NIFI-934:

- Added a content viewer for image files.

nifi-nar-bundles/nifi-image-bundle/nifi-image-nar/pom.xml

@@ -32,6 +32,12 @@
             <artifactId>nifi-image-processors</artifactId>
             <version>0.3.1-SNAPSHOT</version>
         </dependency>
+        <dependency>
+            <groupId>org.apache.nifi</groupId>
+            <artifactId>nifi-image-viewer</artifactId>
+            <version>0.3.1-SNAPSHOT</version>
+            <type>war</type>
+        </dependency>
     </dependencies>
 
 </project>

nifi-nar-bundles/nifi-image-bundle/nifi-image-viewer/pom.xml

@@ -0,0 +1,48 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<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
+      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.
+    -->
+    <modelVersion>4.0.0</modelVersion>
+    <parent>
+        <groupId>org.apache.nifi</groupId>
+        <artifactId>nifi-image-bundle</artifactId>
+        <version>0.3.1-SNAPSHOT</version>
+    </parent>
+    <artifactId>nifi-image-viewer</artifactId>
+    <description>NiFi image viewer</description>
+    <packaging>war</packaging>
+    <dependencies>
+        <dependency>
+            <groupId>org.apache.nifi</groupId>
+            <artifactId>nifi-api</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>javax.servlet.jsp</groupId>
+            <artifactId>javax.servlet.jsp-api</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>javax.el</groupId>
+            <artifactId>javax.el-api</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>javax.servlet.jsp.jstl</groupId>
+            <artifactId>javax.servlet.jsp.jstl-api</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>javax.servlet</groupId>
+            <artifactId>javax.servlet-api</artifactId>
+        </dependency>
+    </dependencies>
+</project>

nifi-nar-bundles/nifi-image-bundle/nifi-image-viewer/src/main/java/org/apache/nifi/web/ImageViewerController.java

@@ -0,0 +1,52 @@
+/*
+ * 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.web;
+
+import java.io.IOException;
+import java.io.PrintWriter;
+
+import javax.servlet.ServletException;
+import javax.servlet.annotation.WebServlet;
+import javax.servlet.http.HttpServlet;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+
+@WebServlet(name = "ImageViewer", urlPatterns = {"/view-content"})
+public class ImageViewerController extends HttpServlet {
+
+    /**
+     * Handles generating markup for viewing an image.
+     *
+     * @param request servlet request
+     * @param response servlet response
+     * @throws ServletException if a servlet-specific error occurs
+     * @throws IOException if an I/O error occurs
+     */
+    @Override
+    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
+        final ViewableContent content = (ViewableContent) request.getAttribute(ViewableContent.CONTENT_REQUEST_ATTRIBUTE);
+
+        // handle images
+        if ("image/png".equals(content.getContentType()) || "image/jpeg".equals(content.getContentType()) || "image/gif".equals(content.getContentType())) {
+            // defer to the jsp
+            request.getRequestDispatcher("/WEB-INF/jsp/image.jsp").include(request, response);
+        } else {
+            final PrintWriter out = response.getWriter();
+            out.println("Unexpected content type: " + content.getContentType());
+        }
+    }
+}

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

@@ -0,0 +1,17 @@
+# 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.
+image/png
+image/jpeg
+image/gif

nifi-nar-bundles/nifi-image-bundle/nifi-image-viewer/src/main/webapp/WEB-INF/jsp/image.jsp

@@ -0,0 +1,39 @@
+<%--
+ 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.
+--%>
+<%@ page contentType="text/html" pageEncoding="UTF-8" session="false" %>
+<script type="text/javascript" src="../nifi/js/jquery/jquery-2.1.1.min.js"></script>
+<style>
+    #image-holder {
+        position: absolute;
+        right: 50px;
+        bottom: 50px;
+        left: 100px;
+        top: 100px;
+        border: 1px solid #aaa;
+        overflow: auto;
+        background-color: #fff;
+        padding: 4px;
+    }
+</style>
+<div id="image-holder"></div>
+<script type="text/javascript">
+    $(document).ready(function() {
+        var ref = $('#ref').text();
+        var imgElement = $('<img/>').attr('src', ref);
+        $('#image-holder').append(imgElement);
+    });
+</script>

nifi-nar-bundles/nifi-image-bundle/nifi-image-viewer/src/main/webapp/WEB-INF/web.xml

@@ -0,0 +1,29 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+  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.
+-->
+<web-app version="3.0" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd">
+    <display-name>nifi-image-viewer</display-name>
+    <servlet>
+        <servlet-name>ImageViewer</servlet-name>
+        <servlet-class>org.apache.nifi.web.ImageViewerController</servlet-class>
+    </servlet>
+    <servlet-mapping>
+        <servlet-name>ImageViewer</servlet-name>
+        <url-pattern>/view-content</url-pattern>
+    </servlet-mapping>
+    <welcome-file-list>
+        <welcome-file>view-content</welcome-file>
+    </welcome-file-list>
+</web-app>

nifi-nar-bundles/nifi-image-bundle/pom.xml

@@ -29,6 +29,7 @@
     <modules>
         <module>nifi-image-processors</module>
         <module>nifi-image-nar</module>
+        <module>nifi-image-viewer</module>
     </modules>
 
 </project>