org.apache.camel.impl.engine.CamelPostProcessorHelper Maven / Gradle / Ivy
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* 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
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* 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,
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package org.apache.camel.impl.engine;
import java.lang.reflect.Method;
import java.util.Set;
import org.apache.camel.CamelContext;
import org.apache.camel.CamelContextAware;
import org.apache.camel.Consume;
import org.apache.camel.Consumer;
import org.apache.camel.ConsumerTemplate;
import org.apache.camel.DelegateEndpoint;
import org.apache.camel.Endpoint;
import org.apache.camel.ExtendedCamelContext;
import org.apache.camel.FluentProducerTemplate;
import org.apache.camel.IsSingleton;
import org.apache.camel.MultipleConsumersSupport;
import org.apache.camel.NoSuchBeanException;
import org.apache.camel.PollingConsumer;
import org.apache.camel.Producer;
import org.apache.camel.ProducerTemplate;
import org.apache.camel.ProxyInstantiationException;
import org.apache.camel.RuntimeCamelException;
import org.apache.camel.Service;
import org.apache.camel.spi.BeanProxyFactory;
import org.apache.camel.spi.PropertiesComponent;
import org.apache.camel.support.CamelContextHelper;
import org.apache.camel.support.service.ServiceHelper;
import org.apache.camel.util.ObjectHelper;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* A helper class for Camel based injector or post processing hooks which can be
* reused by both the Spring,
* Guice and
* Blueprint support.
*/
public class CamelPostProcessorHelper implements CamelContextAware {
private static final Logger LOG = LoggerFactory.getLogger(CamelPostProcessorHelper.class);
private CamelContext camelContext;
public CamelPostProcessorHelper() {
}
public CamelPostProcessorHelper(CamelContext camelContext) {
this.setCamelContext(camelContext);
}
@Override
public CamelContext getCamelContext() {
return camelContext;
}
@Override
public void setCamelContext(CamelContext camelContext) {
this.camelContext = camelContext;
}
public void consumerInjection(Method method, Object bean, String beanName) {
Consume consume = method.getAnnotation(Consume.class);
if (consume != null) {
LOG.debug("Creating a consumer for: {}", consume);
String uri = consume.value().isEmpty() ? consume.uri() : consume.value();
subscribeMethod(method, bean, beanName, uri, consume.property(), consume.predicate());
}
}
public void subscribeMethod(Method method, Object bean, String beanName, String endpointUri, String endpointProperty, String predicate) {
// lets bind this method to a listener
String injectionPointName = method.getName();
Endpoint endpoint = getEndpointInjection(bean, endpointUri, endpointProperty, injectionPointName, true);
if (endpoint != null) {
boolean multipleConsumer = false;
if (endpoint instanceof MultipleConsumersSupport) {
multipleConsumer = ((MultipleConsumersSupport) endpoint).isMultipleConsumersSupported();
}
try {
SubscribeMethodProcessor processor = getConsumerProcessor(endpoint);
// if multiple consumer then create a new consumer per subscribed method
if (multipleConsumer || processor == null) {
// create new processor and new consumer which happens the first time
processor = new SubscribeMethodProcessor(endpoint);
// make sure processor is registered in registry so we can reuse it (eg we can look it up)
endpoint.getCamelContext().addService(processor, true);
processor.addMethod(bean, method, endpoint, predicate);
Consumer consumer = endpoint.createConsumer(processor);
startService(consumer, endpoint.getCamelContext(), bean, beanName);
} else {
// add method to existing processor
processor.addMethod(bean, method, endpoint, predicate);
}
if (predicate != null) {
LOG.debug("Subscribed method: {} to consume from endpoint: {} with predicate: {}", method, endpoint, predicate);
} else {
LOG.debug("Subscribed method: {} to consume from endpoint: {}", method, endpoint);
}
} catch (Exception e) {
throw RuntimeCamelException.wrapRuntimeCamelException(e);
}
}
}
/**
* Stats the given service
*/
protected void startService(Service service, CamelContext camelContext, Object bean, String beanName) throws Exception {
// defer starting the service until CamelContext has started all its initial services
if (camelContext != null) {
camelContext.deferStartService(service, true);
} else {
// mo CamelContext then start service manually
ServiceHelper.startService(service);
}
boolean singleton = isSingleton(bean, beanName);
if (!singleton) {
LOG.debug("Service is not singleton so you must remember to stop it manually {}", service);
}
}
protected SubscribeMethodProcessor getConsumerProcessor(Endpoint endpoint) {
Set processors = endpoint.getCamelContext().hasServices(SubscribeMethodProcessor.class);
return processors.stream().filter(s -> s.getEndpoint() == endpoint).findFirst().orElse(null);
}
public Endpoint getEndpointInjection(Object bean, String uri, String propertyName,
String injectionPointName, boolean mandatory) {
Endpoint answer;
if (ObjectHelper.isEmpty(uri)) {
// if no uri then fallback and try the endpoint property
answer = doGetEndpointInjection(bean, propertyName, injectionPointName);
} else {
answer = doGetEndpointInjection(uri, injectionPointName, mandatory);
}
// it may be a delegate endpoint via ref component
if (answer instanceof DelegateEndpoint) {
answer = ((DelegateEndpoint) answer).getEndpoint();
}
return answer;
}
private Endpoint doGetEndpointInjection(String uri, String injectionPointName, boolean mandatory) {
return CamelContextHelper.getEndpointInjection(getCamelContext(), uri, injectionPointName, mandatory);
}
/**
* Gets the injection endpoint from a bean property.
