Used Optional to clean up some RFS Worker library code

Signed-off-by: Chris Helma <chelma+github@amazon.com>

RFS/src/main/java/com/rfs/cms/CmsClient.java

@@ -1,41 +1,45 @@
 package com.rfs.cms;
 
+import java.util.Optional;
+
 /*
  * Client to connect to and work with the Coordinating Metadata Store.  The CMS could be implemented by any reasonable
  * data store option (Postgres, AWS DynamoDB, Elasticsearch/Opensearch, etc).
  */
 public interface CmsClient {
     /*
-     * Creates a new entry in the CMS for the Snapshot's progress.  Returns true if we created the entry, and false if
-     * the entry already exists.
+     * Creates a new entry in the CMS for the Snapshot's progress.  Returns an Optional; if the document was created, it
+     * will be the created object and empty otherwise.
      */
-    public CmsEntry.Snapshot createSnapshotEntry(String snapshotName);
+    public Optional<CmsEntry.Snapshot> createSnapshotEntry(String snapshotName);
 
     /*
-     * Attempt to retrieve the Snapshot entry from the CMS, if it exists; null if it doesn't currently exist
+     * Attempt to retrieve the Snapshot entry from the CMS.  Returns an Optional; if the document exists, it will be the
+     * retrieved entry and empty otherwise.
      */
-    public CmsEntry.Snapshot getSnapshotEntry(String snapshotName);
+    public Optional<CmsEntry.Snapshot> getSnapshotEntry(String snapshotName);
 
     /*
-     * Updates the status of the Snapshot entry in the CMS.  Returns true if the update was successful, and false if
-     * something else updated it before we could
+     * Updates the Snapshot entry in the CMS.  Returns an Optional; if the document was updated, it will be
+     * the updated entry and empty otherwise.
      */
-    public CmsEntry.Snapshot updateSnapshotEntry(String snapshotName, CmsEntry.SnapshotStatus status);
+    public Optional<CmsEntry.Snapshot> updateSnapshotEntry(String snapshotName, CmsEntry.SnapshotStatus status);
 
     /*
-     * Creates a new entry in the CMS for the Metadata Migration's progress.  Returns the created entry if we created it,
-     * and null if the entry already exists.
+     * Creates a new entry in the CMS for the Metadata Migration's progress.  Returns an Optional; if the document was
+     * created, it will be the created entry and empty otherwise.
      */
-    public CmsEntry.Metadata createMetadataEntry();
+    public Optional<CmsEntry.Metadata> createMetadataEntry();
 
     /*
-     * Attempt to retrieve the Metadata Migration entry from the CMS, if it exists; null if it doesn't currently exist
+     * Attempt to retrieve the Metadata Migration entry from the CMS, if it exists.  Returns an Optional; if the document
+     * exists, it will be the retrieved entry and empty otherwise.
      */
-    public CmsEntry.Metadata getMetadataEntry();
+    public Optional<CmsEntry.Metadata> getMetadataEntry();
 
     /*
-     * Updates all fields of the Metadata Migration entry in the CMS.  Returns the updated entry if successful, and
-     * null if something else updated it before we could
+     * Updates the Metadata Migration entry in the CMS.  Returns an Optional; if the document was updated,
+     * it will be the updated entry and empty otherwise.
      */
-    public CmsEntry.Metadata updateMetadataEntry(CmsEntry.MetadataStatus status, String leaseExpiry, Integer numAttempts);
+    public Optional<CmsEntry.Metadata> updateMetadataEntry(CmsEntry.MetadataStatus status, String leaseExpiry, Integer numAttempts);
 }

RFS/src/main/java/com/rfs/cms/OpenSearchCmsClient.java

@@ -1,9 +1,9 @@
 package com.rfs.cms;
 
-import java.net.HttpURLConnection;
+import java.util.Optional;
 
+import com.fasterxml.jackson.databind.node.ObjectNode;
 import com.rfs.common.OpenSearchClient;
-import com.rfs.common.RestClient;
 
 public class OpenSearchCmsClient implements CmsClient {
     public static final String CMS_INDEX_NAME = "cms-reindex-from-snapshot";
@@ -17,73 +17,71 @@ public OpenSearchCmsClient(OpenSearchClient client) {
     }
 
