org.apache.camel.language.ref.RefLanguage Maven / Gradle / Ivy
/**
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.camel.language.ref;
import org.apache.camel.Exchange;
import org.apache.camel.Expression;
import org.apache.camel.IsSingleton;
import org.apache.camel.Predicate;
import org.apache.camel.builder.ExpressionBuilder;
import org.apache.camel.spi.Language;
import org.apache.camel.support.ExpressionAdapter;
import org.apache.camel.util.ExpressionToPredicateAdapter;
/**
* A language for referred expressions.
*/
public class RefLanguage implements Language, IsSingleton {
public static Expression ref(Object value) {
String ref = value.toString();
return ExpressionBuilder.refExpression(ref);
}
public Predicate createPredicate(String expression) {
return ExpressionToPredicateAdapter.toPredicate(createExpression(expression));
}
public Expression createExpression(final String expression) {
final Expression exp = RefLanguage.ref(expression);
return new ExpressionAdapter() {
public Object evaluate(Exchange exchange) {
Expression lookup = exp.evaluate(exchange, Expression.class);
if (lookup != null) {
return lookup.evaluate(exchange, Object.class);
} else {
throw new IllegalArgumentException("Cannot find expression in registry with ref: " + expression);
}
}
public String toString() {
return exp.toString();
}
};
}
public boolean isSingleton() {
return true;
}
}