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<pre><span class="sourceLineNo">001</span>/* <a name="line.1"></a>
<span class="sourceLineNo">002</span> * Licensed to the Apache Software Foundation (ASF) under one<a name="line.2"></a>
<span class="sourceLineNo">003</span> * or more contributor license agreements. See the NOTICE file<a name="line.3"></a>
<span class="sourceLineNo">004</span> * distributed with this work for additional information<a name="line.4"></a>
<span class="sourceLineNo">005</span> * regarding copyright ownership. The ASF licenses this file<a name="line.5"></a>
<span class="sourceLineNo">006</span> * to you under the Apache License, Version 2.0 (the<a name="line.6"></a>
<span class="sourceLineNo">007</span> * "License"); you may not use this file except in compliance<a name="line.7"></a>
<span class="sourceLineNo">008</span> * with the License. You may obtain a copy of the License at<a name="line.8"></a>
<span class="sourceLineNo">009</span> *<a name="line.9"></a>
<span class="sourceLineNo">010</span> * http://www.apache.org/licenses/LICENSE-2.0<a name="line.10"></a>
<span class="sourceLineNo">011</span> *<a name="line.11"></a>
<span class="sourceLineNo">012</span> * Unless required by applicable law or agreed to in writing,<a name="line.12"></a>
<span class="sourceLineNo">013</span> * software distributed under the License is distributed on an<a name="line.13"></a>
<span class="sourceLineNo">014</span> * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY<a name="line.14"></a>
<span class="sourceLineNo">015</span> * KIND, either express or implied. See the License for the<a name="line.15"></a>
<span class="sourceLineNo">016</span> * specific language governing permissions and limitations<a name="line.16"></a>
<span class="sourceLineNo">017</span> * under the License.<a name="line.17"></a>
<span class="sourceLineNo">018</span> */<a name="line.18"></a>
<span class="sourceLineNo">019</span>package org.apache.felix.ipojo;<a name="line.19"></a>
<span class="sourceLineNo">020</span><a name="line.20"></a>
<span class="sourceLineNo">021</span>import java.util.ArrayList;<a name="line.21"></a>
<span class="sourceLineNo">022</span>import java.util.HashMap;<a name="line.22"></a>
<span class="sourceLineNo">023</span>import java.util.Iterator;<a name="line.23"></a>
<span class="sourceLineNo">024</span>import java.util.List;<a name="line.24"></a>
<span class="sourceLineNo">025</span>import java.util.Map;<a name="line.25"></a>
<span class="sourceLineNo">026</span>import java.util.Set;<a name="line.26"></a>
<span class="sourceLineNo">027</span><a name="line.27"></a>
<span class="sourceLineNo">028</span>import org.osgi.framework.BundleContext;<a name="line.28"></a>
<span class="sourceLineNo">029</span>import org.osgi.framework.Constants;<a name="line.29"></a>
<span class="sourceLineNo">030</span>import org.osgi.framework.ServiceEvent;<a name="line.30"></a>
<span class="sourceLineNo">031</span>import org.osgi.framework.ServiceListener;<a name="line.31"></a>
<span class="sourceLineNo">032</span><a name="line.32"></a>
<span class="sourceLineNo">033</span>/**<a name="line.33"></a>
<span class="sourceLineNo">034</span> * iPOJO Internal event dispatcher.<a name="line.34"></a>
<span class="sourceLineNo">035</span> * This class provides an internal service event dispatcher in order to tackle the<a name="line.35"></a>
<span class="sourceLineNo">036</span> * event storm that can happen when starting large-scale applications.<a name="line.36"></a>
<span class="sourceLineNo">037</span> * @author &lt;a href="mailto:dev@felix.apache.org"&gt;Felix Project Team&lt;/a&gt;<a name="line.37"></a>
<span class="sourceLineNo">038</span> * @see org.osgi.framework.ServiceListener<a name="line.38"></a>
<span class="sourceLineNo">039</span> */<a name="line.39"></a>
<span class="sourceLineNo">040</span>public final class EventDispatcher implements ServiceListener {<a name="line.40"></a>