     @Override
-    public CmsEntry.Snapshot createSnapshotEntry(String snapshotName) {
+    public Optional<CmsEntry.Snapshot> createSnapshotEntry(String snapshotName) {
         OpenSearchCmsEntry.Snapshot newEntry = OpenSearchCmsEntry.Snapshot.getInitial(snapshotName);
-        boolean createdEntry = client.createDocument(CMS_INDEX_NAME, CMS_SNAPSHOT_DOC_ID, newEntry.toJson());
-        if (createdEntry) {
-            return newEntry;
+        Optional<ObjectNode> createdEntry = client.createDocument(CMS_INDEX_NAME, CMS_SNAPSHOT_DOC_ID, newEntry.toJson());
+
+        if (createdEntry.isPresent()) {
+            return Optional.of(OpenSearchCmsEntry.Snapshot.fromJson(createdEntry.get()));
         } else {
-            return null;            
+            return Optional.empty();
         }
     }
 
     @Override
-    public CmsEntry.Snapshot getSnapshotEntry(String snapshotName) {
-        RestClient.Response response = client.getDocument(CMS_INDEX_NAME, CMS_SNAPSHOT_DOC_ID);
-
-        if (response.code == HttpURLConnection.HTTP_NOT_FOUND) {
-            return null;
+    public Optional<CmsEntry.Snapshot> getSnapshotEntry(String snapshotName) {
+        Optional<ObjectNode> document = client.getDocument(CMS_INDEX_NAME, CMS_SNAPSHOT_DOC_ID);
+        if (document.isEmpty()) {
+            return Optional.empty();
         }
-        return OpenSearchCmsEntry.Snapshot.fromJsonString(response.body);
+
+        ObjectNode sourceNode = (ObjectNode) document.get().get("_source");
+        return Optional.of(OpenSearchCmsEntry.Snapshot.fromJson(sourceNode));
     }
 
     @Override
-    public CmsEntry.Snapshot updateSnapshotEntry(String snapshotName, CmsEntry.SnapshotStatus status) {
+    public Optional<CmsEntry.Snapshot> updateSnapshotEntry(String snapshotName, CmsEntry.SnapshotStatus status) {
         OpenSearchCmsEntry.Snapshot entry = new OpenSearchCmsEntry.Snapshot(snapshotName, status);
-        boolean updatedEntry = client.updateDocument(CMS_INDEX_NAME, CMS_SNAPSHOT_DOC_ID, entry.toJson());
-        if (updatedEntry) {
-            return entry;
-        } else {
-            return null;            
+        Optional<ObjectNode> updatedEntry = client.updateDocument(CMS_INDEX_NAME, CMS_SNAPSHOT_DOC_ID, entry.toJson());
+        if (updatedEntry.isEmpty()) {
+            return Optional.empty();
         }
+        return Optional.of(OpenSearchCmsEntry.Snapshot.fromJson(updatedEntry.get()));
     }
 
     @Override
-    public OpenSearchCmsEntry.Metadata createMetadataEntry() {
+    public Optional<CmsEntry.Metadata> createMetadataEntry() {
         OpenSearchCmsEntry.Metadata entry = OpenSearchCmsEntry.Metadata.getInitial();
+        Optional<ObjectNode> createdEntry = client.createDocument(CMS_INDEX_NAME, CMS_METADATA_DOC_ID, entry.toJson());
 
-        boolean docCreated = client.createDocument(CMS_INDEX_NAME, CMS_METADATA_DOC_ID, entry.toJson());
-
-        if (docCreated) {
-            return entry;
-        } else {
-            return null;
+        if (createdEntry.isEmpty()) {
+            return Optional.empty();
         }
+        return Optional.of(OpenSearchCmsEntry.Metadata.fromJson(createdEntry.get()));
 
