Github user JPercivall commented on a diff in the pull request:
https://github.com/apache/nifi/pull/576#discussion_r69324539
--- Diff:
nifi-nar-bundles/nifi-elasticsearch-bundle/nifi-elasticsearch-processors/src/main/java/org/apache/nifi/processors/elasticsearch/FetchElasticsearchHttp.java
---
@@ -0,0 +1,293 @@
+/*
+ * 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.elasticsearch;
+
+import com.squareup.okhttp.HttpUrl;
+import com.squareup.okhttp.OkHttpClient;
+import com.squareup.okhttp.Response;
+import com.squareup.okhttp.ResponseBody;
+import org.apache.commons.lang3.StringUtils;
+import org.apache.nifi.annotation.behavior.EventDriven;
+import org.apache.nifi.annotation.behavior.InputRequirement;
+import org.apache.nifi.annotation.behavior.SupportsBatching;
+import org.apache.nifi.annotation.behavior.WritesAttribute;
+import org.apache.nifi.annotation.behavior.WritesAttributes;
+import org.apache.nifi.annotation.documentation.CapabilityDescription;
+import org.apache.nifi.annotation.documentation.Tags;
+import org.apache.nifi.annotation.lifecycle.OnScheduled;
+import org.apache.nifi.components.PropertyDescriptor;
+import org.apache.nifi.flowfile.FlowFile;
+import org.apache.nifi.logging.ComponentLog;
+import org.apache.nifi.processor.ProcessContext;
+import org.apache.nifi.processor.ProcessSession;
+import org.apache.nifi.processor.Relationship;
+import org.apache.nifi.processor.exception.ProcessException;
+import org.apache.nifi.processor.util.StandardValidators;
+import org.apache.nifi.stream.io.ByteArrayInputStream;
+import org.codehaus.jackson.JsonNode;
+
+import java.io.IOException;
+import java.net.MalformedURLException;
+import java.net.URL;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Set;
+import java.util.concurrent.TimeUnit;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
+
+
+@InputRequirement(InputRequirement.Requirement.INPUT_ALLOWED)
+@EventDriven
+@SupportsBatching
+@Tags({"elasticsearch", "fetch", "read", "get", "http"})
+@CapabilityDescription("Retrieves a document from Elasticsearch using the
specified connection properties and the "
+ + "identifier of the document to retrieve.")
+@WritesAttributes({
+ @WritesAttribute(attribute = "filename", description = "The
filename attributes is set to the document identifier"),
+ @WritesAttribute(attribute = "es.index", description = "The
Elasticsearch index containing the document"),
+ @WritesAttribute(attribute = "es.type", description = "The
Elasticsearch document type")
+})
+public class FetchElasticsearchHttp extends
AbstractElasticsearchHttpProcessor {
+
+ private static final String FIELD_INCLUDE_QUERY_PARAM =
"_source_include";
+
+ public static final Relationship REL_SUCCESS = new
Relationship.Builder().name("success")
+ .description("All FlowFiles that are read from Elasticsearch
are routed to this relationship").build();
+
+ public static final Relationship REL_FAILURE = new
Relationship.Builder().name("failure")
+ .description("All FlowFiles that cannot be read from
Elasticsearch are routed to this relationship").build();
+
+ public static final Relationship REL_RETRY = new
Relationship.Builder().name("retry")
+ .description("A FlowFile is routed to this relationship if the
document cannot be fetched but attempting the operation again may succeed")
+ .build();
+
+ public static final Relationship REL_NOT_FOUND = new
Relationship.Builder().name("not found")
+ .description("A FlowFile is routed to this relationship if the
specified document does not exist in the Elasticsearch cluster")
+ .build();
+
+ public static final PropertyDescriptor DOC_ID = new
PropertyDescriptor.Builder()
+ .name("Document Identifier")
+ .description("The identifier for the document to be fetched")
+ .required(true)
+ .expressionLanguageSupported(true)
+ .addValidator(StandardValidators.NON_EMPTY_VALIDATOR)
+ .build();
+
+ public static final PropertyDescriptor INDEX = new
PropertyDescriptor.Builder()
+ .name("Index")
+ .description("The name of the index to read from")
+ .required(true)
+ .expressionLanguageSupported(true)
+ .addValidator(StandardValidators.NON_EMPTY_VALIDATOR)
+ .build();
+
+ public static final PropertyDescriptor TYPE = new
PropertyDescriptor.Builder()
+ .name("Type")
+ .description("The (optional) type of this document, used by
Elasticsearch for indexing and searching.")