<span class="sourceLineNo">041</span> <a name="line.41"></a>
<span class="sourceLineNo">042</span> /**<a name="line.42"></a>
<span class="sourceLineNo">043</span> * The internal event dispatcher.<a name="line.43"></a>
<span class="sourceLineNo">044</span> * This dispatcher is a singleton.<a name="line.44"></a>
<span class="sourceLineNo">045</span> */<a name="line.45"></a>
<span class="sourceLineNo">046</span> private static EventDispatcher DISPATCHER;<a name="line.46"></a>
<span class="sourceLineNo">047</span> <a name="line.47"></a>
<span class="sourceLineNo">048</span> /**<a name="line.48"></a>
<span class="sourceLineNo">049</span> * The list of listeners.<a name="line.49"></a>
<span class="sourceLineNo">050</span> * Service interface -&gt; List of {@link ServiceListener}<a name="line.50"></a>
<span class="sourceLineNo">051</span> */<a name="line.51"></a>
<span class="sourceLineNo">052</span> private Map m_listeners;<a name="line.52"></a>
<span class="sourceLineNo">053</span> /**<a name="line.53"></a>
<span class="sourceLineNo">054</span> * The global bundle context.<a name="line.54"></a>
<span class="sourceLineNo">055</span> * This is the bundle context from iPOJO.<a name="line.55"></a>
<span class="sourceLineNo">056</span> */<a name="line.56"></a>
<span class="sourceLineNo">057</span> private BundleContext m_context;<a name="line.57"></a>
<span class="sourceLineNo">058</span> <a name="line.58"></a>
<span class="sourceLineNo">059</span> /**<a name="line.59"></a>
<span class="sourceLineNo">060</span> * Creates the EventDispatcher.<a name="line.60"></a>
<span class="sourceLineNo">061</span> * @param bc the bundle context used to register and unregister<a name="line.61"></a>
<span class="sourceLineNo">062</span> * {@link ServiceListener}.<a name="line.62"></a>
<span class="sourceLineNo">063</span> */<a name="line.63"></a>
<span class="sourceLineNo">064</span> private EventDispatcher(BundleContext bc) {<a name="line.64"></a>
<span class="sourceLineNo">065</span> m_context = bc;<a name="line.65"></a>
<span class="sourceLineNo">066</span> m_listeners = new HashMap();<a name="line.66"></a>
<span class="sourceLineNo">067</span> // Only one thread can call the start method.<a name="line.67"></a>
<span class="sourceLineNo">068</span> m_context.addServiceListener(this);<a name="line.68"></a>
<span class="sourceLineNo">069</span> }<a name="line.69"></a>
<span class="sourceLineNo">070</span> <a name="line.70"></a>
<span class="sourceLineNo">071</span> /**<a name="line.71"></a>
<span class="sourceLineNo">072</span> * Creates the internal event<a name="line.72"></a>
<span class="sourceLineNo">073</span> * dispatcher.<a name="line.73"></a>
<span class="sourceLineNo">074</span> * @param bc the iPOJO bundle context to send to the <a name="line.74"></a>
<span class="sourceLineNo">075</span> * internal event dispatcher.<a name="line.75"></a>
<span class="sourceLineNo">076</span> */<a name="line.76"></a>
<span class="sourceLineNo">077</span> public static void create(BundleContext bc) {<a name="line.77"></a>
<span class="sourceLineNo">078</span> DISPATCHER = new EventDispatcher(bc);<a name="line.78"></a>
<span class="sourceLineNo">079</span> }<a name="line.79"></a>
<span class="sourceLineNo">080</span> <a name="line.80"></a>
<span class="sourceLineNo">081</span> /**<a name="line.81"></a>
<span class="sourceLineNo">082</span> * Stops and delete the internal event dispatcher.<a name="line.82"></a>
<span class="sourceLineNo">083</span> * This method must be call only<a name="line.83"></a>
<span class="sourceLineNo">084</span> * if iPOJO is stopping.<a name="line.84"></a>
<span class="sourceLineNo">085</span> */<a name="line.85"></a>
<span class="sourceLineNo">086</span> public static void dispose() {<a name="line.86"></a>
<span class="sourceLineNo">087</span> DISPATCHER.stop();<a name="line.87"></a>
<span class="sourceLineNo">088</span> DISPATCHER = null;<a name="line.88"></a>
<span class="sourceLineNo">089</span> }<a name="line.89"></a>
