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<>(endpoint.getEndpointPropertyNames());
053        propertyNamesInterceptor.interceptPropertyNames(argNames);
054
055        List<ApiMethod> filteredMethods = endpoint.methodHelper.filterMethods(
056                endpoint.getCandidates(), ApiMethodHelper.MatchType.SUPER_SET, argNames);
057
058        if (filteredMethods.isEmpty()) {
059            ApiMethodHelper<? extends ApiMethod> methodHelper = endpoint.getMethodHelper();
060            throw new IllegalArgumentException(
061                    String.format("Missing properties for %s/%s, need one or more from %s",
062                            endpoint.getApiName().getName(), endpoint.getMethodName(),
063                            methodHelper.getMissingProperties(endpoint.getMethodName(), argNames)));
064        } else if (filteredMethods.size() == 1) {
065            // single match
066            result = filteredMethods.get(0);
067        } else {
068            result = ApiMethodHelper.getHighestPriorityMethod(filteredMethods);
069            LOG.warn(String.format("Using highest priority operation %s from operations %s for endpoint %s",
070                result, filteredMethods, endpoint.getEndpointUri()));
071        }
072
073        return result;
074    }
075
076    /**
077     * Utility method for Consumers to process API method invocation result.
078     * @param consumer Consumer that wants to process results.
079     * @param result result of API method invocation.
080     * @param splitResult true if the Consumer wants to split result using {@link org.apache.camel.util.component.ResultInterceptor#splitResult(Object)} method.
081     * @param <T> Consumer class that extends DefaultConsumer and implements {@link org.apache.camel.util.component.ResultInterceptor}.
082     * @return number of result exchanges processed.
083     * @throws Exception on error.
084     */
085    public static <T extends DefaultConsumer & ResultInterceptor> int getResultsProcessed(
086        T consumer, Object result, boolean splitResult) throws Exception {
087
088        // process result according to type
089        if (result != null && splitResult) {
090            // try to split the result
091            final Object results = consumer.splitResult(result);
092
093            if (results != null) {
094                if (results instanceof List) {
095                    // Optimized for lists
096                    final List<?> list = (List<?>)results;
097                    final int size = list.size();
098
099                    // access elements by position rather than with iterator to
100                    // reduce garbage
101                    for (int i = 0; i < size; i++) {
102                        processResult(consumer, result, list.get(i));
103                    }
104
105                    return size;
106                } else if (results instanceof Iterable) {
107                    // Optimized for iterable
108                    int size = 0;
109                    for (Object singleResult : (Iterable<?>)results) {
110                        processResult(consumer, result, singleResult);
111                        size++;
112                    }
113
114                    return size;
115                } else if (results.getClass().isArray()) {
116                    // Optimized for array
117                    final int size = Array.getLength(results);
118                    for (int i = 0; i < size; i++) {
119                        processResult(consumer, result, Array.get(results, i));
120                    }
121
122                    return size;
123                }
124            }
125        }
126
127        processResult(consumer, result, result);
128        return 1; // number of messages polled
129    }
130
131    private static <T extends DefaultConsumer & ResultInterceptor> void processResult(T consumer, Object methodResult, Object result)
132        throws Exception {
133
134        Exchange exchange = consumer.getEndpoint().createExchange();
135        exchange.getIn().setBody(result);
136
137        consumer.interceptResult(methodResult, exchange);
138        try {
139            // send message to next processor in the route
140            consumer.getProcessor().process(exchange);
141        } finally {
142            // log exception if an exception occurred and was not handled
143            final Exception exception = exchange.getException();
144            if (exception != null) {
145                consumer.getExceptionHandler().handleException("Error processing exchange", exchange, exception);
146            }
147        }
148    }
149}