Github user cestella commented on a diff in the pull request:
https://github.com/apache/metron/pull/1084#discussion_r201448152
--- Diff:
metron-platform/metron-common/src/main/java/org/apache/metron/common/message/metadata/EnvelopedRawMessageStrategy.java
---
@@ -0,0 +1,146 @@
+/**
+ * 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.metron.common.message.metadata;
+
+import org.apache.metron.common.Constants;
+import org.apache.metron.common.utils.JSONUtils;
+import org.json.simple.JSONObject;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.io.IOException;
+import java.lang.invoke.MethodHandles;
+import java.util.HashMap;
+import java.util.Map;
+
+/**
+ * An alternative strategy whereby
+ * <ul>
+ * <li>The raw data is presumed to be a JSON Map</li>
+ * <li>The data to be parsed is the contents of one of the fields.</li>
+ * <li>The non-data fields are considered metadata</li>
+ * </ul>
+ *
+ * Additionally, the defaults around merging and reading metadata are
adjusted to be on by default.
+ * Note, this strategy allows for parser chaining and for a fully worked
example, check the parser chaining use-case.
+ */
+public class EnvelopedRawMessageStrategy implements RawMessageStrategy {
+ private static final Logger LOG =
LoggerFactory.getLogger(MethodHandles.lookup().lookupClass());
+ /**
+ * The field from the rawMessageStrategyConfig in the SensorParserConfig
that defines the field to use to
+ * define the data to be parsed.
+ */
+ public static final String MESSAGE_FIELD_CONFIG = "messageField";
+
+ /**
+ * Retrieve the raw message by parsing the JSON Map in the kafka value
and pulling the appropriate field.
+ * Also, augment the default metadata with the non-data fields in the
JSON Map.
+ *
+ * Note: The data field in the JSON Map is not considered metadata.
+ *
+ * @param rawMetadata The metadata read from kafka Key (e.g. the topic,
index, etc.)
+ * @param rawMessage The raw message from the kafka value
+ * @param readMetadata True if we want to read read the metadata
+ * @param config The config for the RawMessageStrategy (See the
rawMessageStrategyConfig in the SensorParserConfig)
+ * @return
+ */
+ @Override
+ public RawMessage get(Map<String, Object> rawMetadata, byte[]
rawMessage, boolean readMetadata, Map<String, Object> config) {
+ String messageField = (String)config.get(MESSAGE_FIELD_CONFIG);
+ if(messageField == null) {
+ throw new IllegalStateException("You must specify a message field in
the message supplier config. " +
+ "I expected to find a \"messageField\" field in the
config.");
--- End diff --
haha
---
