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.util;
018
019 import java.util.ArrayList;
020 import java.util.Collection;
021 import java.util.List;
022
023 import org.apache.camel.CamelContext;
024 import org.apache.camel.Endpoint;
025 import org.apache.camel.Exchange;
026 import org.apache.camel.Expression;
027 import org.apache.camel.NoSuchEndpointException;
028 import org.apache.camel.impl.DefaultCamelContext;
029 import org.apache.camel.spi.Injector;
030 import org.apache.camel.spi.Language;
031 import org.apache.camel.spi.Registry;
032
033 import static org.apache.camel.util.ObjectHelper.isNotNullAndNonEmpty;
034 import static org.apache.camel.util.ObjectHelper.isNullOrBlank;
035 import static org.apache.camel.util.ObjectHelper.notNull;
036 /**
037 * A number of helper methods
038 *
039 * @version $Revision: 747264 $
040 */
041 public final class CamelContextHelper {
042 /**
043 * Utility classes should not have a public constructor.
044 */
045 private CamelContextHelper() {
046 }
047
048 /**
049 * Returns the mandatory endpoint for the given URI or the
050 * {@link org.apache.camel.NoSuchEndpointException} is thrown
051 */
052 public static Endpoint getMandatoryEndpoint(CamelContext camelContext, String uri)
053 throws NoSuchEndpointException {
054 Endpoint endpoint = camelContext.getEndpoint(uri);
055 if (endpoint == null) {
056 throw new NoSuchEndpointException(uri);
057 } else {
058 return endpoint;
059 }
060 }
061
062 /**
063 * Returns the mandatory endpoint for the given URI and type or the
064 * {@link org.apache.camel.NoSuchEndpointException} is thrown
065 */
066 public static <T extends Endpoint> T getMandatoryEndpoint(CamelContext camelContext, String uri, Class<T> type) {
067 Endpoint endpoint = getMandatoryEndpoint(camelContext, uri);
068 return ObjectHelper.cast(type, endpoint);
069 }
070
071 /**
072 * Returns a list of all endpoints of the given type
073 *
074 * @param camelContext the camel context
075 * @param type the type of the endpoints requested
076 * @return a list which may be empty of all the endpoint instances of the
077 * given type
078 */
079 public <T> List<T> getEndpoints(CamelContext camelContext, Class<T> type) {
080 return getEndpointsImpl(camelContext, type, false);
081 }
082
083 /**
084 * Returns a list of all singleton endpoints of the given type
085 *
086 * @param camelContext the camel context
087 * @param type the type of the endpoints requested
088 * @return a list which may be empty of all the endpoint instances of the
089 * given type
090 */
091 public static <T> List<T> getSingletonEndpoints(CamelContext camelContext, Class<T> type) {
092 return getEndpointsImpl(camelContext, type, true);
093 }
094
095 /**
096 * Returns a list of all singleton or regular endpoints of the given type
097 */
098 private static <T> List<T> getEndpointsImpl(CamelContext camelContext, Class<T> type, boolean singleton) {
099 List<T> answer = new ArrayList<T>();
100 Collection<Endpoint> endpoints = singleton ? camelContext.getSingletonEndpoints() : camelContext.getEndpoints();
101 for (Endpoint endpoint : endpoints) {
102 if (type.isInstance(endpoint)) {
103 T value = type.cast(endpoint);
104 answer.add(value);
105 }
106 }
107 return answer;
108 }
109
110 /**
111 * Converts the given value to the requested type
112 */
113 public static <T> T convertTo(CamelContext context, Class<T> type, Object value) {
114 notNull(context, "camelContext");
115 return context.getTypeConverter().convertTo(type, value);
116 }
117
118 /**
119 * Converts the given value to the specified type throwing an {@link IllegalArgumentException}
120 * if the value could not be converted to a non null value
121 */
122 public static <T> T mandatoryConvertTo(CamelContext context, Class<T> type, Object value) {
123 T answer = convertTo(context, type, value);
124 if (answer == null) {
125 throw new IllegalArgumentException("Value " + value + " converted to " + type.getName() + " cannot be null");
126 }
127 return answer;
128 }
129
130 /**
131 * Creates a new instance of the given type using the {@link Injector} on the given
132 * {@link CamelContext}
133 */
134 public static <T> T newInstance(CamelContext context, Class<T> beanType) {
135 return context.getInjector().newInstance(beanType);
136 }
137
138 /**
139 * Look up the given named bean in the {@link Registry} on the
140 * {@link CamelContext}
141 */
142 public static Object lookup(CamelContext context, String name) {
143 return context.getRegistry().lookup(name);
144 }
145
146 /**
147 * Look up the given named bean of the given type in the {@link Registry} on the
148 * {@link CamelContext}
149 */
150 public static <T> T lookup(CamelContext context, String name, Class<T> beanType) {
151 return context.getRegistry().lookup(name, beanType);
152 }
153
154 /**
155 * Look up the given named bean in the {@link Registry} on the
156 * {@link CamelContext} or throws
157 */
158 public static Object mandatoryLookup(CamelContext context, String name) {
159 Object answer = lookup(context, name);
160 notNull(answer, "registry entry called " + name);
161 return answer;
162 }
163
164 /**
165 * Look up the given named bean of the given type in the {@link Registry} on the
166 * {@link CamelContext}
167 */
168 public static <T> T mandatoryLookup(CamelContext context, String name, Class<T> beanType) {
169 T answer = lookup(context, name, beanType);
170 notNull(answer, "registry entry called " + name + " of type " + beanType.getName());
171 return answer;
172 }
173
174 /**
175 * Resolves the given language name into a {@link Language} or throws an exception if it could not be converted
176 */
177 public static Language resolveMandatoryLanguage(CamelContext camelContext, String languageName) {
178 notNull(camelContext, "camelContext");
179 notNull(languageName, "languageName");
180
181 Language language = camelContext.resolveLanguage(languageName);
182 if (language == null) {
183 throw new IllegalArgumentException("Could not resolve language: " + languageName);
184 }
185 return language;
186 }
187
188 /**
189 * Resolves the mandatory language name and expression text into a {@link Expression} instance
190 * throwing an exception if it could not be created
191 */
192 public static Expression resolveMandatoryExpression(CamelContext camelContext, String languageName, String expressionText) {
193 notNull(expressionText, "expressionText");
194
195 Language language = resolveMandatoryLanguage(camelContext, languageName);
196 Expression<Exchange> expression = language.createExpression(expressionText);
197 if (expression == null) {
198 throw new IllegalArgumentException("Could not create expression: " + expressionText + " with language: " + language);
199 }
200 return expression;
201 }
202
203 /**
204 * Evaluates the @EndpointInject annotation using the given context
205 */
206 public static Endpoint getEndpointInjection(CamelContext camelContext, String uri, String name, String injectionPointName, boolean mandatory) {
207 Endpoint endpoint = null;
208 if (isNotNullAndNonEmpty(uri)) {
209 endpoint = camelContext.getEndpoint(uri);
210 } else {
211 if (isNullOrBlank(name)) {
212 name = injectionPointName;
213 }
214 if (mandatory) {
215 endpoint = mandatoryLookup(camelContext, name, Endpoint.class);
216 } else {
217 endpoint = lookup(camelContext, name, Endpoint.class);
218 }
219 }
220 return endpoint;
221 }
222
223 }