Add Jython support

build.gradle

@@ -23,7 +23,7 @@ plugins {
     id 'com.github.johnrengelman.shadow' version '1.2.3'
 }
 
-version = '1.1.1'
+version = '1.1.2'
 description = "A project to create a stub/mock environment for testing ExecuteScript processors"
 group = 'mattyb149'
 status = 'RELEASE'
@@ -45,6 +45,7 @@ dependencies {
 
     // script engine(s)
     runtime 'org.codehaus.groovy:groovy-all:2.4.6'
+    runtime 'org.python:jython-standalone:2.7.0'
 }
 
 mainClassName = 'nifi.ScriptRunner'
@@ -114,5 +115,5 @@ bintray {
 }
 
 task wrapper(type: Wrapper) {
-    gradleVersion = "2.13"
+    gradleVersion = "3.5"
 }

src/main/java/nifi/script/impl/JythonScriptEngineConfigurator.java

@@ -0,0 +1,63 @@
+/*
+ * 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 nifi.script.impl;
+
+import org.apache.nifi.logging.ComponentLog;
+import nifi.script.ScriptEngineConfigurator;
+
+import javax.script.ScriptEngine;
+import javax.script.ScriptException;
+import java.net.URL;
+
+/**
+ * A helper class to configure the Jython engine with any specific requirements
+ */
+public class JythonScriptEngineConfigurator implements ScriptEngineConfigurator {
+
+    @Override
+    public String getScriptEngineName() {
+        return "python";
+    }
+
+    @Override
+    public URL[] getModuleURLsForClasspath(String[] modulePaths, ComponentLog log) {
+        // We don't need to add the module paths to the classpath, they will be added via sys.path.append
+        return new URL[0];
+    }
+
+    @Override
+    public Object init(ScriptEngine engine, String[] modulePaths) throws ScriptException {
+        return null;
+    }
+
+    @Override
+    public Object eval(ScriptEngine engine, String scriptBody, String[] modulePaths) throws ScriptException {
+        Object returnValue = null;
+        if (engine != null) {
+            // Need to import the module path inside the engine, in order to pick up
+            // other Python/Jython modules
+            engine.eval("import sys");
+            if (modulePaths != null) {
+                for (String modulePath : modulePaths) {
+                    engine.eval("sys.path.append('" + modulePath + "')");
+                }
+            }
+            returnValue = engine.eval(scriptBody);
+        }
+        return returnValue;
+    }
+}

src/main/resources/META-INF/services/javax.script.ScriptEngineFactory

@@ -0,0 +1,2 @@
+org.codehaus.groovy.jsr223.GroovyScriptEngineFactory
+org.python.jsr223.PyScriptEngineFactory

src/main/resources/META-INF/services/nifi.script.ScriptEngineConfigurator

@@ -15,3 +15,4 @@
 
 nifi.script.impl.GroovyScriptEngineConfigurator
 nifi.script.impl.JavascriptScriptEngineConfigurator
+nifi.script.impl.JythonScriptEngineConfigurator

src/test/java/nifi/ScriptRunnerTest.java

@@ -76,9 +76,15 @@ public void testOutputAllWithInputDir() throws Exception {
     }
 
     @Test
-    public void testReadWrite() throws Exception {
+    public void testReadWriteGroovy() throws Exception {
         System.setIn(new FileInputStream("src/test/resources/input_files/jolt.json"));
         ScriptRunner.main(new String[]{"-all", "src/test/resources/test_json2json.groovy"});
     }
 
+    @Test
+    public void testReadWriteJython() throws Exception {
+        System.setIn(new FileInputStream("src/test/resources/input_files/jolt.json"));
+        ScriptRunner.main(new String[]{"-all", "src/test/resources/test_json2json.py"});
+    }
+
 }

src/test/resources/test_json2json.py

@@ -0,0 +1,28 @@
+import json
+import java.io
+from org.apache.commons.io import IOUtils
+from java.nio.charset import StandardCharsets
+from org.apache.nifi.processor.io import StreamCallback
+
+class PyStreamCallback(StreamCallback):
+    def __init__(self):
+        pass
+    def process(self, inputStream, outputStream):
+        text = IOUtils.toString(inputStream, StandardCharsets.UTF_8)
+        obj = json.loads(text)
+        newObj = {
+            "Range": 5,
+            "Rating": obj['rating']['primary']['value'],
+            "SecondaryRatings": {}
+        }
+        for key, value in obj['rating'].iteritems():
+            if key != "primary":
+                newObj['SecondaryRatings'][key] = {"Id": key, "Range": 5, "Value": value['value']}
+
+        outputStream.write(bytearray(json.dumps(newObj, indent=4).encode('utf-8')))
+
+flowFile = session.get()
+if (flowFile != None):
+    flowFile = session.write(flowFile,PyStreamCallback())
+    flowFile = session.putAttribute(flowFile, "filename", flowFile.getAttribute('filename').split('.')[0]+'_translated.json')
+    session.transfer(flowFile, REL_SUCCESS)