1 /*
2 * Copyright 2008 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.adapter;
17
18 import groovy.lang.Closure;
19 import groovy.transform.stc.ClosureParams;
20 import groovy.transform.stc.SimpleType;
21 import org.apache.camel.Exchange;
22 import org.apache.camel.Expression;
23 import org.apache.camel.Message;
24 import org.openehealth.ipf.platform.camel.core.closures.DelegatingExpression;
25
26 import static org.apache.camel.builder.Builder.body;
27
28 /**
29 * Abstract base class for classes that adapt <i>transform support library</i>
30 * interfaces to Apache Camel interfaces.
31 *
32 * @author Martin Krasser
33 */
34 public abstract class AdapterSupport implements Adapter {
35
36 private Expression inputExpression;
37 private Expression paramsExpression;
38
39 /**
40 * Creates an adapter that by default takes input data from the body of the
41 * in-message.
42 *
43 * @see Exchange#getIn()
44 * @see Message#getBody()
45 */
46 public AdapterSupport() {
47 inputExpression = body();
48 }
49
50 /* (non-Javadoc)
51 * @see org.openehealth.ipf.platform.camel.core.adapter.Adapter#input(org.apache.camel.Expression)
52 */
53 @Override
54 public Adapter input(Expression inputExpression) {
55 this.inputExpression = inputExpression;
56 return this;
57 }
58
59 /* (non-Javadoc)
60 * @see org.openehealth.ipf.platform.camel.core.adapter.Adapter#input(groovy.lang.Closure)
61 */
62 @Override
63 public Adapter input(@ClosureParams(value = SimpleType.class, options = { "org.apache.camel.Expression"})
64 Closure inputExpressionLogic) {
65 return input(new DelegatingExpression(inputExpressionLogic));
66 }
67
68 /* (non-Javadoc)
69 * @see org.openehealth.ipf.platform.camel.core.adapter.Adapter#params(org.apache.camel.Expression)
70 */
71 @Override
72 public Adapter params(Expression paramsExpression) {
73 this.paramsExpression = paramsExpression;
74 return this;
75 }
76
77 /* (non-Javadoc)
78 * @see org.openehealth.ipf.platform.camel.core.adapter.Adapter#params(groovy.lang.Closure)
79 */
80 @Override
81 public Adapter params(@ClosureParams(value = SimpleType.class, options = { "org.apache.camel.Expression"})
82 Closure paramsExpressionLogic) {
83 return params(new DelegatingExpression(paramsExpressionLogic));
84 }
85
86 /* (non-Javadoc)
87 * @see org.openehealth.ipf.platform.camel.core.adapter.Adapter#staticParams(java.lang.Object[])
88 */
89 @Override
90 public Adapter staticParams(Object... params) {
91 paramsExpression = new StaticParams(params);
92 return this;
93 }
94
95 /**
96 * Applies the {@link Expression} set by {@link #input(Expression)} to
97 * obtain input data from the <code>exchange</code>.
98 *
99 * @param exchange
100 * message exchange.
101 * @return input data or <code>null</code> if the expression evaluates to
102 * <code>null</code> or the expression object is <code>null</code>.
103 */
104 protected Object adaptInput(Exchange exchange) {
105 if (inputExpression == null) {
106 return null;
107 }
108 return inputExpression.evaluate(exchange, Object.class);
109 }
110
111 /**
112 * Applies the {@link Expression} set by {@link #params(Expression)} (or
113 * implicitly set by {@link #staticParams(Object...)}) to obtain input
114 * params from the <code>exchange</code>.
115 *
116 * @param exchange
117 * message exchange.
118 * @return input data or <code>null</code> if the expression evaluates to
119 * <code>null</code> or the expression object is <code>null</code>.
120 */
121 protected Object adaptParams(Exchange exchange) {
122 if (paramsExpression == null) {
123 return null;
124 }
125 return paramsExpression.evaluate(exchange, Object.class);
126 }
127
128 }