Github user pvillard31 commented on a diff in the pull request:
https://github.com/apache/nifi/pull/2558#discussion_r195999042
--- Diff:
nifi-nar-bundles/nifi-standard-services/nifi-lookup-services-bundle/nifi-lookup-services/src/main/java/org/apache/nifi/lookup/DistributedMapCacheLookupService.java
---
@@ -0,0 +1,155 @@
+/*
+ * 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.lookup;
+
+import java.io.IOException;
+import java.io.OutputStream;
+import java.nio.charset.Charset;
+import java.nio.charset.StandardCharsets;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+import java.util.Map;
+import java.util.Optional;
+import java.util.Set;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
+
+import org.apache.nifi.annotation.documentation.CapabilityDescription;
+import org.apache.nifi.annotation.documentation.Tags;
+import org.apache.nifi.annotation.lifecycle.OnEnabled;
+import org.apache.nifi.components.PropertyDescriptor;
+import org.apache.nifi.components.Validator;
+import org.apache.nifi.controller.AbstractControllerService;
+import org.apache.nifi.controller.ConfigurationContext;
+import org.apache.nifi.distributed.cache.client.Deserializer;
+import org.apache.nifi.distributed.cache.client.DistributedMapCacheClient;
+import org.apache.nifi.distributed.cache.client.Serializer;
+import
org.apache.nifi.distributed.cache.client.exception.DeserializationException;
+import
org.apache.nifi.distributed.cache.client.exception.SerializationException;
+import org.apache.nifi.expression.ExpressionLanguageScope;
+
+@Tags({"lookup", "enrich", "key", "value", "map", "cache", "distributed"})
+@CapabilityDescription("Allows to choose a distributed map cache client to
retrieve the value associated to a key. "
+ + "The coordinates that are passed to the lookup must contain the key
'key'.")
+public class DistributedMapCacheLookupService extends
AbstractControllerService implements StringLookupService {
+
+ private static final List<Charset> STANDARD_CHARSETS = Arrays.asList(
+ StandardCharsets.UTF_8,
+ StandardCharsets.US_ASCII,
+ StandardCharsets.ISO_8859_1,
+ StandardCharsets.UTF_16,
+ StandardCharsets.UTF_16LE,
+ StandardCharsets.UTF_16BE);
+
+ private static final String KEY = "key";
+ private static final Set<String> REQUIRED_KEYS =
Stream.of(KEY).collect(Collectors.toSet());
+
+ private volatile DistributedMapCacheClient cache;
+ private volatile static Charset charset;
+ private final Serializer<String> keySerializer = new
StringSerializer();
+ private final Deserializer<String> valueDeserializer = new
StringDeserializer();
+
+ public static final PropertyDescriptor PROP_DISTRIBUTED_CACHE_SERVICE
= new PropertyDescriptor.Builder()
+ .name("distributed-map-cache-service")
+ .displayName("Distributed Cache Service")
+ .description("The Controller Service that is used to get the
cached values.")
+ .required(true)
+ .identifiesControllerService(DistributedMapCacheClient.class)
+ .build();
+
+ public static final PropertyDescriptor CHARACTER_ENCODING = new
PropertyDescriptor.Builder()
+ .name("character-encoding")
+ .displayName("Character Encoding")
+ .description("Specifies a character encoding to use.")
+ .required(true)
+ .allowableValues(getStandardCharsetNames())
+ .defaultValue(StandardCharsets.UTF_8.displayName())
+ .build();
+
+ private static Set<String> getStandardCharsetNames() {
+ return STANDARD_CHARSETS.stream().map(c ->
c.displayName()).collect(Collectors.toSet());
+ }
+
+ @Override
+ protected PropertyDescriptor
getSupportedDynamicPropertyDescriptor(final String propertyDescriptorName) {
+ return new PropertyDescriptor.Builder()
+ .name(propertyDescriptorName)
+ .required(false)
+ .dynamic(true)
+ .addValidator(Validator.VALID)
+
.expressionLanguageSupported(ExpressionLanguageScope.FLOWFILE_ATTRIBUTES)
+ .build();
+ }
+
+ @OnEnabled
+ public void cacheConfiguredValues(final ConfigurationContext context) {
--- End diff --
True - done!
---
