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.Expression; 026 import org.apache.camel.NoSuchEndpointException; 027 import org.apache.camel.spi.Language; 028 029 import static org.apache.camel.util.ObjectHelper.isEmpty; 030 import static org.apache.camel.util.ObjectHelper.isNotEmpty; 031 import static org.apache.camel.util.ObjectHelper.notNull; 032 033 /** 034 * A number of helper methods 035 * 036 * @version $Revision: 751221 $ 037 */ 038 public final class CamelContextHelper { 039 040 /** 041 * Utility classes should not have a public constructor. 042 */ 043 private CamelContextHelper() { 044 } 045 046 /** 047 * Returns the mandatory endpoint for the given URI or the 048 * {@link org.apache.camel.NoSuchEndpointException} is thrown 049 */ 050 public static Endpoint getMandatoryEndpoint(CamelContext camelContext, String uri) 051 throws NoSuchEndpointException { 052 Endpoint endpoint = camelContext.getEndpoint(uri); 053 if (endpoint == null) { 054 throw new NoSuchEndpointException(uri); 055 } else { 056 return endpoint; 057 } 058 } 059 060 /** 061 * Returns the mandatory endpoint for the given URI and type or the 062 * {@link org.apache.camel.NoSuchEndpointException} is thrown 063 */ 064 public static <T extends Endpoint> T getMandatoryEndpoint(CamelContext camelContext, String uri, Class<T> type) { 065 Endpoint endpoint = getMandatoryEndpoint(camelContext, uri); 066 return ObjectHelper.cast(type, endpoint); 067 } 068 069 /** 070 * Returns a list of all endpoints of the given type 071 * 072 * @param camelContext the camel context 073 * @param type the type of the endpoints requested 074 * @return a list which may be empty of all the endpoint instances of the 075 * given type 076 */ 077 public <T> List<T> getEndpoints(CamelContext camelContext, Class<T> type) { 078 return getEndpointsImpl(camelContext, type, false); 079 } 080 081 /** 082 * Returns a list of all singleton endpoints of the given type 083 * 084 * @param camelContext the camel context 085 * @param type the type of the endpoints requested 086 * @return a list which may be empty of all the endpoint instances of the 087 * given type 088 */ 089 public static <T> List<T> getSingletonEndpoints(CamelContext camelContext, Class<T> type) { 090 return getEndpointsImpl(camelContext, type, true); 091 } 092 093 /** 094 * Returns a list of all singleton or regular endpoints of the given type 095 */ 096 private static <T> List<T> getEndpointsImpl(CamelContext camelContext, Class<T> type, boolean singleton) { 097 List<T> answer = new ArrayList<T>(); 098 Collection<Endpoint> endpoints = singleton ? camelContext.getSingletonEndpoints() : camelContext.getEndpoints(); 099 for (Endpoint endpoint : endpoints) { 100 if (type.isInstance(endpoint)) { 101 T value = type.cast(endpoint); 102 answer.add(value); 103 } 104 } 105 return answer; 106 } 107 108 /** 109 * Converts the given value to the requested type 110 */ 111 public static <T> T convertTo(CamelContext context, Class<T> type, Object value) { 112 notNull(context, "camelContext"); 113 return context.getTypeConverter().convertTo(type, value); 114 } 115 116 /** 117 * Converts the given value to the specified type throwing an {@link IllegalArgumentException} 118 * if the value could not be converted to a non null value 119 */ 120 public static <T> T mandatoryConvertTo(CamelContext context, Class<T> type, Object value) { 121 T answer = convertTo(context, type, value); 122 if (answer == null) { 123 throw new IllegalArgumentException("Value " + value + " converted to " + type.getName() + " cannot be null"); 124 } 125 return answer; 126 } 127 128 /** 129 * Creates a new instance of the given type using the {@link org.apache.camel.spi.Injector} on the given 130 * {@link CamelContext} 131 */ 132 public static <T> T newInstance(CamelContext context, Class<T> beanType) { 133 return context.getInjector().newInstance(beanType); 134 } 135 136 /** 137 * Look up the given named bean in the {@link org.apache.camel.spi.Registry} on the 138 * {@link CamelContext} 139 */ 140 public static Object lookup(CamelContext context, String name) { 141 return context.getRegistry().lookup(name); 142 } 143 144 /** 145 * Look up the given named bean of the given type in the {@link org.apache.camel.spi.Registry} on the 146 * {@link CamelContext} 147 */ 148 public static <T> T lookup(CamelContext context, String name, Class<T> beanType) { 149 return context.getRegistry().lookup(name, beanType); 150 } 151 152 /** 153 * Look up the given named bean in the {@link org.apache.camel.spi.Registry} on the 154 * {@link CamelContext} or throws IllegalArgumentException if not found. 155 */ 156 public static Object mandatoryLookup(CamelContext context, String name) { 157 Object answer = lookup(context, name); 158 notNull(answer, "registry entry called " + name); 159 return answer; 160 } 161 162 /** 163 * Look up the given named bean of the given type in the {@link org.apache.camel.spi.Registry} on the 164 * {@link CamelContext} or throws IllegalArgumentException if not found. 165 */ 166 public static <T> T mandatoryLookup(CamelContext context, String name, Class<T> beanType) { 167 T answer = lookup(context, name, beanType); 168 notNull(answer, "registry entry called " + name + " of type " + beanType.getName()); 169 return answer; 170 } 171 172 /** 173 * Resolves the given language name into a {@link Language} or throws an exception if it could not be converted 174 */ 175 public static Language resolveMandatoryLanguage(CamelContext camelContext, String languageName) { 176 notNull(camelContext, "camelContext"); 177 notNull(languageName, "languageName"); 178 179 Language language = camelContext.resolveLanguage(languageName); 180 if (language == null) { 181 throw new IllegalArgumentException("Could not resolve language: " + languageName); 182 } 183 return language; 184 } 185 186 /** 187 * Resolves the mandatory language name and expression text into a {@link Expression} instance 188 * throwing an exception if it could not be created 189 */ 190 public static Expression resolveMandatoryExpression(CamelContext camelContext, String languageName, String expressionText) { 191 notNull(expressionText, "expressionText"); 192 193 Language language = resolveMandatoryLanguage(camelContext, languageName); 194 Expression expression = language.createExpression(expressionText); 195 if (expression == null) { 196 throw new IllegalArgumentException("Could not create expression: " + expressionText + " with language: " + language); 197 } 198 return expression; 199 } 200 201 /** 202 * Evaluates the @EndpointInject annotation using the given context 203 */ 204 public static Endpoint getEndpointInjection(CamelContext camelContext, String uri, String name, String injectionPointName, boolean mandatory) { 205 Endpoint endpoint = null; 206 if (isNotEmpty(uri)) { 207 endpoint = camelContext.getEndpoint(uri); 208 } else { 209 if (isEmpty(name)) { 210 name = injectionPointName; 211 } 212 if (mandatory) { 213 endpoint = mandatoryLookup(camelContext, name, Endpoint.class); 214 } else { 215 endpoint = lookup(camelContext, name, Endpoint.class); 216 } 217 } 218 return endpoint; 219 } 220 221 }