+ .required(false)
+ .expressionLanguageSupported(true)
+ .addValidator(StandardValidators.NON_EMPTY_VALIDATOR)
+ .build();
+
+ public static final PropertyDescriptor FIELDS = new
PropertyDescriptor.Builder()
+ .name("Fields")
+ .description("A comma-separated list of fields to retrieve
from the document. If the Fields property is left blank, "
+ + "then the entire document's source will be
retrieved.")
+ .required(false)
+ .expressionLanguageSupported(true)
+ .addValidator(StandardValidators.NON_EMPTY_VALIDATOR)
+ .build();
+
+
+ @Override
+ public Set<Relationship> getRelationships() {
+ final Set<Relationship> relationships = new HashSet<>();
+ relationships.add(REL_SUCCESS);
+ relationships.add(REL_FAILURE);
+ relationships.add(REL_RETRY);
+ relationships.add(REL_NOT_FOUND);
+ return Collections.unmodifiableSet(relationships);
+ }
+
+ @Override
+ public final List<PropertyDescriptor>
getSupportedPropertyDescriptors() {
+ final List<PropertyDescriptor> descriptors = new ArrayList<>();
+ descriptors.add(ES_URL);
+ descriptors.add(PROP_SSL_CONTEXT_SERVICE);
+ descriptors.add(CONNECT_TIMEOUT);
+ descriptors.add(RESPONSE_TIMEOUT);
+ descriptors.add(DOC_ID);
+ descriptors.add(INDEX);
+ descriptors.add(TYPE);
+ descriptors.add(FIELDS);
+
+ return Collections.unmodifiableList(descriptors);
+ }
+
+
+ @OnScheduled
+ public void setup(ProcessContext context) {
+ super.setup(context);
+ }
+
+ @Override
+ public void onTrigger(final ProcessContext context, final
ProcessSession session) throws ProcessException {
+
+ FlowFile flowFile = null;
+ if (context.hasIncomingConnection()) {
+ flowFile = session.get();
+
+ // If we have no FlowFile, and all incoming connections are
self-loops then we can continue on.
+ // However, if we have no FlowFile and we have connections
coming from other Processors, then
+ // we know that we should run only if we have a FlowFile.
+ if (flowFile == null && context.hasNonLoopConnection()) {
+ return;
+ }
+ }
+
+ OkHttpClient okHttpClient = getClient();
+
+ if (flowFile == null) {
+ flowFile = session.create();
+ }
+
+ final String index =
context.getProperty(INDEX).evaluateAttributeExpressions(flowFile).getValue();
+ final String docId =
context.getProperty(DOC_ID).evaluateAttributeExpressions(flowFile).getValue();
+ final String docType =
context.getProperty(TYPE).evaluateAttributeExpressions(flowFile).getValue();
+ final String fields = context.getProperty(FIELDS).isSet()
+ ?
context.getProperty(FIELDS).evaluateAttributeExpressions(flowFile).getValue()
+ : null;
+
+ final ComponentLog logger = getLogger();
+
+
+ try {
+ logger.debug("Fetching {}/{}/{} from Elasticsearch", new
Object[]{index, docType, docId});
+
+ // read the url property from the context
+ final String urlstr =
StringUtils.trimToEmpty(context.getProperty(ES_URL).getValue());
+ final URL url = buildRequestURL(urlstr, docId, index, docType,
fields);
+ final long startNanos = System.nanoTime();
+
+ final Response getResponse =
sendRequestToElasticsearch(okHttpClient, url, "GET", null);
+ final int statusCode = getResponse.code();
+
+ if (isSuccess(statusCode)) {
+ ResponseBody body = getResponse.body();
+ final byte[] bodyBytes = body.bytes();
+ JsonNode responseJson = parseJsonResponse(new
ByteArrayInputStream(bodyBytes));
+ boolean found = responseJson.get("found").asBoolean(false);
+
+ if (found) {
+ flowFile = session.putAttribute(flowFile, "filename",
docId);
+ flowFile = session.putAttribute(flowFile, "es.index",
index);
+ flowFile = session.putAttribute(flowFile, "es.type",
docType);
--- End diff --
Doctype (as set in the property) could potentially not be set, probably
better to take it from the responseJson
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