[fix] when updating document, avoid NullPointerException when no time field or no document

duniter4j-es-core/src/main/java/org/duniter/elasticsearch/client/Duniter4jClient.java

@@ -62,6 +62,8 @@ public interface Duniter4jClient extends Bean, Client {
 
     Map<String, Object> getMandatoryFieldsById(String index, String type, String docId, String... fieldNames);
 
+    <T> T getMandatoryTypedFieldById(String index, String type, String docId, String fieldName);
+
     String indexDocumentFromJson(String index, String type, String json);
 
     void updateDocumentFromJson(String index, String type, String id, String json);

duniter4j-es-core/src/main/java/org/duniter/elasticsearch/client/Duniter4jClientImpl.java

@@ -325,6 +325,15 @@ public class Duniter4jClientImpl implements Duniter4jClient {
         return (T)getFieldById(index, type, docId, fieldName);
     }
 
+    @Override
+    public <T> T getMandatoryTypedFieldById(String index, String type, String docId, String fieldName) {
+        Object result = getFieldById(index, type, docId, fieldName);
+        if (result == null) {
+            throw new NotFoundException(String.format("Document [%s/%s/%s] missing value for mandatory field [%s].", index, type, docId, fieldName));
+        }
+        return (T)result;
+    }
+
     /**
      * Retrieve a document by id (safe mode)
      * @param docId

duniter4j-es-core/src/main/java/org/duniter/elasticsearch/rest/AbstractRestPostUpdateAction.java

@@ -50,7 +50,7 @@ public abstract class AbstractRestPostUpdateAction extends BaseRestHandler {
                                         String typeName,
                                         JsonUpdater updater) {
         super(settings, controller, client);
-        log = Loggers.getLogger("duniter.rest" + indexName, settings, String.format("[%s]", indexName));
+        log = Loggers.getLogger("duniter.rest." + indexName, settings, String.format("[%s]", indexName));
         controller.registerHandler(POST,
                 String.format("/%s/%s/{id}/_update", indexName, typeName),
                 this);

duniter4j-es-core/src/main/java/org/duniter/elasticsearch/service/AbstractService.java

@@ -170,7 +170,7 @@ public abstract class AbstractService implements Bean {
     protected void verifyTimeForUpdate(String index, String type, String id, JsonNode actualObj, boolean allowOldDocuments, String timeFieldName) {
         // Check time has been increase - fix #27
         int actualTime = getMandatoryField(actualObj, timeFieldName).asInt();
-        int existingTime = client.getTypedFieldById(index, type, id, timeFieldName);
+        int existingTime = client.getMandatoryTypedFieldById(index, type, id, timeFieldName);
         if (actualTime <= existingTime) {
             throw new InvalidTimeException(String.format("Invalid '%s' value: can not be less or equal to the previous value.", timeFieldName, timeFieldName));
         }