     }
 
     @Override
-    public CmsEntry.Metadata getMetadataEntry() {
-        RestClient.Response response = client.getDocument(CMS_INDEX_NAME, CMS_METADATA_DOC_ID);
+    public Optional<CmsEntry.Metadata> getMetadataEntry() {
+        Optional<ObjectNode> document = client.getDocument(CMS_INDEX_NAME, CMS_METADATA_DOC_ID);
 
-        if (response.code == HttpURLConnection.HTTP_NOT_FOUND) {
-            return null;
+        if (document.isEmpty()) {
+            return Optional.empty();
         }
-        return OpenSearchCmsEntry.Metadata.fromJsonString(response.body);
+
+        ObjectNode sourceNode = (ObjectNode) document.get().get("_source");
+        return Optional.of(OpenSearchCmsEntry.Metadata.fromJson(sourceNode));
     }
 
     @Override
-    public CmsEntry.Metadata updateMetadataEntry(CmsEntry.MetadataStatus status, String leaseExpiry, Integer numAttempts) {
+    public Optional<CmsEntry.Metadata> updateMetadataEntry(CmsEntry.MetadataStatus status, String leaseExpiry, Integer numAttempts) {
         OpenSearchCmsEntry.Metadata metadata = new OpenSearchCmsEntry.Metadata(status, leaseExpiry, numAttempts);
+        Optional<ObjectNode> updatedEntry = client.updateDocument(CMS_INDEX_NAME, CMS_METADATA_DOC_ID, metadata.toJson());
 
-        boolean updatedDoc = client.updateDocument(CMS_INDEX_NAME, CMS_METADATA_DOC_ID, metadata.toJson());
-
-        if (updatedDoc) {
-            return metadata;
-        } else {
-            return null;
+        if (updatedEntry.isEmpty()) {
+            return Optional.empty();
         }
-
+        return Optional.of(OpenSearchCmsEntry.Metadata.fromJson(updatedEntry.get()));
     }
 
 }

RFS/src/main/java/com/rfs/cms/OpenSearchCmsEntry.java

@@ -17,17 +17,14 @@ public static Snapshot getInitial(String name) {
             return new Snapshot(name, CmsEntry.SnapshotStatus.NOT_STARTED);
         }
 
-        public static Snapshot fromJsonString(String json) {
+        public static Snapshot fromJson(ObjectNode node) {
             try {
-                ObjectNode node = objectMapper.readValue(json, ObjectNode.class);
-                ObjectNode sourceNode = (ObjectNode) node.get("_source");
-
                 return new Snapshot(
-                    sourceNode.get(FIELD_STATUS).asText(),
-                    CmsEntry.SnapshotStatus.valueOf(sourceNode.get(FIELD_STATUS).asText())
+                    node.get(FIELD_STATUS).asText(),
+                    CmsEntry.SnapshotStatus.valueOf(node.get(FIELD_STATUS).asText())
                 );
             } catch (Exception e) {
-                throw new CantParseCmsEntryFromJson(Snapshot.class, json, e);
+                throw new CantParseCmsEntryFromJson(Snapshot.class, node.toString(), e);
             }
         }
 
@@ -63,18 +60,15 @@ public static Metadata getInitial() {
             );
         }
 
-        public static Metadata fromJsonString(String json) {
+        public static Metadata fromJson(ObjectNode node) {
             try {
-                ObjectNode node = objectMapper.readValue(json, ObjectNode.class);
-                ObjectNode sourceNode = (ObjectNode) node.get("_source");
-
                 return new Metadata(
-                    CmsEntry.MetadataStatus.valueOf(sourceNode.get(FIELD_STATUS).asText()),
-                    sourceNode.get(FIELD_LEASE_EXPIRY).asText(),
-                    sourceNode.get(FIELD_NUM_ATTEMPTS).asInt()
+                    CmsEntry.MetadataStatus.valueOf(node.get(FIELD_STATUS).asText()),
+                    node.get(FIELD_LEASE_EXPIRY).asText(),
+                    node.get(FIELD_NUM_ATTEMPTS).asInt()
                 );
             } catch (Exception e) {
-                throw new CantParseCmsEntryFromJson(Metadata.class, json, e);
+                throw new CantParseCmsEntryFromJson(Metadata.class, node.toString(), e);
             }
         }