1 /*
2 * Copyright 2009 the original author or authors.
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16 package org.openehealth.ipf.platform.camel.core.model;
17
18 import java.util.ArrayList;
19 import java.util.List;
20
21 import org.apache.camel.Processor;
22 import org.apache.camel.model.OutputDefinition;
23 import org.apache.camel.model.RouteDefinition;
24 import org.apache.camel.processor.DelegateProcessor;
25 import org.apache.camel.processor.Pipeline;
26 import org.apache.camel.spi.RouteContext;
27
28 import javax.xml.bind.annotation.XmlAccessType;
29 import javax.xml.bind.annotation.XmlAccessorType;
30
31 /**
32 * An {@link OutputDefinition} that combines the {@link Processor} created by
33 * {@link #doCreateDelegate(RouteContext)} and the child processor created by
34 * {@link #createChildProcessor} into a {@link Pipeline}.
35 * This base class supports the implementation of parameterizable DSL extensions
36 * without forcing implementors to create {@link DelegateProcessor} instances.
37 * Instead, plain {@link Processor} instances can be returned by
38 * {@link #doCreateDelegate(RouteContext)} implementations.
39 *
40 * @author Martin Krasser
41 */
42 @XmlAccessorType(XmlAccessType.FIELD)
43 public abstract class DelegateDefinition extends OutputDefinition<RouteDefinition> {
44
45 @Override
46 public Processor createProcessor(RouteContext routeContext) throws Exception {
47 Processor delegate = doCreateDelegate(routeContext);
48 Processor next = createChildProcessor(routeContext, false);
49
50 List<Processor> processors = new ArrayList<>();
51 processors.add(delegate);
52 if (next != null) {
53 processors.add(next);
54 }
55 return Pipeline.newInstance(routeContext.getCamelContext(), processors);
56 }
57
58 /**
59 * Creates a {@link Processor} for this DSL element.
60 *
61 * @param routeContext
62 * the current route context.
63 * @return a {@link Processor} instance.
64 * @throws Exception
65 */
66 protected abstract Processor doCreateDelegate(RouteContext routeContext);
67
68 }