Github user mattyb149 commented on a diff in the pull request:
https://github.com/apache/nifi/pull/2956#discussion_r222756058
--- Diff:
nifi-nar-bundles/nifi-neo4j-bundle/nifi-neo4j-processors/src/main/java/org/apache/nifi/processors/neo4j/AbstractNeo4JCypherExecutor.java
---
@@ -0,0 +1,279 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.nifi.processors.neo4j;
+
+import java.io.File;
+import java.util.concurrent.TimeUnit;
+
+import org.apache.commons.lang3.StringUtils;
+import org.apache.nifi.annotation.lifecycle.OnScheduled;
+import org.apache.nifi.annotation.lifecycle.OnStopped;
+import org.apache.nifi.components.AllowableValue;
+import org.apache.nifi.components.PropertyDescriptor;
+import org.apache.nifi.components.PropertyValue;
+import org.apache.nifi.expression.ExpressionLanguageScope;
+import org.apache.nifi.processor.AbstractProcessor;
+import org.apache.nifi.processor.ProcessContext;
+import org.apache.nifi.processor.Relationship;
+import org.apache.nifi.processor.util.StandardValidators;
+import org.neo4j.driver.v1.AuthTokens;
+import org.neo4j.driver.v1.Config;
+import org.neo4j.driver.v1.Config.ConfigBuilder;
+import org.neo4j.driver.v1.Config.LoadBalancingStrategy;
+import org.neo4j.driver.v1.Config.TrustStrategy;
+import org.neo4j.driver.v1.Driver;
+import org.neo4j.driver.v1.GraphDatabase;
+
+/**
+ * Abstract base class for Neo4JCypherExecutor processors
+ */
+abstract class AbstractNeo4JCypherExecutor extends AbstractProcessor {
+
+ protected static final PropertyDescriptor QUERY = new
PropertyDescriptor.Builder()
+ .name("neo4J-query")
+ .displayName("Neo4J Query")
+ .description("Specifies the Neo4j Query.")
+ .required(true)
+
.expressionLanguageSupported(ExpressionLanguageScope.FLOWFILE_ATTRIBUTES)
+ .addValidator(StandardValidators.NON_BLANK_VALIDATOR)
+ .build();
+
+ public static final PropertyDescriptor CONNECTION_URL = new
PropertyDescriptor.Builder()
+ .name("neo4j-connection-url")
+ .displayName("Neo4j Connection URL")
+ .description("Neo4J endpoing to connect to.")
+ .required(true)
+ .defaultValue("bolt://localhost:7687")
+
.expressionLanguageSupported(ExpressionLanguageScope.VARIABLE_REGISTRY)
+ .addValidator(StandardValidators.NON_EMPTY_VALIDATOR)
+ .build();
+
+ public static final PropertyDescriptor USERNAME = new
PropertyDescriptor.Builder()
+ .name("neo4j-username")
+ .displayName("Username")
+ .description("Username for accessing Neo4J")
+ .required(true)
+
.expressionLanguageSupported(ExpressionLanguageScope.VARIABLE_REGISTRY)
+ .addValidator(StandardValidators.NON_BLANK_VALIDATOR)
+ .build();
+
+ public static final PropertyDescriptor PASSWORD = new
PropertyDescriptor.Builder()
+ .name("neo4j-password")
+ .displayName("Password")
+ .description("Password for Neo4J user")
+ .required(true)
+ .sensitive(true)
+
.expressionLanguageSupported(ExpressionLanguageScope.VARIABLE_REGISTRY)
+ .addValidator(StandardValidators.NON_BLANK_VALIDATOR)
+ .build();
+
+ public static AllowableValue LOAD_BALANCING_STRATEGY_ROUND_ROBIN = new
AllowableValue(LoadBalancingStrategy.ROUND_ROBIN.name(), "Round Robin", "Round
Robin Strategy");
+
+ public static AllowableValue LOAD_BALANCING_STRATEGY_LEAST_CONNECTED =
new AllowableValue(LoadBalancingStrategy.LEAST_CONNECTED.name(), "Least
Connected", "Least Connected Strategy");
+
+ protected static final PropertyDescriptor LOAD_BALANCING_STRATEGY =
new PropertyDescriptor.Builder()
+ .name("neo4j-load-balancing-strategy")
+ .displayName("Load Balancing Strategy")
+ .description("Load Balancing Strategy (Round Robin or Least
Connected)")
+ .required(false)
+ .defaultValue(LOAD_BALANCING_STRATEGY_ROUND_ROBIN.getValue())
+ .allowableValues(LOAD_BALANCING_STRATEGY_ROUND_ROBIN,
LOAD_BALANCING_STRATEGY_LEAST_CONNECTED)
+ .build();
+
+ public static final PropertyDescriptor CONNECTION_TIMEOUT = new
PropertyDescriptor.Builder()
+ .name("neo4j-max-connection-time-out")
+ .displayName("Neo4J Max Connection Time Out (seconds)")
+ .description("The maximum time for establishing connection to
the Neo4j")
+ .defaultValue("5 seconds")
+ .required(true)
+ .addValidator(StandardValidators.TIME_PERIOD_VALIDATOR)
+ .sensitive(false)
+ .build();
+
+ public static final PropertyDescriptor MAX_CONNECTION_POOL_SIZE = new
PropertyDescriptor.Builder()
--- End diff --
I agree with Mike here, a controller service will be much more flexible and
future-proof. For example, I want to try a PutRecordWithCypher processor where
you can supply a Cypher command and then call it for each record (or send all
into an UNWIND-wrapped Cypher query). In this case we'd want to share the
connection pool amongst the processor instances.
In addition, providing a Controller Service interface should allow you to
decouple the processor from the driver. Then we don't need "Neo4J" in the
processor name or the processor dependencies, and you could use the same
processor with [other projects](https://www.opencypher.org/projects) by
implementing different versions of the controller service.
---