*
* @param bean the bean
* @param propertyName the property name on the bean
*/
private Endpoint doGetEndpointInjection(Object bean, String propertyName, String injectionPointName) {
// fall back and use the method name if no explicit property name was given
if (ObjectHelper.isEmpty(propertyName)) {
propertyName = injectionPointName;
}
// we have a property name, try to lookup a getter method on the bean with that name using this strategy
// 1. first the getter with the name as given
// 2. then the getter with Endpoint as postfix
// 3. then if start with on then try step 1 and 2 again, but omit the on prefix
try {
Object value = getCamelContext().adapt(ExtendedCamelContext.class).getBeanIntrospection().getOrElseProperty(bean, propertyName, null, false);
if (value == null) {
// try endpoint as postfix
value = getCamelContext().adapt(ExtendedCamelContext.class).getBeanIntrospection().getOrElseProperty(bean, propertyName + "Endpoint", null, false);
}
if (value == null && propertyName.startsWith("on")) {
// retry but without the on as prefix
propertyName = propertyName.substring(2);
return doGetEndpointInjection(bean, propertyName, injectionPointName);
}
if (value == null) {
return null;
} else if (value instanceof Endpoint) {
return (Endpoint) value;
} else {
String uriOrRef = getCamelContext().getTypeConverter().mandatoryConvertTo(String.class, value);
return getCamelContext().getEndpoint(uriOrRef);
}
} catch (Exception e) {
throw new IllegalArgumentException("Error getting property " + propertyName + " from bean " + bean + " due " + e.getMessage(), e);
}
}
/**
* Creates the object to be injected for an
* {@link org.apache.camel.EndpointInject} or
* {@link org.apache.camel.Produce} injection point
*/
public Object getInjectionValue(Class type, String endpointUri, String endpointProperty,
String injectionPointName, Object bean, String beanName) {
return getInjectionValue(type, endpointUri, endpointProperty, injectionPointName, bean, beanName, true);
}
/**
* Creates the object to be injected for an
* {@link org.apache.camel.EndpointInject} or
* {@link org.apache.camel.Produce} injection point
*/
@SuppressWarnings("unchecked")
public Object getInjectionValue(Class type, String endpointUri, String endpointProperty,
String injectionPointName, Object bean, String beanName, boolean binding) {
if (type.isAssignableFrom(ProducerTemplate.class)) {
return createInjectionProducerTemplate(endpointUri, endpointProperty, injectionPointName, bean);
} else if (type.isAssignableFrom(FluentProducerTemplate.class)) {
return createInjectionFluentProducerTemplate(endpointUri, endpointProperty, injectionPointName, bean);
} else if (type.isAssignableFrom(ConsumerTemplate.class)) {
return createInjectionConsumerTemplate(endpointUri, endpointProperty, injectionPointName);
} else {
Endpoint endpoint = getEndpointInjection(bean, endpointUri, endpointProperty, injectionPointName, true);
if (endpoint != null) {
if (type.isInstance(endpoint)) {
return endpoint;
} else if (type.isAssignableFrom(Producer.class)) {
return createInjectionProducer(endpoint, bean, beanName);
} else if (type.isAssignableFrom(PollingConsumer.class)) {
return createInjectionPollingConsumer(endpoint, bean, beanName);
} else if (type.isInterface()) {
// lets create a proxy
try {
// use proxy service
BeanProxyFactory factory = endpoint.getCamelContext().adapt(ExtendedCamelContext.class).getBeanProxyFactory();
if (factory == null) {
throw new IllegalArgumentException("Cannot find BeanProxyFactory. Make sure camel-bean is on the classpath.");
}
return factory.createProxy(endpoint, binding, type);
} catch (Exception e) {
throw createProxyInstantiationRuntimeException(type, endpoint, e);
}
} else {
throw new IllegalArgumentException("Invalid type: " + type.getName()
+ " which cannot be injected via @EndpointInject/@Produce for: " + endpoint);
}
}
return null;
}
}
public Object getInjectionPropertyValue(Class type, String propertyName, String propertyDefaultValue,
String injectionPointName, Object bean, String beanName) {
try {
String key;
String prefix = PropertiesComponent.PREFIX_TOKEN;
String suffix = PropertiesComponent.SUFFIX_TOKEN;
if (!propertyName.contains(prefix)) {
// must enclose the property name with prefix/suffix to have it resolved
key = prefix + propertyName + suffix;
} else {
// key has already prefix/suffix so use it as-is as it may be a compound key
key = propertyName;
}
String value = getCamelContext().resolvePropertyPlaceholders(key);
if (value != null) {
return getCamelContext().getTypeConverter().mandatoryConvertTo(type, value);
} else {
return null;
}
} catch (Exception e) {
if (ObjectHelper.isNotEmpty(propertyDefaultValue)) {
try {
return getCamelContext().getTypeConverter().mandatoryConvertTo(type, propertyDefaultValue);
} catch (Exception e2) {
throw RuntimeCamelException.wrapRuntimeCamelException(e2);
}
}
throw RuntimeCamelException.wrapRuntimeCamelException(e);
}
}
public Object getInjectionBeanValue(Class type, String name) {
if (ObjectHelper.isEmpty(name)) {
// is it camel context itself?