<span class="sourceLineNo">090</span> <a name="line.90"></a>
<span class="sourceLineNo">091</span> <a name="line.91"></a>
<span class="sourceLineNo">092</span> /**<a name="line.92"></a>
<span class="sourceLineNo">093</span> * Gets the iPOJO event dispatcher.<a name="line.93"></a>
<span class="sourceLineNo">094</span> * @return the event dispatcher or<a name="line.94"></a>
<span class="sourceLineNo">095</span> * &lt;code&gt;null&lt;/code&gt; if not created.<a name="line.95"></a>
<span class="sourceLineNo">096</span> */<a name="line.96"></a>
<span class="sourceLineNo">097</span> public static EventDispatcher getDispatcher() {<a name="line.97"></a>
<span class="sourceLineNo">098</span> return DISPATCHER;<a name="line.98"></a>
<span class="sourceLineNo">099</span> }<a name="line.99"></a>
<span class="sourceLineNo">100</span> <a name="line.100"></a>
<span class="sourceLineNo">101</span> <a name="line.101"></a>
<span class="sourceLineNo">102</span> /**<a name="line.102"></a>
<span class="sourceLineNo">103</span> * Stops the event dispatcher.<a name="line.103"></a>
<span class="sourceLineNo">104</span> * This method unregisters the {@link ServiceListener}.<a name="line.104"></a>
<span class="sourceLineNo">105</span> * This methods must be called only when the iPOJO bundle<a name="line.105"></a>
<span class="sourceLineNo">106</span> * stops.<a name="line.106"></a>
<span class="sourceLineNo">107</span> */<a name="line.107"></a>
<span class="sourceLineNo">108</span> private void stop() {<a name="line.108"></a>
<span class="sourceLineNo">109</span> synchronized (this) {<a name="line.109"></a>
<span class="sourceLineNo">110</span> m_context.removeServiceListener(this);<a name="line.110"></a>
<span class="sourceLineNo">111</span> m_listeners.clear();<a name="line.111"></a>
<span class="sourceLineNo">112</span> }<a name="line.112"></a>
<span class="sourceLineNo">113</span> }<a name="line.113"></a>
<span class="sourceLineNo">114</span><a name="line.114"></a>
<span class="sourceLineNo">115</span> /**<a name="line.115"></a>
<span class="sourceLineNo">116</span> * Method called when a {@link ServiceEvent} is<a name="line.116"></a>
<span class="sourceLineNo">117</span> * fired by the OSGi framework. <a name="line.117"></a>
<span class="sourceLineNo">118</span> * According to the event, this method dispatches<a name="line.118"></a>
<span class="sourceLineNo">119</span> * to interested registered listers from<a name="line.119"></a>
<span class="sourceLineNo">120</span> * the {@link EventDispatcher#m_listeners} map.<a name="line.120"></a>
<span class="sourceLineNo">121</span> * @param event the service event<a name="line.121"></a>
<span class="sourceLineNo">122</span> * @see org.osgi.framework.ServiceListener#serviceChanged(org.osgi.framework.ServiceEvent)<a name="line.122"></a>
<span class="sourceLineNo">123</span> */<a name="line.123"></a>
<span class="sourceLineNo">124</span> public void serviceChanged(ServiceEvent event) {<a name="line.124"></a>
<span class="sourceLineNo">125</span> String[] itfs = (String[]) event.getServiceReference().getProperty(Constants.OBJECTCLASS);<a name="line.125"></a>
<span class="sourceLineNo">126</span> for (int s = 0; s &lt; itfs.length; s++) {<a name="line.126"></a>
<span class="sourceLineNo">127</span> List list;<a name="line.127"></a>
<span class="sourceLineNo">128</span> synchronized (this) {<a name="line.128"></a>
<span class="sourceLineNo">129</span> List stored = (List) m_listeners.get(itfs[s]);<a name="line.129"></a>
<span class="sourceLineNo">130</span> if (stored == null) { <a name="line.130"></a>
<span class="sourceLineNo">131</span> return; // Nothing to do<a name="line.131"></a>
<span class="sourceLineNo">132</span> }<a name="line.132"></a>
<span class="sourceLineNo">133</span> // Creates a new list (stack confinement)<a name="line.133"></a>
<span class="sourceLineNo">134</span> list = new ArrayList(stored);<a name="line.134"></a>
<span class="sourceLineNo">135</span> }<a name="line.135"></a>
