Github user PuspenduBanerjee commented on a diff in the pull request:
https://github.com/apache/nifi/pull/186#discussion_r51009342
--- Diff:
nifi-nar-bundles/nifi-camel-bundle/nifi-camel-processors/src/main/java/org/apache/nifi/processors/camel/CamelProcessor.java
---
@@ -0,0 +1,240 @@
+/*
+ * 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.camel;
+
+import com.google.common.collect.ImmutableList;
+import com.google.common.collect.ImmutableSet;
+import groovy.lang.GroovyClassLoader;
+
+import java.util.List;
+import java.util.Set;
+import java.util.concurrent.TimeUnit;
+
+import org.apache.camel.CamelContext;
+import org.apache.camel.Exchange;
+import org.apache.camel.ProducerTemplate;
+import org.apache.camel.ServiceStatus;
+import org.apache.camel.impl.DefaultExchange;
+import org.apache.camel.impl.DefaultShutdownStrategy;
+import org.apache.camel.spi.ShutdownStrategy;
+import org.apache.camel.spring.SpringCamelContext;
+import org.apache.commons.lang3.StringUtils;
+import org.apache.commons.lang3.math.NumberUtils;
+import org.apache.nifi.annotation.behavior.InputRequirement;
+import org.apache.nifi.annotation.behavior.InputRequirement.Requirement;
+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.annotation.lifecycle.OnStopped;
+import org.apache.nifi.components.PropertyDescriptor;
+import org.apache.nifi.components.ValidationContext;
+import org.apache.nifi.components.ValidationResult;
+import org.apache.nifi.components.Validator;
+import org.apache.nifi.flowfile.FlowFile;
+import org.apache.nifi.processor.AbstractProcessor;
+import org.apache.nifi.processor.ProcessContext;
+import org.apache.nifi.processor.ProcessSession;
+import org.apache.nifi.processor.ProcessorInitializationContext;
+import org.apache.nifi.processor.Relationship;
+import org.apache.nifi.processor.exception.ProcessException;
+import org.springframework.context.ApplicationContext;
+import org.springframework.context.support.AbstractApplicationContext;
+import org.springframework.context.support.ClassPathXmlApplicationContext;
+import org.springframework.context.support.FileSystemXmlApplicationContext;
+import org.springframework.context.support.GenericXmlApplicationContext;
+import org.springframework.core.io.ByteArrayResource;
+
+/**
+ * This processor runs a Camel Route.
+ */
+@Tags({"camel", "route", "put"})
+@InputRequirement(Requirement.INPUT_ALLOWED)
+@CapabilityDescription("Runs a Camel Route. Each input FlowFile is
converted into a Camel Exchange "
+ + "for processing by configured Route. It exports
ProcessSession to camel exchange header 'nifiSession'")
+public class CamelProcessor extends AbstractProcessor {
+
+ protected static final Relationship SUCCESS = new
Relationship.Builder().name("success")
+ .description("Camel Route has Executed Successfully").build();
+
+ protected static final Relationship FAILURE = new
Relationship.Builder().name("failure")
+ .description("Camel Route has Failed to Execute").build();
+
+ public static final PropertyDescriptor CAMEL_SPRING_CONTEXT_FILE_PATH
= new PropertyDescriptor.Builder()
+ .name("Camel Spring Config File Path")
+ .description("The Classpath where NiFi can find Spring Application
context file"
+ + " Ex:
classpath:/META-INF/camel-application-context.xml")
+
.defaultValue("classpath:/META-INF/camel-application-context.xml").required(true).addValidator(Validator.VALID)
+ .build();
+
+ public static final PropertyDescriptor CAMEL_SPRING_CONTEXT_DEF = new
PropertyDescriptor.Builder()
+ .name("Camel Spring Context Definition")
+ .description("Content of Spring Application context ")
+ .defaultValue("").addValidator(Validator.VALID)
+ .build();
+
+ public static final PropertyDescriptor CAMEL_ENTRY_POINT_URI = new
PropertyDescriptor.Builder()
+ .name("Camel EntryPoint")
+ .description("EntryPoint for NiFi in Camel Route" + " Ex:
direct-vm:nifiEntryPoint")
+
.defaultValue("direct-vm:nifiEntryPoint").required(true).addValidator(Validator.VALID).build();
+
+ /**
+ *@see <a href="http://camel.apache.org/grape.html";> Camel Grape
Documentation</a>
+ */
+ public static final PropertyDescriptor EXT_LIBRARIES = new
