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.ExpressionClause;
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: 705880 $
048 */
049 @XmlRootElement
050 @XmlType(name = "expressionType")
051 @XmlAccessorType(XmlAccessType.FIELD)
052 public class ExpressionType implements Expression<Exchange>, Predicate<Exchange> {
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 ExpressionType expressionType;
065
066 public ExpressionType() {
067 }
068
069 public ExpressionType(String expression) {
070 this.expression = expression;
071 }
072
073 public ExpressionType(Predicate predicate) {
074 this.predicate = predicate;
075 }
076
077 public ExpressionType(Expression expression) {
078 this.expressionValue = expression;
079 }
080
081 public static String getLabel(List<ExpressionType> expressions) {
082 CollectionStringBuffer buffer = new CollectionStringBuffer();
083 for (ExpressionType 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() + "{");
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 if (expressionValue == null) {
112 RouteContext routeContext = new DefaultRouteContext(exchange.getContext());
113 expressionValue = createExpression(routeContext);
114 }
115 ObjectHelper.notNull(expressionValue, "expressionValue");
116 return expressionValue.evaluate(exchange);
117 }
118
119 public void assertMatches(String text, Exchange exchange) throws AssertionError {
120 if (!matches(exchange)) {
121 throw new AssertionError(text + getExpression() + " for exchange: " + exchange);
122 }
123 }
124
125 public boolean matches(Exchange exchange) {
126 if (predicate == null) {
127 RouteContext routeContext = new DefaultRouteContext(exchange.getContext());
128 predicate = createPredicate(routeContext);
129 }
130 ObjectHelper.notNull(predicate, "predicate");
131 return predicate.matches(exchange);
132 }
133
134 public String getLanguage() {
135 return "";
136 }
137
138 public Predicate<Exchange> createPredicate(RouteContext routeContext) {
139 if (predicate == null) {
140 if (expressionType != null) {
141 predicate = expressionType.createPredicate(routeContext);
142 } else {
143 CamelContext camelContext = routeContext.getCamelContext();
144 Language language = camelContext.resolveLanguage(getLanguage());
145 predicate = language.createPredicate(getExpression());
146 configurePredicate(routeContext, predicate);
147 }
148 }
149 return predicate;
150 }
151
152 public Expression createExpression(RouteContext routeContext) {
153 if (expressionValue == null) {
154 if (expressionType != null) {
155 expressionValue = expressionType.createExpression(routeContext);
156 } else {
157 CamelContext camelContext = routeContext.getCamelContext();
158 Language language = camelContext.resolveLanguage(getLanguage());
159 expressionValue = language.createExpression(getExpression());
160 configureExpression(routeContext, expressionValue);
161 }
162 }
163 return expressionValue;
164 }
165
166 public String getExpression() {
167 return expression;
168 }
169
170 public void setExpression(String expression) {
171 this.expression = expression;
172 }
173
174 /**
175 * Gets the value of the id property.
176 */
177 public String getId() {
178 return id;
179 }
180
181 /**
182 * Sets the value of the id property.
183 */
184 public void setId(String value) {
185 this.id = value;
186 }
187
188 public Predicate getPredicate() {
189 return predicate;
190 }
191
192 public Expression getExpressionValue() {
193 return expressionValue;
194 }
195
196 protected void setExpressionValue(Expression expressionValue) {
197 this.expressionValue = expressionValue;
198 }
199
200 /**
201 * Returns some descriptive text to describe this node
202 */
203 public String getLabel() {
204 String language = getExpression();
205 if (ObjectHelper.isNullOrBlank(language)) {
206 Predicate predicate = getPredicate();
207 if (predicate != null) {
208 return predicate.toString();
209 }
210 Expression expressionValue = getExpressionValue();
211 if (expressionValue != null) {
212 return expressionValue.toString();
213 }
214 } else {
215 return language;
216 }
217 return "";
218 }
219
220 /**
221 * Allows derived classes to set a lazily created expressionType instance
222 * such as if using the {@link ExpressionClause}
223 */
224 protected void setExpressionType(ExpressionType expressionType) {
225 this.expressionType = expressionType;
226 }
227
228 protected void configurePredicate(RouteContext routeContext, Predicate predicate) {
229 }
230
231 protected void configureExpression(RouteContext routeContext, Expression expression) {
232 }
233
234 /**
235 * Sets a named property on the object instance using introspection
236 */
237 protected void setProperty(Object bean, String name, Object value) {
238 try {
239 IntrospectionSupport.setProperty(bean, name, value);
240 } catch (Exception e) {
241 throw new IllegalArgumentException("Failed to set property " + name + " on " + bean
242 + ". Reason: " + e, e);
243 }
244 }
245 }