<span class="sourceLineNo">136</span> for (int i = 0; i &lt; list.size(); i++) {<a name="line.136"></a>
<span class="sourceLineNo">137</span> ((ServiceListener) list.get(i)).serviceChanged(event);<a name="line.137"></a>
<span class="sourceLineNo">138</span> }<a name="line.138"></a>
<span class="sourceLineNo">139</span> }<a name="line.139"></a>
<span class="sourceLineNo">140</span> }<a name="line.140"></a>
<span class="sourceLineNo">141</span> <a name="line.141"></a>
<span class="sourceLineNo">142</span> /**<a name="line.142"></a>
<span class="sourceLineNo">143</span> * Adds a new service listener to the {@link EventDispatcher#m_listeners}<a name="line.143"></a>
<span class="sourceLineNo">144</span> * map. This method specifies the listen service interface<a name="line.144"></a>
<span class="sourceLineNo">145</span> * @param itf the service interface<a name="line.145"></a>
<span class="sourceLineNo">146</span> * @param listener the service listener<a name="line.146"></a>
<span class="sourceLineNo">147</span> */<a name="line.147"></a>
<span class="sourceLineNo">148</span> public void addListener(String itf, ServiceListener listener) {<a name="line.148"></a>
<span class="sourceLineNo">149</span> synchronized (this) {<a name="line.149"></a>
<span class="sourceLineNo">150</span> List list = (List) m_listeners.get(itf);<a name="line.150"></a>
<span class="sourceLineNo">151</span> if (list == null) {<a name="line.151"></a>
<span class="sourceLineNo">152</span> list = new ArrayList(1);<a name="line.152"></a>
<span class="sourceLineNo">153</span> list.add(listener);<a name="line.153"></a>
<span class="sourceLineNo">154</span> m_listeners.put(itf, list);<a name="line.154"></a>
<span class="sourceLineNo">155</span> } else {<a name="line.155"></a>
<span class="sourceLineNo">156</span> list.add(listener);<a name="line.156"></a>
<span class="sourceLineNo">157</span> }<a name="line.157"></a>
<span class="sourceLineNo">158</span> }<a name="line.158"></a>
<span class="sourceLineNo">159</span> }<a name="line.159"></a>
<span class="sourceLineNo">160</span> <a name="line.160"></a>
<span class="sourceLineNo">161</span> /**<a name="line.161"></a>
<span class="sourceLineNo">162</span> * Removes a service listener.<a name="line.162"></a>
<span class="sourceLineNo">163</span> * @param listener the service listener to remove<a name="line.163"></a>
<span class="sourceLineNo">164</span> * @return &lt;code&gt;true&lt;/code&gt; if the listener is <a name="line.164"></a>
<span class="sourceLineNo">165</span> * successfully removed.<a name="line.165"></a>
<span class="sourceLineNo">166</span> */<a name="line.166"></a>
<span class="sourceLineNo">167</span> public boolean removeListener(ServiceListener listener) {<a name="line.167"></a>
<span class="sourceLineNo">168</span> boolean removed = false;<a name="line.168"></a>
<span class="sourceLineNo">169</span> synchronized (this) {<a name="line.169"></a>
<span class="sourceLineNo">170</span> Set keys = m_listeners.keySet();<a name="line.170"></a>
<span class="sourceLineNo">171</span> Iterator it = keys.iterator();<a name="line.171"></a>
<span class="sourceLineNo">172</span> while (it.hasNext()) {<a name="line.172"></a>
<span class="sourceLineNo">173</span> String itf = (String) it.next();<a name="line.173"></a>
<span class="sourceLineNo">174</span> List list = (List) m_listeners.get(itf);<a name="line.174"></a>
<span class="sourceLineNo">175</span> removed = removed || list.remove(listener);<a name="line.175"></a>
<span class="sourceLineNo">176</span> }<a name="line.176"></a>
<span class="sourceLineNo">177</span> }<a name="line.177"></a>
<span class="sourceLineNo">178</span> return removed;<a name="line.178"></a>
<span class="sourceLineNo">179</span> }<a name="line.179"></a>
<span class="sourceLineNo">180</span><a name="line.180"></a>
<span class="sourceLineNo">181</span>}<a name="line.181"></a>
</pre>
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