NIFI-3679: This closes #1655. Added Avro Content Viewer

Signed-off-by: joewitt <joewitt@apache.org>

nifi-nar-bundles/nifi-standard-bundle/nifi-standard-content-viewer/pom.xml

@@ -1,18 +1,15 @@
-<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-    <!--
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
-      Licensed to the Apache Software Foundation (ASF) under one or more
+    <!-- Licensed to the Apache Software Foundation (ASF) under one or more 
-      contributor license agreements.  See the NOTICE file distributed with
+        contributor license agreements. See the NOTICE file distributed with this 
-      this work for additional information regarding copyright ownership.
+        work for additional information regarding copyright ownership. The ASF licenses 
-      The ASF licenses this file to You under the Apache License, Version 2.0
+        this file to You under the Apache License, Version 2.0 (the "License"); you 
-      (the "License"); you may not use this file except in compliance with
+        may not use this file except in compliance with the License. You may obtain 
-      the License.  You may obtain a copy of the License at
+        a copy of the License at http://www.apache.org/licenses/LICENSE-2.0 Unless 
-          http://www.apache.org/licenses/LICENSE-2.0
+        required by applicable law or agreed to in writing, software distributed 
-      Unless required by applicable law or agreed to in writing, software
+        under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES 
-      distributed under the License is distributed on an "AS IS" BASIS,
+        OR CONDITIONS OF ANY KIND, either express or implied. See the License for 
-      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+        the specific language governing permissions and limitations under the License. -->
-      See the License for the specific language governing permissions and
-      limitations under the License.
-    -->
     <modelVersion>4.0.0</modelVersion>
     <parent>
         <groupId>org.apache.nifi</groupId>
@@ -63,5 +60,15 @@
             <groupId>javax.servlet</groupId>
             <artifactId>javax.servlet-api</artifactId>
         </dependency>
+        <dependency>
+            <groupId>org.apache.avro</groupId>
+            <artifactId>avro</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.xerial.snappy</groupId>
+            <artifactId>snappy-java</artifactId>
+            <version>1.1.2</version>
+        </dependency>
+
     </dependencies>
 </project>

nifi-nar-bundles/nifi-standard-bundle/nifi-standard-content-viewer/src/main/java/org/apache/nifi/web/StandardContentViewerController.java

@@ -17,6 +17,11 @@
 package org.apache.nifi.web;
 
 import com.fasterxml.jackson.databind.ObjectMapper;
+
+import org.apache.avro.file.DataFileStream;
+import org.apache.avro.generic.GenericData;
+import org.apache.avro.generic.GenericDatumReader;
+import org.apache.avro.io.DatumReader;
 import org.apache.nifi.web.ViewableContent.DisplayMode;
 
 import javax.servlet.ServletException;
@@ -33,9 +38,23 @@ import javax.xml.transform.stream.StreamSource;
 import java.io.IOException;
 import java.io.PrintWriter;
 import java.io.StringWriter;
+import java.util.HashSet;
+import java.util.Set;
 
 public class StandardContentViewerController extends HttpServlet {
 
+    private static final Set<String> supportedMimeTypes = new HashSet<>();
+
+    static {
+        supportedMimeTypes.add("application/json");
+        supportedMimeTypes.add("application/xml");
+        supportedMimeTypes.add("text/plain");
+        supportedMimeTypes.add("text/csv");
+        supportedMimeTypes.add("application/avro-binary");
+        supportedMimeTypes.add("avro/binary");
+        supportedMimeTypes.add("application/avro+binary");
+    }
+
     /**
      *
      * @param request servlet request
@@ -48,8 +67,8 @@ public class StandardContentViewerController extends HttpServlet {
         final ViewableContent content = (ViewableContent) request.getAttribute(ViewableContent.CONTENT_REQUEST_ATTRIBUTE);
 
         // handle json/xml specifically, treat others as plain text
-        final String contentType = content.getContentType();
+        String contentType = content.getContentType();
-        if ("application/json".equals(contentType) || "application/xml".equals(contentType) || "text/plain".equals(contentType) || "text/csv".equals(contentType)) {
+        if (supportedMimeTypes.contains(contentType)) {
             final String formatted;
 
             // leave the content alone if specified
@@ -81,6 +100,34 @@ public class StandardContentViewerController extends HttpServlet {
 
                     // get the transformed xml
                     formatted = writer.toString();
+                } else if ("application/avro-binary".equals(contentType) || "avro/binary".equals(contentType) || "application/avro+binary".equals(contentType)) {
+                    final StringBuilder sb = new StringBuilder();
+                    sb.append("[");
+                    final DatumReader<GenericData.Record> datumReader = new GenericDatumReader<>();
+                    try (final DataFileStream<GenericData.Record> dataFileReader = new DataFileStream<>(content.getContentStream(), datumReader)) {
+                        while (dataFileReader.hasNext()) {
+                            final GenericData.Record record = dataFileReader.next();
+                            final String formattedRecord = record.toString();
+                            sb.append(formattedRecord);
+                            sb.append(",");
+                            // Do not format more than 10 MB of content.
+                            if (sb.length() > 1024 * 1024 * 2) {
+                                break;
+                            }
+                        }
+                    }
+
+                    if (sb.length() > 1) {
+                        sb.deleteCharAt(sb.length() - 1);
+                    }
+                    sb.append("]");
+                    final String json = sb.toString();
+
+                    final ObjectMapper mapper = new ObjectMapper();
+                    final Object objectJson = mapper.readValue(json, Object.class);
+                    formatted = mapper.writerWithDefaultPrettyPrinter().writeValueAsString(objectJson);
+
+                    contentType = "application/json";
                 } else {
                     // leave plain text alone when formatting
                     formatted = content.getContent();

nifi-nar-bundles/nifi-standard-bundle/nifi-standard-content-viewer/src/main/resources/META-INF/NOTICE

@@ -17,3 +17,21 @@ The following binary components are provided under the Apache Software License v
 
       This product includes software from the Spring Framework,
       under the Apache License 2.0 (see: StringUtils.containsWhitespace())
+
+  (ASLv2) Apache Avro
+    The following NOTICE information applies:
+      Apache Avro
+      Copyright 2009-2013 The Apache Software Foundation
+
+  (ASLv2) Snappy Java
+    The following NOTICE information applies:
+      This product includes software developed by Google
+       Snappy: http://code.google.com/p/snappy/ (New BSD License)
+
+      This product includes software developed by Apache
+       PureJavaCrc32C from apache-hadoop-common http://hadoop.apache.org/
+       (Apache 2.0 license)
+
+      This library containd statically linked libstdc++. This inclusion is allowed by
+      "GCC RUntime Library Exception"
+      http://gcc.gnu.org/onlinedocs/libstdc++/manual/license.html

nifi-nar-bundles/nifi-standard-bundle/nifi-standard-content-viewer/src/main/webapp/META-INF/nifi-content-viewer

@@ -15,4 +15,7 @@
 application/xml
 application/json
 text/plain
-text/csv
+text/csv
+avro/binary
+application/avro-binary
+application/avro+binary