1 /***
2 *
3 * Copyright 2004 Protique Ltd
4 *
5 * Licensed under the Apache License, Version 2.0 (the "License");
6 * you may not use this file except in compliance with the License.
7 * You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 *
17 **/
18 package org.codehaus.activespace.query.groovy;
19
20 import groovy.lang.Binding;
21 import groovy.lang.GroovyShell;
22 import org.codehaus.activespace.query.QueryContext;
23 import org.codehaus.activespace.query.QueryException;
24 import org.codehaus.activespace.query.QueryManager;
25 import org.codehaus.groovy.runtime.InvokerHelper;
26
27 import java.util.List;
28
29 /***
30 * An implementation of the QueryManager using <a href="http://groovy.codehaus.org/">Groovy</a>
31 *
32 * @version $Revision: 1.1 $
33 */
34 public class GroovyQueryManager implements QueryManager {
35
36 public List select(String query, QueryContext context) throws QueryException {
37 Object answer = evaluate(query, context);
38 return InvokerHelper.asList(answer);
39 }
40
41 public Object evaluate(String query, QueryContext context) throws QueryException {
42 GroovyShell shell = createShell(context);
43 try {
44 return shell.evaluate(query);
45 }
46 catch (Exception e) {
47 throw new QueryException("Failed to perform query '" + query + "' due to: " + e, e);
48 }
49 }
50
51 protected GroovyShell createShell(final QueryContext context) {
52 GroovyShell shell = new GroovyShell(new Binding() {
53 public Object getProperty(String name) {
54 return context.getValue(name);
55 }
56
57 public Object getVariable(String name) {
58 return context.getValue(name);
59 }
60 });
61 return shell;
62 }
63 }