001/**
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017package org.apache.camel.util.component;
018
019import java.lang.reflect.Array;
020import java.util.HashSet;
021import java.util.List;
022import java.util.Set;
023
024import org.apache.camel.Exchange;
025import org.apache.camel.impl.DefaultConsumer;
026import org.slf4j.Logger;
027import org.slf4j.LoggerFactory;
028
029/**
030 * Utility class for API Consumers.
031 */
032public final class ApiConsumerHelper {
033
034    private static final Logger LOG = LoggerFactory.getLogger(ApiConsumerHelper.class);
035
036    private ApiConsumerHelper() {
037    }
038
039    /**
040     * Utility method to find matching API Method for supplied endpoint's configuration properties.
041     * @param endpoint endpoint for configuration properties.
042     * @param propertyNamesInterceptor names interceptor for adapting property names, usually the consumer class itself.
043     * @param <E> ApiName enumeration.
044     * @param <T> Component configuration class.
045     * @return matching ApiMethod.
046     */
047    public static <E extends Enum<E> & ApiName, T> ApiMethod findMethod(
048        AbstractApiEndpoint<E, T> endpoint, PropertyNamesInterceptor propertyNamesInterceptor) {
049
050        ApiMethod result;
051        // find one that takes the largest subset of endpoint parameters
052        final Set<String> argNames = new HashSet<String>();
053        argNames.addAll(endpoint.getEndpointPropertyNames());
054
055        propertyNamesInterceptor.interceptPropertyNames(argNames);
056
057        final String[] argNamesArray = argNames.toArray(new String[argNames.size()]);
058        List<ApiMethod> filteredMethods = endpoint.methodHelper.filterMethods(
059                endpoint.getCandidates(), ApiMethodHelper.MatchType.SUPER_SET, argNamesArray);
060
061        if (filteredMethods.isEmpty()) {
062            ApiMethodHelper<? extends ApiMethod> methodHelper = endpoint.getMethodHelper();
063            throw new IllegalArgumentException(
064                    String.format("Missing properties for %s/%s, need one or more from %s",
065                            endpoint.getApiName().getName(), endpoint.getMethodName(),
066                            methodHelper.getMissingProperties(endpoint.getMethodName(), argNames)));
067        } else if (filteredMethods.size() == 1) {
068            // single match
069            result = filteredMethods.get(0);
070        } else {
071            result = ApiMethodHelper.getHighestPriorityMethod(filteredMethods);
072            LOG.warn(String.format("Using highest priority operation %s from operations %s for endpoint %s",
073                result, filteredMethods, endpoint.getEndpointUri()));
074        }
075
076        return result;
077    }
078
079    /**
080     * Utility method for Consumers to process API method invocation result.
081     * @param consumer Consumer that wants to process results.
082     * @param result result of API method invocation.
083     * @param splitResult true if the Consumer wants to split result using {@link org.apache.camel.util.component.ResultInterceptor#splitResult(Object)} method.
084     * @param <T> Consumer class that extends DefaultConsumer and implements {@link org.apache.camel.util.component.ResultInterceptor}.
085     * @return number of result exchanges processed.
086     * @throws Exception on error.
087     */
088    public static <T extends DefaultConsumer & ResultInterceptor> int getResultsProcessed(
089        T consumer, Object result, boolean splitResult) throws Exception {
090
091        // process result according to type
092        if (result != null && splitResult) {
093            // try to split the result
094            final Object resultArray = consumer.splitResult(result);
095
096            if (resultArray != result && resultArray.getClass().isArray()) {
097                // create an exchange for every element
098                final int length = Array.getLength(resultArray);
099                for (int i = 0; i < length; i++) {
100                    processResult(consumer, result, Array.get(resultArray, i));
101                }
102                return length;
103            }
104        }
105
106        processResult(consumer, result, result);
107        return 1; // number of messages polled
108    }
109
110    private static <T extends DefaultConsumer & ResultInterceptor> void processResult(T consumer, Object methodResult, Object result)
111        throws Exception {
112
113        Exchange exchange = consumer.getEndpoint().createExchange();
114        exchange.getIn().setBody(result);
115
116        consumer.interceptResult(methodResult, exchange);
117        try {
118            // send message to next processor in the route
119            consumer.getProcessor().process(exchange);
120        } finally {
121            // log exception if an exception occurred and was not handled
122            final Exception exception = exchange.getException();
123            if (exception != null) {
124                consumer.getExceptionHandler().handleException("Error processing exchange", exchange, exception);
125            }
126        }
127    }
128}