/*
* Copyright 2013 the original author or authors.
*
* Licensed 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.springframework.xd.module.core;
import java.util.ArrayList;
import java.util.List;
import java.util.Properties;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.concurrent.atomic.AtomicInteger;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.beans.BeansException;
import org.springframework.beans.factory.xml.XmlBeanDefinitionReader;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationListener;
import org.springframework.context.ConfigurableApplicationContext;
import org.springframework.context.support.GenericApplicationContext;
import org.springframework.context.support.PropertySourcesPlaceholderConfigurer;
import org.springframework.core.env.PropertiesPropertySource;
import org.springframework.core.env.PropertySource;
import org.springframework.core.io.Resource;
import org.springframework.integration.config.ConsumerEndpointFactoryBean;
import org.springframework.integration.endpoint.AbstractEndpoint;
import org.springframework.integration.handler.BridgeHandler;
import org.springframework.messaging.MessageChannel;
import org.springframework.util.Assert;
import org.springframework.xd.module.ModuleDeploymentProperties;
import org.springframework.xd.module.ModuleDescriptor;
import org.springframework.xd.module.ModuleType;
/**
* @author Mark Fisher
* @author David Turanski
*/
public class CompositeModule extends AbstractModule {
public static final String OPTION_SEPARATOR = ".";
private final Log logger = LogFactory.getLog(this.getClass());
private final GenericApplicationContext context = new GenericApplicationContext();
private final List<Module> modules;
private final Properties properties = new Properties();
private final AtomicInteger propertiesCounter = new AtomicInteger();
private final AtomicBoolean isRunning = new AtomicBoolean();
public CompositeModule(ModuleDescriptor descriptor, ModuleDeploymentProperties deploymentProperties,
List<Module> modules) {
super(descriptor, deploymentProperties);
this.modules = modules;
this.validate();
}
//TODO: This is specific to XD stream composition. Eventually we may want to support more generic composite modules.
private void validate() {
Assert.isTrue(modules != null && modules.size() > 0, "at least one module required");
ModuleType inferredType = null;
if (modules.size() == 1) {
inferredType = modules.get(0).getType();
}
else {
ModuleType firstType = modules.get(0).getType();
ModuleType lastType = modules.get(modules.size() - 1).getType();
boolean hasInput = firstType != ModuleType.source;
boolean hasOutput = lastType != ModuleType.sink;
if (hasInput && hasOutput) {
inferredType = ModuleType.processor;
}
else if (hasInput) {
inferredType = ModuleType.sink;
}
else if (hasOutput) {
inferredType = ModuleType.source;
}
}
Assert.isTrue(inferredType == this.getType(),
"invalid composite module: inferred type=" + inferredType + ", stated type=" + this.getType());
}
@Override
public void initialize() {
List<AbstractEndpoint> endpoints = new ArrayList<AbstractEndpoint>();
MessageChannel previousOutputChannel = null;
for (int i = 0; i < this.modules.size(); i++) {
Module module = this.modules.get(i);
module.initialize();
MessageChannel inputChannel = module.getComponent("input", MessageChannel.class);
MessageChannel outputChannel = module.getComponent("output", MessageChannel.class);
if (i == 0 && inputChannel != null) {
// this will act as THE input for the composite module
// if the first module has no input, the composite is a source
this.context.getBeanFactory().registerSingleton("input", inputChannel);
}
if (i > 0) {
// first module MAY have 'input', all others MUST
Assert.notNull(inputChannel, "each module after the first must provide 'input'");
}
if (previousOutputChannel != null) {
BridgeHandler handler = new BridgeHandler();
handler.setBeanFactory(this.context.getBeanFactory());
handler.setOutputChannel(inputChannel);
handler.afterPropertiesSet();
ConsumerEndpointFactoryBean bridgeFactoryBean = new ConsumerEndpointFactoryBean();
bridgeFactoryBean.setInputChannel(previousOutputChannel);
bridgeFactoryBean.setHandler(handler);
try {
// TODO: might not be necessary to pass this context, but the FB requires non-null
bridgeFactoryBean.setBeanFactory(this.context.getBeanFactory());
