summaryrefslogtreecommitdiffstats
path: root/sca-java-2.x/tags/2.0.1-RC1/modules/node-impl/src/main/java/org/apache/tuscany/sca/node/extensibility/impl/DefaultNodeActivatorExtensionPoint.java
blob: 8226b120783e78db8a4acc629c33bd11cb185bd9 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
/*
 * 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.tuscany.sca.node.extensibility.impl;

import java.io.IOException;
import java.util.ArrayList;
import java.util.Collection;
import java.util.List;
import java.util.Map;
import java.util.logging.Level;
import java.util.logging.Logger;

import org.apache.tuscany.sca.core.ExtensionPointRegistry;
import org.apache.tuscany.sca.extensibility.ServiceDeclaration;
import org.apache.tuscany.sca.extensibility.ServiceHelper;
import org.apache.tuscany.sca.node.Node;
import org.apache.tuscany.sca.node.extensibility.NodeActivator;
import org.apache.tuscany.sca.node.extensibility.NodeActivatorExtensionPoint;

public class DefaultNodeActivatorExtensionPoint implements NodeActivatorExtensionPoint {
    private final static Logger logger = Logger.getLogger(DefaultNodeActivatorExtensionPoint.class.getName());
    private List<NodeActivator> activators = new ArrayList<NodeActivator>();
    private ExtensionPointRegistry registry;
    private boolean loadedActivators;

    public DefaultNodeActivatorExtensionPoint(ExtensionPointRegistry registry) {
        this.registry = registry;
    }

    public void addNodeActivator(NodeActivator activator) {
        this.activators.add(activator);
    }

    @Override
    public void removeNodeActivator(NodeActivator activator) {
        this.activators.remove(activator);
    }

    @Override
    public List<NodeActivator> getNodeActivators() {
        loadModuleActivators();
        return activators;
    }

    @Override
    public void nodeStarted(Node node) {
        for(NodeActivator activator : activators) {
            activator.nodeStarted(node);
        }
    }

    @Override
    public void nodeStopped(Node node) {
        for(NodeActivator activator : activators) {
            activator.nodeStopped(node);
        }
    }



    /**
     * Dynamically load node activators declared under META-INF/services
     */
    private synchronized void loadModuleActivators() {
        if (loadedActivators)
            return;

        // Get the activator service declarations
        Collection<ServiceDeclaration> activatorDeclarations;
        try {
            // Load the module activators by ranking
            activatorDeclarations = registry.getServiceDiscovery().getServiceDeclarations(NodeActivator.class.getName(), true);
        } catch (IOException e) {
            throw new IllegalStateException(e);
        }

        // Load and instantiate module activators
        for (ServiceDeclaration activatorDeclaration : activatorDeclarations) {
            if (logger.isLoggable(Level.FINE)) {
                logger.fine("Loading " + activatorDeclaration.getClassName());
            }
            NodeActivator activator = null;
            try {
                Class<NodeActivator> activatorClass = (Class<NodeActivator>)activatorDeclaration.loadClass();
                try {
                    activator = ServiceHelper.newInstance(activatorClass, ExtensionPointRegistry.class, registry);
                } catch (NoSuchMethodException e) {
                    try {
                        activator =
                            ServiceHelper.newInstance(activatorClass,
                                          new Class<?>[] {ExtensionPointRegistry.class, Map.class},
                                          registry,
                                          activatorDeclaration.getAttributes());

                    } catch (NoSuchMethodException e1) {
                        activator = ServiceHelper.newInstance(activatorClass);

                    }
                }
            } catch (Throwable e) {
                String optional = activatorDeclaration.getAttributes().get("optional");
                if ("true".equalsIgnoreCase(optional)) {
                    // If the optional flag is true, just log the error
                    logger.log(Level.SEVERE, e.getMessage(), e);
                    continue;
                } else {
                    throw new IllegalArgumentException(e);
                }
            }
            addNodeActivator(activator);
        }

        loadedActivators = true;
    }
}