if (type.isAssignableFrom(camelContext.getClass())) {
return camelContext;
}
Set found = getCamelContext().getRegistry().findByType(type);
if (found == null || found.isEmpty()) {
throw new NoSuchBeanException(name, type.getName());
} else if (found.size() > 1) {
throw new NoSuchBeanException("Found " + found.size() + " beans of type: " + type + ". Only one bean expected.");
} else {
// we found only one
return found.iterator().next();
}
} else {
return CamelContextHelper.mandatoryLookup(getCamelContext(), name, type);
}
}
/**
* Factory method to create a {@link org.apache.camel.ProducerTemplate} to
* be injected into a POJO
*/
protected ProducerTemplate createInjectionProducerTemplate(String endpointUri, String endpointProperty,
String injectionPointName, Object bean) {
// endpoint is optional for this injection point
Endpoint endpoint = getEndpointInjection(bean, endpointUri, endpointProperty, injectionPointName, false);
CamelContext context = endpoint != null ? endpoint.getCamelContext() : getCamelContext();
ProducerTemplate answer = new DefaultProducerTemplate(context, endpoint);
// start the template so its ready to use
try {
// no need to defer the template as it can adjust to the endpoint at runtime
startService(answer, context, bean, null);
} catch (Exception e) {
throw RuntimeCamelException.wrapRuntimeCamelException(e);
}
return answer;
}
/**
* Factory method to create a
* {@link org.apache.camel.FluentProducerTemplate} to be injected into a
* POJO
*/
protected FluentProducerTemplate createInjectionFluentProducerTemplate(String endpointUri, String endpointProperty,
String injectionPointName, Object bean) {
// endpoint is optional for this injection point
Endpoint endpoint = getEndpointInjection(bean, endpointUri, endpointProperty, injectionPointName, false);
CamelContext context = endpoint != null ? endpoint.getCamelContext() : getCamelContext();
FluentProducerTemplate answer = new DefaultFluentProducerTemplate(context);
answer.setDefaultEndpoint(endpoint);
// start the template so its ready to use
try {
// no need to defer the template as it can adjust to the endpoint at runtime
startService(answer, context, bean, null);
} catch (Exception e) {
throw RuntimeCamelException.wrapRuntimeCamelException(e);
}
return answer;
}
/**
* Factory method to create a {@link org.apache.camel.ConsumerTemplate} to
* be injected into a POJO
*/
protected ConsumerTemplate createInjectionConsumerTemplate(String endpointUri, String endpointProperty,
String injectionPointName) {
ConsumerTemplate answer = new DefaultConsumerTemplate(getCamelContext());
// start the template so its ready to use
try {
startService(answer, null, null, null);
} catch (Exception e) {
throw RuntimeCamelException.wrapRuntimeCamelException(e);
}
return answer;
}
/**
* Factory method to create a started
* {@link org.apache.camel.PollingConsumer} to be injected into a POJO
*/
protected PollingConsumer createInjectionPollingConsumer(Endpoint endpoint, Object bean, String beanName) {
try {
PollingConsumer consumer = endpoint.createPollingConsumer();
startService(consumer, endpoint.getCamelContext(), bean, beanName);
return consumer;
} catch (Exception e) {
throw RuntimeCamelException.wrapRuntimeCamelException(e);
}
}
/**
* A Factory method to create a started {@link org.apache.camel.Producer} to
* be injected into a POJO
*/
protected Producer createInjectionProducer(Endpoint endpoint, Object bean, String beanName) {
try {
return endpoint.getCamelContext().adapt(ExtendedCamelContext.class).getDeferServiceFactory().createProducer(endpoint);
} catch (Exception e) {
throw RuntimeCamelException.wrapRuntimeCamelException(e);
}
}
protected RuntimeException createProxyInstantiationRuntimeException(Class type, Endpoint endpoint, Exception e) {
return new ProxyInstantiationException(type, endpoint, e);
}
/**
* Implementations can override this method to determine if the bean is
* singleton.
*
* @param bean the bean
* @return true if its singleton scoped, for prototype scoped
* false is returned.
*/
protected boolean isSingleton(Object bean, String beanName) {
if (bean instanceof IsSingleton) {
IsSingleton singleton = (IsSingleton) bean;
return singleton.isSingleton();
}
return true;
}
}
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