bridgeFactoryBean.afterPropertiesSet();
AbstractEndpoint endpoint = bridgeFactoryBean.getObject();
endpoints.add(endpoint);
this.context.getBeanFactory().registerSingleton("bridge-" + i, endpoint);
endpoint.setComponentName("bridge-" + i);
endpoint.afterPropertiesSet();
}
catch (Exception e) {
throw new IllegalStateException("failed to start bridge for CompositeModule", e);
}
}
if (i < this.modules.size() - 1) {
// last module MAY have 'output', all others MUST
Assert.notNull(outputChannel, "each module before the last must provide 'output'");
}
previousOutputChannel = outputChannel;
if (i == this.modules.size() - 1 && outputChannel != null) {
// this will act as THE output for the composite module
// if the final module has no outputChannel, the composite is a sink
this.context.getBeanFactory().registerSingleton("output", outputChannel);
}
}
for (int i = endpoints.size() - 1; i >= 0; i--) {
endpoints.get(i).start();
}
initContext();
if (logger.isInfoEnabled()) {
logger.info("initialized module: " + this.toString());
}
}
@Override
public ConfigurableApplicationContext getApplicationContext() {
return context;
}
private void initContext() {
Assert.state(context != null, "An ApplicationContext is required");
boolean propertyConfigurerPresent = false;
for (String name : context.getBeanDefinitionNames()) {
if (name.startsWith("org.springframework.context.support.PropertySourcesPlaceholderConfigurer")) {
propertyConfigurerPresent = true;
break;
}
}
if (!propertyConfigurerPresent) {
PropertySourcesPlaceholderConfigurer placeholderConfigurer = new PropertySourcesPlaceholderConfigurer();
placeholderConfigurer.setEnvironment(context.getEnvironment());
context.addBeanFactoryPostProcessor(placeholderConfigurer);
}
context.setId(this.toString());
context.refresh();
}
@Override
public void setParentContext(ApplicationContext parentContext) {
this.context.setParent(parentContext);
}
@Override
public void addListener(ApplicationListener<?> listener) {
for (Module module : modules) {
module.addListener(listener);
}
}
@Override
public void addSource(Object source) {
Assert.notNull(source,"source cannot be null");
Assert.isInstanceOf(Resource.class,source,"unsupported source: " + source.getClass().getName());
Resource resource = (Resource)source;
XmlBeanDefinitionReader reader = new XmlBeanDefinitionReader(this.context);
reader.loadBeanDefinitions(resource);
}
@Override
public void addProperties(Properties properties) {
this.registerPropertySource(properties);
this.properties.putAll(properties);
for (Module module : this.modules) {
module.addProperties(properties);
}
}
private void registerPropertySource(Properties properties) {
int propertiesIndex = this.propertiesCounter.getAndIncrement();
String propertySourceName = "properties-" + propertiesIndex;
PropertySource<?> propertySource = new PropertiesPropertySource(propertySourceName, properties);
this.context.getEnvironment().getPropertySources().addLast(propertySource);
}
@Override
public Properties getProperties() {
return this.properties;
}
@Override
public <T> T getComponent(Class<T> requiredType) {
return (this.context.isActive()) ? this.context.getBean(requiredType) : null;
}
@Override
public <T> T getComponent(String componentName, Class<T> requiredType) {
if (this.context.isActive() && this.context.containsBean(componentName)) {
return context.getBean(componentName, requiredType);
}
return null;
}
@Override
public void destroy() {
for (Module module : this.modules) {
module.destroy();
}
if (this.context != null) {
this.context.destroy();
}
}
/*
* Lifecycle implementation
*/
@Override
public void start() {
Assert.state(this.context != null, "An ApplicationContext is required");
if (this.isRunning.compareAndSet(false, true)) {
for (int i = this.modules.size() - 1; i >= 0; i--) {
Module module = this.modules.get(i);
module.start();
}
try {
this.context.start();
}
catch (BeansException be) {
this.context.destroy();
throw be;
}
if (logger.isInfoEnabled()) {
logger.info("started module: " + this.toString());
}
}
}
@Override
public void stop() {
if (this.isRunning.compareAndSet(true, false)) {
for (Module module : this.modules) {
module.stop();
}
this.context.stop();
if (logger.isInfoEnabled()) {
logger.info("stopped module: " + this.toString());
}
}
}
@Override
public boolean isRunning() {
return isRunning.get();
}
}