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.model.language;
018
019 import java.util.List;
020
021 import javax.xml.bind.annotation.XmlAccessType;
022 import javax.xml.bind.annotation.XmlAccessorType;
023 import javax.xml.bind.annotation.XmlAttribute;
024 import javax.xml.bind.annotation.XmlID;
025 import javax.xml.bind.annotation.XmlRootElement;
026 import javax.xml.bind.annotation.XmlTransient;
027 import javax.xml.bind.annotation.XmlType;
028 import javax.xml.bind.annotation.XmlValue;
029 import javax.xml.bind.annotation.adapters.CollapsedStringAdapter;
030 import javax.xml.bind.annotation.adapters.XmlJavaTypeAdapter;
031
032 import org.apache.camel.CamelContext;
033 import org.apache.camel.Exchange;
034 import org.apache.camel.Expression;
035 import org.apache.camel.Predicate;
036 import org.apache.camel.builder.PredicateBuilder;
037 import org.apache.camel.impl.DefaultRouteContext;
038 import org.apache.camel.spi.Language;
039 import org.apache.camel.spi.RouteContext;
040 import org.apache.camel.util.CollectionStringBuffer;
041 import org.apache.camel.util.IntrospectionSupport;
042 import org.apache.camel.util.ObjectHelper;
043
044 /**
045 * A useful base class for an expression
046 *
047 * @version $Revision: 790458 $
048 */
049 @XmlRootElement
050 @XmlType(name = "expression")
051 @XmlAccessorType(XmlAccessType.FIELD)
052 public class ExpressionDefinition implements Expression, Predicate {
053 @XmlAttribute
054 @XmlJavaTypeAdapter(CollapsedStringAdapter.class)
055 @XmlID
056 private String id;
057 @XmlValue
058 private String expression;
059 @XmlTransient
060 private Predicate predicate;
061 @XmlTransient
062 private Expression expressionValue;
063 @XmlTransient
064 private ExpressionDefinition expressionType;
065
066 public ExpressionDefinition() {
067 }
068
069 public ExpressionDefinition(String expression) {
070 this.expression = expression;
071 }
072
073 public ExpressionDefinition(Predicate predicate) {
074 this.predicate = predicate;
075 }
076
077 public ExpressionDefinition(Expression expression) {
078 this.expressionValue = expression;
079 }
080
081 public static String getLabel(List<ExpressionDefinition> expressions) {
082 CollectionStringBuffer buffer = new CollectionStringBuffer();
083 for (ExpressionDefinition expression : expressions) {
084 buffer.append(expression.getLabel());
085 }
086 return buffer.toString();
087 }
088
089 @Override
090 public String toString() {
091 StringBuilder sb = new StringBuilder();
092 if (getLanguage() != null) {
093 sb.append(getLanguage()).append("{");
094 }
095 if (getExpression() != null) {
096 sb.append(getExpression());
097 }
098 if (getPredicate() != null) {
099 sb.append(getPredicate().toString());
100 }
101 if (getExpressionValue() != null) {
102 sb.append(getExpressionValue().toString());
103 }
104 if (getLanguage() != null) {
105 sb.append("}");
106 }
107 return sb.toString();
108 }
109
110 public Object evaluate(Exchange exchange) {
111 return evaluate(exchange, Object.class);
112 }
113
114 public <T> T evaluate(Exchange exchange, Class<T> type) {
115 if (expressionValue == null) {
116 RouteContext routeContext = new DefaultRouteContext(exchange.getContext());
117 expressionValue = createExpression(routeContext);
118 }
119 ObjectHelper.notNull(expressionValue, "expressionValue");
120 return expressionValue.evaluate(exchange, type);
121 }
122
123 public void assertMatches(String text, Exchange exchange) throws AssertionError {
124 if (!matches(exchange)) {
125 throw new AssertionError(text + getExpression() + " for exchange: " + exchange);
126 }
127 }
128
129 public boolean matches(Exchange exchange) {
130 if (predicate == null) {
131 RouteContext routeContext = new DefaultRouteContext(exchange.getContext());
132 predicate = createPredicate(routeContext);
133 }
134 ObjectHelper.notNull(predicate, "predicate");
135 return predicate.matches(exchange);
136 }
137
138 public String getLanguage() {
139 return "";
140 }
141
142 public Predicate createPredicate(RouteContext routeContext) {
143 if (predicate == null) {
144 if (expressionType != null) {
145 predicate = expressionType.createPredicate(routeContext);
146 } else if (expressionValue != null) {
147 predicate = PredicateBuilder.toPredicate(expressionValue);
148 } else if (getExpression() != null) {
149 ObjectHelper.notNull("language", getLanguage());
150 CamelContext camelContext = routeContext.getCamelContext();
151 Language language = camelContext.resolveLanguage(getLanguage());
152 predicate = language.createPredicate(getExpression());
153 configurePredicate(routeContext, predicate);
154 }
155 }
156 return predicate;
157 }
158
159 public Expression createExpression(RouteContext routeContext) {
160 if (expressionValue == null) {
161 if (expressionType != null) {
162 expressionValue = expressionType.createExpression(routeContext);
163 } else if (getExpression() != null) {
164 ObjectHelper.notNull("language", getLanguage());
165 CamelContext camelContext = routeContext.getCamelContext();
166 Language language = camelContext.resolveLanguage(getLanguage());
167 expressionValue = language.createExpression(getExpression());
168 configureExpression(routeContext, expressionValue);
169 }
170 }
171 return expressionValue;
172 }
173
174 public String getExpression() {
175 return expression;
176 }
177
178 public void setExpression(String expression) {
179 this.expression = expression;
180 }
181
182 /**
183 * Gets the value of the id property.
184 */
185 public String getId() {
186 return id;
187 }
188
189 /**
190 * Sets the value of the id property.
191 */
192 public void setId(String value) {
193 this.id = value;
194 }
195
196 public Predicate getPredicate() {
197 return predicate;
198 }
199
200 public Expression getExpressionValue() {
201 return expressionValue;
202 }
203
204 protected void setExpressionValue(Expression expressionValue) {
205 this.expressionValue = expressionValue;
206 }
207
208 public ExpressionDefinition getExpressionType() {
209 return expressionType;
210 }
211
212 /**
213 * Returns some descriptive text to describe this node
214 */
215 public String getLabel() {
216 String language = getExpression();
217 if (ObjectHelper.isEmpty(language)) {
218 Predicate predicate = getPredicate();
219 if (predicate != null) {
220 return predicate.toString();
221 }
222 Expression expressionValue = getExpressionValue();
223 if (expressionValue != null) {
224 return expressionValue.toString();
225 }
226 } else {
227 return language;
228 }
229 return "";
230 }
231
232 /**
233 * Allows derived classes to set a lazily created expressionType instance
234 * such as if using the {@link org.apache.camel.builder.ExpressionClause}
235 */
236 protected void setExpressionType(ExpressionDefinition expressionType) {
237 this.expressionType = expressionType;
238 }
239
240 protected void configurePredicate(RouteContext routeContext, Predicate predicate) {
241 }
242
243 protected void configureExpression(RouteContext routeContext, Expression expression) {
244 }
245
246 /**
247 * Sets a named property on the object instance using introspection
248 */
249 protected void setProperty(Object bean, String name, Object value) {
250 try {
251 IntrospectionSupport.setProperty(bean, name, value);
252 } catch (Exception e) {
253 throw new IllegalArgumentException("Failed to set property " + name + " on " + bean
254 + ". Reason: " + e, e);
255 }
256 }
257 }