Java tutorial
/** * 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.camel.component.cxf.jaxrs; import java.lang.ref.SoftReference; import java.lang.reflect.Method; import java.lang.reflect.ParameterizedType; import java.lang.reflect.Type; import java.util.Collection; import java.util.HashMap; import java.util.List; import java.util.Map; import javax.ws.rs.core.Response; import org.apache.camel.CamelException; import org.apache.camel.Exchange; import org.apache.camel.Message; import org.apache.camel.component.cxf.CxfConstants; import org.apache.camel.component.cxf.CxfOperationException; import org.apache.camel.component.cxf.util.CxfEndpointUtils; import org.apache.camel.impl.DefaultProducer; import org.apache.camel.util.LRUCache; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.apache.cxf.jaxrs.JAXRSServiceFactoryBean; import org.apache.cxf.jaxrs.client.Client; import org.apache.cxf.jaxrs.client.JAXRSClientFactoryBean; import org.apache.cxf.jaxrs.client.WebClient; /** * CxfRsProducer binds a Camel exchange to a CXF exchange, acts as a CXF * JAXRS client, it will turn the normal Object invocation to a RESTful request * according to resource annotation. Any response will be bound to Camel exchange. */ public class CxfRsProducer extends DefaultProducer { private static final Log LOG = LogFactory.getLog(CxfRsProducer.class); private boolean throwException; // using a cache of factory beans instead of setting the address of a single cfb // to avoid concurrent issues private ClientFactoryBeanCache clientFactoryBeanCache; public CxfRsProducer(CxfRsEndpoint endpoint) { super(endpoint); this.throwException = endpoint.isThrowExceptionOnFailure(); clientFactoryBeanCache = new ClientFactoryBeanCache(endpoint.getMaxClientCacheSize()); } public void process(Exchange exchange) throws Exception { if (LOG.isTraceEnabled()) { LOG.trace("Process exchange: " + exchange); } Message inMessage = exchange.getIn(); Boolean httpClientAPI = inMessage.getHeader(CxfConstants.CAMEL_CXF_RS_USING_HTTP_API, Boolean.class); // set the value with endpoint's option if (httpClientAPI == null) { httpClientAPI = ((CxfRsEndpoint) getEndpoint()).isHttpClientAPI(); } if (httpClientAPI.booleanValue()) { invokeHttpClient(exchange); } else { invokeProxyClient(exchange); } } @SuppressWarnings("unchecked") protected void invokeHttpClient(Exchange exchange) throws Exception { Message inMessage = exchange.getIn(); JAXRSClientFactoryBean cfb = clientFactoryBeanCache .get(CxfEndpointUtils.getEffectiveAddress(exchange, ((CxfRsEndpoint) getEndpoint()).getAddress())); WebClient client = cfb.createWebClient(); String httpMethod = inMessage.getHeader(Exchange.HTTP_METHOD, String.class); Class responseClass = inMessage.getHeader(CxfConstants.CAMEL_CXF_RS_RESPONSE_CLASS, Class.class); Type genericType = inMessage.getHeader(CxfConstants.CAMEL_CXF_RS_RESPONSE_GENERIC_TYPE, Type.class); String path = inMessage.getHeader(Exchange.HTTP_PATH, String.class); if (LOG.isTraceEnabled()) { LOG.trace("HTTP method = " + httpMethod); LOG.trace("path = " + path); LOG.trace("responseClass = " + responseClass); } // set the path if (path != null) { client.path(path); } CxfRsEndpoint cxfRsEndpoint = (CxfRsEndpoint) getEndpoint(); // check if there is a query map in the message header Map<String, String> maps = inMessage.getHeader(CxfConstants.CAMEL_CXF_RS_QUERY_MAP, Map.class); if (maps == null) { maps = cxfRsEndpoint.getParameters(); } if (maps != null) { for (Map.Entry<String, String> entry : maps.entrySet()) { client.query(entry.getKey(), entry.getValue()); } } CxfRsBinding binding = cxfRsEndpoint.getBinding(); // set the body Object body = null; if (!"GET".equals(httpMethod)) { // need to check the request object. body = binding.bindCamelMessageBodyToRequestBody(inMessage, exchange); if (LOG.isTraceEnabled()) { LOG.trace("Request body = " + body); } } // set headers client.headers(binding.bindCamelHeadersToRequestHeaders(inMessage.getHeaders(), exchange)); // invoke the client Object response = null; if (responseClass == null || Response.class.equals(responseClass)) { response = client.invoke(httpMethod, body); } else { if (Collection.class.isAssignableFrom(responseClass)) { if (genericType instanceof ParameterizedType) { // Get the collection member type first Type[] actualTypeArguments = ((ParameterizedType) genericType).getActualTypeArguments(); response = client.invokeAndGetCollection(httpMethod, body, (Class) actualTypeArguments[0]); } else { throw new CamelException("Can't find the Collection member type"); } } else { response = client.invoke(httpMethod, body, responseClass); } } //Throw exception on a response > 207 //http://en.wikipedia.org/wiki/List_of_HTTP_status_codes if (throwException) { if (response instanceof Response) { Integer respCode = ((Response) response).getStatus(); if (respCode > 207) { throw populateCxfRsProducerException(exchange, (Response) response, respCode); } } } // set response if (exchange.getPattern().isOutCapable()) { if (LOG.isTraceEnabled()) { LOG.trace("Response body = " + response); } exchange.getOut().setBody(binding.bindResponseToCamelBody(response, exchange)); exchange.getOut().setHeaders(binding.bindResponseHeadersToCamelHeaders(response, exchange)); } } protected void invokeProxyClient(Exchange exchange) throws Exception { Message inMessage = exchange.getIn(); Object[] varValues = inMessage.getHeader(CxfConstants.CAMEL_CXF_RS_VAR_VALUES, Object[].class); String methodName = inMessage.getHeader(CxfConstants.OPERATION_NAME, String.class); Client target = null; JAXRSClientFactoryBean cfb = clientFactoryBeanCache .get(CxfEndpointUtils.getEffectiveAddress(exchange, ((CxfRsEndpoint) getEndpoint()).getAddress())); if (varValues == null) { target = cfb.create(); } else { target = cfb.createWithValues(varValues); } // find out the method which we want to invoke JAXRSServiceFactoryBean sfb = cfb.getServiceFactory(); sfb.getResourceClasses(); Object[] parameters = inMessage.getBody(Object[].class); // get the method Method method = findRightMethod(sfb.getResourceClasses(), methodName, getParameterTypes(parameters)); // Will send out the message to // Need to deal with the sub resource class Object response = method.invoke(target, parameters); if (throwException) { if (response instanceof Response) { Integer respCode = ((Response) response).getStatus(); if (respCode > 207) { throw populateCxfRsProducerException(exchange, (Response) response, respCode); } } } if (exchange.getPattern().isOutCapable()) { exchange.getOut().setBody(response); } } private Method findRightMethod(List<Class<?>> resourceClasses, String methodName, Class[] parameterTypes) throws NoSuchMethodException { Method answer = null; for (Class<?> clazz : resourceClasses) { try { answer = clazz.getMethod(methodName, parameterTypes); } catch (NoSuchMethodException ex) { // keep looking } catch (SecurityException ex) { // keep looking } if (answer != null) { return answer; } } throw new NoSuchMethodException( "Can find the method " + methodName + "withe these parameter " + arrayToString(parameterTypes)); } private Class<?>[] getParameterTypes(Object[] objects) { Class<?>[] answer = new Class[objects.length]; int i = 0; for (Object obj : objects) { answer[i] = obj.getClass(); i++; } return answer; } private String arrayToString(Object[] array) { StringBuilder buffer = new StringBuilder("["); for (Object obj : array) { if (buffer.length() > 2) { buffer.append(","); } buffer.append(obj.toString()); } buffer.append("]"); return buffer.toString(); } protected CxfOperationException populateCxfRsProducerException(Exchange exchange, Response response, int responseCode) { CxfOperationException exception; String uri = exchange.getFromEndpoint().getEndpointUri(); String statusText = Response.Status.fromStatusCode(responseCode).toString(); Map<String, String> headers = parseResponseHeaders(response, exchange); String copy = response.toString(); LOG.warn(headers); if (responseCode >= 300 && responseCode < 400) { String redirectLocation; if (response.getMetadata().getFirst("Location") != null) { redirectLocation = response.getMetadata().getFirst("location").toString(); exception = new CxfOperationException(uri, responseCode, statusText, redirectLocation, headers, copy); } else { //no redirect location exception = new CxfOperationException(uri, responseCode, statusText, null, headers, copy); } } else { //internal server error(error code 500) exception = new CxfOperationException(uri, responseCode, statusText, null, headers, copy); } return exception; } protected Map<String, String> parseResponseHeaders(Object response, Exchange camelExchange) { Map<String, String> answer = new HashMap<String, String>(); if (response instanceof Response) { for (Map.Entry<String, List<Object>> entry : ((Response) response).getMetadata().entrySet()) { if (LOG.isTraceEnabled()) { LOG.trace("Parse external header " + entry.getKey() + "=" + entry.getValue()); } LOG.info("Parse external header " + entry.getKey() + "=" + entry.getValue()); answer.put(entry.getKey(), entry.getValue().get(0).toString()); } } return answer; } /** * Cache contains {@link org.apache.cxf.jaxrs.client.JAXRSClientFactoryBean} */ private class ClientFactoryBeanCache { private LRUCache<String, SoftReference<JAXRSClientFactoryBean>> cache; public ClientFactoryBeanCache(final int maxCacheSize) { this.cache = new LRUCache<String, SoftReference<JAXRSClientFactoryBean>>(maxCacheSize); } public JAXRSClientFactoryBean get(String address) throws Exception { JAXRSClientFactoryBean retval = null; synchronized (cache) { SoftReference<JAXRSClientFactoryBean> ref = cache.get(address); if (ref != null) { retval = ref.get(); } if (retval == null) { retval = ((CxfRsEndpoint) getEndpoint()).createJAXRSClientFactoryBean(address); cache.put(address, new SoftReference<JAXRSClientFactoryBean>(retval)); if (LOG.isTraceEnabled()) { LOG.trace("Created client factory bean and add to cache for address '" + address + "'"); } } else { if (LOG.isTraceEnabled()) { LOG.trace("Retrieved client factory bean from cache for address '" + address + "'"); } } } return retval; } } }