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 */
017 package org.apache.camel.processor.aggregate;
018
019 import java.lang.reflect.Method;
020 import java.util.ArrayList;
021 import java.util.List;
022
023 import org.apache.camel.CamelContext;
024 import org.apache.camel.Expression;
025 import org.apache.camel.builder.ExpressionBuilder;
026 import org.apache.camel.component.bean.ParameterInfo;
027 import org.slf4j.Logger;
028 import org.slf4j.LoggerFactory;
029
030 /**
031 * Class information about the POJO method to call when using the {@link AggregationStrategyBeanAdapter}.
032 */
033 public class AggregationStrategyBeanInfo {
034
035 // TODO: We could potential merge this logic into AggregationStrategyMethodInfo and only have 1 class
036
037 private static final Logger LOG = LoggerFactory.getLogger(AggregationStrategyBeanInfo.class);
038
039 private final CamelContext camelContext;
040 private final Class<?> type;
041 private final Method method;
042
043 public AggregationStrategyBeanInfo(CamelContext camelContext, Class<?> type, Method method) {
044 this.camelContext = camelContext;
045 this.type = type;
046 this.method = method;
047 }
048
049 protected AggregationStrategyMethodInfo createMethodInfo() {
050 Class<?>[] parameterTypes = method.getParameterTypes();
051
052 int size = parameterTypes.length;
053 if (LOG.isTraceEnabled()) {
054 LOG.trace("Creating MethodInfo for class: {} method: {} having {} parameters", new Object[]{type, method, size});
055 }
056
057 // must have equal number of parameters
058 if (size < 2) {
059 throw new IllegalArgumentException("The method " + method.getName() + " must have at least two parameters, has: " + size);
060 } else if (size % 2 != 0) {
061 throw new IllegalArgumentException("The method " + method.getName() + " must have equal number of parameters, has: " + size);
062 }
063
064 // must not have annotations as they are not supported (yet)
065 for (int i = 0; i < size; i++) {
066 Class<?> type = parameterTypes[i];
067 if (type.getAnnotations().length > 0) {
068 throw new IllegalArgumentException("Parameter annotations at index " + i + " is not supported on method: " + method);
069 }
070 }
071
072 List<ParameterInfo> oldParameters = new ArrayList<ParameterInfo>();
073 List<ParameterInfo> newParameters = new ArrayList<ParameterInfo>();
074
075 for (int i = 0; i < size / 2; i++) {
076 Class<?> oldType = parameterTypes[i];
077 if (oldParameters.size() == 0) {
078 // the first parameter is the body
079 Expression oldBody = ExpressionBuilder.mandatoryBodyExpression(oldType);
080 ParameterInfo info = new ParameterInfo(i, oldType, null, oldBody);
081 oldParameters.add(info);
082 } else if (oldParameters.size() == 1) {
083 // the 2nd parameter is the headers
084 Expression oldHeaders = ExpressionBuilder.headersExpression();
085 ParameterInfo info = new ParameterInfo(i, oldType, null, oldHeaders);
086 oldParameters.add(info);
087 } else if (oldParameters.size() == 2) {
088 // the 3rd parameter is the properties
089 Expression oldProperties = ExpressionBuilder.propertiesExpression();
090 ParameterInfo info = new ParameterInfo(i, oldType, null, oldProperties);
091 oldParameters.add(info);
092 }
093 }
094
095 for (int i = size / 2; i < size; i++) {
096 Class<?> newType = parameterTypes[i];
097 if (newParameters.size() == 0) {
098 // the first parameter is the body
099 Expression newBody = ExpressionBuilder.mandatoryBodyExpression(newType);
100 ParameterInfo info = new ParameterInfo(i, newType, null, newBody);
101 newParameters.add(info);
102 } else if (newParameters.size() == 1) {
103 // the 2nd parameter is the headers
104 Expression newHeaders = ExpressionBuilder.headersExpression();
105 ParameterInfo info = new ParameterInfo(i, newType, null, newHeaders);
106 newParameters.add(info);
107 } else if (newParameters.size() == 2) {
108 // the 3rd parameter is the properties
109 Expression newProperties = ExpressionBuilder.propertiesExpression();
110 ParameterInfo info = new ParameterInfo(i, newType, null, newProperties);
111 newParameters.add(info);
112 }
113 }
114
115 return new AggregationStrategyMethodInfo(camelContext, type, method, oldParameters, newParameters);
116 }
117
118 }