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Java > Open Source Codes > org > apache > cocoon > components > treeprocessor > SimpleSelectorProcessingNode


1 /*
2  * Copyright 1999-2004 The Apache Software Foundation.
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.apache.cocoon.components.treeprocessor;
17
18 import org.apache.avalon.framework.component.Component;
19 import org.apache.avalon.framework.component.ComponentException;
20 import org.apache.avalon.framework.component.ComponentSelector;
21 import org.apache.avalon.framework.thread.ThreadSafe;
22
23 /**
24  *
25  * @author <a HREF="mailto:sylvain@apache.org">Sylvain Wallez</a>
26  * @version CVS $Id: SimpleSelectorProcessingNode.java 30932 2004-07-29 17:35:38Z vgritsenko $
27  */
28
29 public abstract class SimpleSelectorProcessingNode extends SimpleParentProcessingNode {
30
31     /** The node component name (e.g. action name, selector name, etc) */
32     protected String JavaDoc componentName;
33
34     /** Selector where to get components from */
35     protected ComponentSelector selector;
36
37     public SimpleSelectorProcessingNode(String JavaDoc componentName) {
38         this.componentName = componentName;
39     }
40
41     public void setSelector(ComponentSelector selector) throws ComponentException {
42         this.selector = selector;
43     }
44
45     /**
46      * Tests if the component designated by this node using the selector and component name
47      * is <code>ThreadSafe</code>, and return it if true.
48      * <p>
49      * Note : this method must be called <i>after</i> <code>setSelector()</code>.
50      */
51     protected Component getThreadSafeComponent() throws ComponentException {
52         return getThreadSafeComponent(this.componentName);
53     }
54
55     /**
56      * Tests if the component designated by this node using the selector and component name
57      * is <code>ThreadSafe</code>, and return it if true.
58      * <p>
59      * Note : this method must be called <i>after</i> <code>setSelector()</code>.
60      */
61     protected Component getThreadSafeComponent(String JavaDoc name) throws ComponentException {
62         Component component = this.selector.select(name);
63         if (component instanceof ThreadSafe) {
64             return component;
65         } else {
66             this.selector.release(component);
67             return null;
68         }
69     }
70 }
71
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