.Coerce;
+import com.aws.greengrass.util.SerializerFactory;
 import com.aws.greengrass.util.platforms.Platform;
 import com.fasterxml.jackson.core.JsonProcessingException;
 import com.fasterxml.jackson.databind.ObjectMapper;
@@ -34,7 +35,7 @@
 public class MetricsAggregator {
     public static final Logger logger = LogManager.getLogger(MetricsAggregator.class);
     protected static final String AGGREGATE_METRICS_FILE = "AggregateMetrics";
-    private static final ObjectMapper objectMapper = new ObjectMapper();
+    private static final ObjectMapper objectMapper = SerializerFactory.getJsonObjectMapper();
     private final MetricFactory metricFactory = new MetricFactory(AGGREGATE_METRICS_FILE);
 
     /**
@@ -269,7 +270,7 @@ protected Map<Long, List<AggregatedNamespaceData>> getMetricsToPublish(long last
         });
 
         try {
-            logger.atDebug().kv("metrics", new ObjectMapper().writeValueAsString(aggUploadMetrics))
+            logger.atDebug().kv("metrics", objectMapper.writeValueAsString(aggUploadMetrics))
                     .log("Preparing to upload metrics");
         } catch (JsonProcessingException e) {
             logger.atWarn().setCause(e).log("Could not convert aggregated metrics to json, continuing");

src/main/java/com/aws/greengrass/tes/CredentialRequestHandler.java

@@ -21,9 +21,9 @@
 import com.aws.greengrass.util.DefaultConcurrentHashMap;
 import com.aws.greengrass.util.LockFactory;
 import com.aws.greengrass.util.LockScope;
+import com.aws.greengrass.util.SerializerFactory;
 import com.aws.greengrass.util.exceptions.TLSAuthException;
 import com.fasterxml.jackson.core.JsonProcessingException;
-import com.fasterxml.jackson.databind.DeserializationFeature;
 import com.fasterxml.jackson.databind.JsonNode;
 import com.fasterxml.jackson.databind.ObjectMapper;
 import com.sun.net.httpserver.HttpExchange;
@@ -63,8 +63,7 @@ public class CredentialRequestHandler implements HttpHandler {
     private static final String SESSION_TOKEN_DOWNSTREAM_STR = "Token";
     private static final String EXPIRATION_UPSTREAM_STR = "expiration";
     private static final String EXPIRATION_DOWNSTREAM_STR = "Expiration";
-    private static final ObjectMapper OBJECT_MAPPER =
-            new ObjectMapper().configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, true);
+    private static final ObjectMapper OBJECT_MAPPER = SerializerFactory.getStrictJsonObjectMapper();
     public static final String AUTH_HEADER = "Authorization";
     public static final String IOT_CREDENTIALS_HTTP_VERB = "GET";
     public static final String SUPPORTED_REQUEST_VERB = "GET";

src/main/java/com/aws/greengrass/util/Coerce.java

@@ -23,7 +23,7 @@
 public final class Coerce {
     private static final Pattern SEPARATORS = Pattern.compile(" *, *");
     private static final Pattern unwrap = Pattern.compile(" *\\[ *(.*) *\\] *");
-    private static final ObjectMapper MAPPER = new ObjectMapper();
+    private static final ObjectMapper MAPPER = SerializerFactory.getJsonObjectMapper();
 
     private Coerce() {
     }

src/main/java/com/aws/greengrass/util/MqttChunkedPayloadPublisher.java

@@ -21,7 +21,7 @@
 public class MqttChunkedPayloadPublisher<T> {
     private static final Logger logger = LogManager.getLogger(MqttChunkedPayloadPublisher.class);
     private static final String topicKey = "topic";
-    private static final ObjectMapper SERIALIZER = new ObjectMapper();
+    private static final ObjectMapper SERIALIZER = SerializerFactory.getJsonObjectMapper();
     private final MqttClient mqttClient;
     @Setter
     private String updateTopic;

src/main/java/com/aws/greengrass/util/SerializerFactory.java

@@ -6,7 +6,10 @@
 package com.aws.greengrass.util;
 
 import com.fasterxml.jackson.databind.DeserializationFeature;
+import com.fasterxml.jackson.databind.MapperFeature;
 import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.SerializationFeature;
+import com.fasterxml.jackson.databind.json.JsonMapper;
 
 public final class SerializerFactory {
 
@@ -15,10 +18,52 @@ public final class SerializerFactory {
             new ObjectMapper().configure(DeserializationFeature.FAIL_ON_INVALID_SUBTYPE, false)
                     .configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
 
+    private static final ObjectMapper JSON_OBJECT_MAPPER = new ObjectMapper();
+
+    private static final ObjectMapper STRICT_JSON_OBJECT_MAPPER =
+            new ObjectMapper().configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, true);
+
+    private static final ObjectMapper CASE_INSENSITIVE_JSON_OBJECT_MAPPER =
+            JsonMapper.builder().configure(MapperFeature.ACCEPT_CASE_INSENSITIVE_PROPERTIES, true).build();
+
+    private static final ObjectMapper SORTED_JSON_OBJECT_MAPPER =
+            JsonMapper.builder()
+                    .enable(MapperFeature.SORT_PROPERTIES_ALPHABETICALLY)
+                    .enable(SerializationFeature.ORDER_MAP_ENTRIES_BY_KEYS)
+                    .build();
+
     public static ObjectMapper getFailSafeJsonObjectMapper() {
         return FAIL_SAFE_JSON_OBJECT_MAPPER;
     }
 
+    /**
+     * Get a default ObjectMapper with no special configuration.
+     */
+    public static ObjectMapper getJsonObjectMapper() {
+        return JSON_OBJECT_MAPPER;
+    }
+
+    /**
+     * Get an ObjectMapper that fails on unknown properties.
+     */
+    public static ObjectMapper getStrictJsonObjectMapper() {
+        return STRICT_JSON_OBJECT_MAPPER;
+    }
+
+    /**
+     * Get an ObjectMapper with case-insensitive property matching.
+     */
+    public static ObjectMapper getCaseInsensitiveJsonObjectMapper() {
+        return CASE_INSENSITIVE_JSON_OBJECT_MAPPER;
+    }
+
+    /**
+     * Get an ObjectMapper that sorts properties alphabetically and map entries by keys.
+     */
+    public static ObjectMapper getSortedJsonObjectMapper() {
+        return SORTED_JSON_OBJECT_MAPPER;
+    }
+
     private SerializerFactory() {
     }
 }