PropertyDescriptor.Builder()
+ .name("Extra Libraries")
+ .description("Comma Seperated List of Extra Libraries/Features to
Download and Use [ in GroupId/ArtifactId/version format]. "
+ + "Ex: org.apache.camel/camel-mail/2.16.1,\n"
+ + "org.apache.camel/camel-infinispan/2.16.1")
+ .required(false).addValidator(new GrapeGrabValidator()).build();
+
+ private static SpringCamelContext camelContext = null;
+
+ private ImmutableList<PropertyDescriptor> descriptors;
+
+ private ImmutableSet<Relationship>
relationships=ImmutableSet.of(SUCCESS, FAILURE);
+
+ public static synchronized SpringCamelContext getCamelContext() {
+ return camelContext;
+ }
+
+ @Override
+ public Set<Relationship> getRelationships() {
+ return relationships;
+ }
+
+ @Override
+ public void onTrigger(final ProcessContext context, final
ProcessSession session) throws ProcessException {
+ FlowFile flowFile = session.get();
+ if (flowFile == null) {
+ return;
+ }
+ CamelContext camelContext=getCamelContext();
+ Exchange exchange = new DefaultExchange(camelContext);
+ exchange.getIn().setBody(flowFile);
+ exchange.getIn().setHeader("nifiSession", session);
+ ProducerTemplate producerTemplate=
camelContext.createProducerTemplate();
+
producerTemplate.setDefaultEndpointUri(context.getProperty(CAMEL_ENTRY_POINT_URI)
+ .getValue());
+ exchange = producerTemplate.send(exchange);
+ try{
+ producerTemplate.stop();
+ }catch(Exception e){
+ throw new ProcessException(e);
+ }
+ if (exchange != null && !(exchange.isFailed())) {
+ session.transfer(exchange.getIn().getBody(FlowFile.class),
SUCCESS);
+ } else {
+ if (exchange.isFailed() && exchange.getException() != null) {
+ session.putAttribute(flowFile, "camelRouteException",
exchange.getException().getMessage());
+ }
+ session.transfer(flowFile, FAILURE);
+ }
+ }
+
+ @Override
+ protected void init(final ProcessorInitializationContext context) {
+ this.descriptors =
ImmutableList.of(CAMEL_SPRING_CONTEXT_FILE_PATH, CAMEL_SPRING_CONTEXT_DEF,
+
CAMEL_ENTRY_POINT_URI,EXT_LIBRARIES);
+ }
+
+ @Override
+ protected List<PropertyDescriptor> getSupportedPropertyDescriptors() {
+ return descriptors;
+ }
+
+ @OnScheduled
+ public void onScheduled(final ProcessContext context) {
+ if (getCamelContext() == null
+ || getCamelContext().getStatus()==ServiceStatus.Stopped
+ || getCamelContext().getStatus()==ServiceStatus.Stopping) {
+ try {
+ String camelContextDef=context
+ .getProperty(CAMEL_SPRING_CONTEXT_DEF).getValue();
+ String camelContextPath=context
+
.getProperty(CAMEL_SPRING_CONTEXT_FILE_PATH).getValue();
+ ApplicationContext applicationContext;
+ if(camelContextDef!=null &&
camelContextDef.trim().length()>0){
+ applicationContext= new
GenericXmlApplicationContext(new
ByteArrayResource(camelContextDef.getBytes(),"InMemory Camel COntext
Definition"));
+ }else{
+ if(camelContextPath.startsWith("classpath:")){
+ applicationContext=new
ClassPathXmlApplicationContext(camelContextPath.split(":")[1]);
+ }else{
+ applicationContext=new
FileSystemXmlApplicationContext(camelContextPath.split(":")[1]);
+ }
+ }
+ camelContext = new SpringCamelContext(applicationContext);
+ camelContext.setApplicationContextClassLoader(new
GroovyClassLoader(camelContext.getApplicationContextClassLoader()));
+ camelContext.addStartupListener(new
CamelContextStartupListener(getLogger()));
+ ShutdownStrategy shutdownStrategy=new
DefaultShutdownStrategy();
+ shutdownStrategy.setTimeout(1);
+ shutdownStrategy.setTimeUnit(TimeUnit.SECONDS);
+ camelContext.setShutdownStrategy(shutdownStrategy);
+ camelContext.start();
+ getLogger().info("Camel Spring Context initialized");
+ } catch (Exception exception) {
+ getLogger().error("Failed to Shutdown Camel Spring
Context", exception);
+ }
+ }
+
+ }
+
+ @OnStopped
+ public void stopped(){
+ if (getCamelContext() != null) {
+ try {
+ getCamelContext().stop();
+ getCamelContext().destroy();
+
((AbstractApplicationContext)getCamelContext().getApplicationContext()).close();
--- End diff --
Agreed. But I think, that shutdown will be quite abrupt. So chosen to
invoke a stop & close. Please correct me otherwise.
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