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copied!<p>Try this:</p> <ol> <li>Create a <a href="http://docs.oracle.com/javaee/6/api/javax/servlet/Filter.html" rel="nofollow">servlet Filter</a>. </li> <li>Make it implement <a href="http://docs.oracle.com/javase/1.5.0/docs/api/javax/management/DynamicMBean.html" rel="nofollow">DynamicMBean</a>. Register the bean in the Filter's <a href="http://docs.oracle.com/javaee/6/api/javax/servlet/Filter.html#init%28javax.servlet.FilterConfig%29" rel="nofollow">init</a> method (and unregister it in the <a href="http://docs.oracle.com/javaee/6/api/javax/servlet/Filter.html#destroy%28%29" rel="nofollow">destroy</a> method)</li> <li>Define a <a href="http://docs.oracle.com/javase/6/docs/api/java/util/Collections.html#synchronizedMap%28java.util.Map%29" rel="nofollow">synchronized</a> <a href="http://docs.oracle.com/javase/6/docs/api/java/util/WeakHashMap.html" rel="nofollow">WeakHashMap</a> field.</li> <li>In the filter's <a href="http://docs.oracle.com/javaee/6/api/javax/servlet/Filter.html#doFilter%28javax.servlet.ServletRequest,%20javax.servlet.ServletResponse,%20javax.servlet.FilterChain%29" rel="nofollow">doFilter</a> method, capture the URI of the request <em>before</em> the <a href="http://docs.oracle.com/javaee/6/api/javax/servlet/FilterChain.html" rel="nofollow">FilterChain</a>'s <a href="http://docs.oracle.com/javaee/6/api/javax/servlet/FilterChain.html#doFilter%28javax.servlet.ServletRequest,%20javax.servlet.ServletResponse%29" rel="nofollow">doFilter</a> method is called. Insert the thread and the request URI into the WeakHashMap.</li> <li>Call the chain.</li> <li>In a finally block, insert the current thread and some arbitrary constant like <strong>NO REQUEST</strong> into the WeakHashMap.</li> <li>Implement the DynamicMBean so that the <a href="http://docs.oracle.com/javase/6/docs/api/javax/management/MBeanInfo.html" rel="nofollow">MBeanInfo</a> presents one <a href="http://docs.oracle.com/javase/6/docs/api/javax/management/MBeanAttributeInfo.html" rel="nofollow">MBeanAttributeInfo</a> per thread in the WeakHashMap. Make the attribute names the names of the threads and the type a <strong>URI</strong> (or a <strong>String</strong>).</li> <li>Implement the DynamicMBean so that the <a href="http://docs.oracle.com/javase/6/docs/api/javax/management/DynamicMBean.html#getAttribute%28java.lang.String%29" rel="nofollow">getAttribute</a> method returns the URI of the thread that corresponds to the requested attribute name.</li> <li>Configure the filter so that it is called for all URI ranges you want to track.</li> </ol> <p>When you view the attributes of the MBean, you will see the URI (or <strong>NO REQUEST</strong>) for each thread that is still active in the JVM that has processed at least one request. When a thread terminates (and perhaps after a few GC cycles), the WeakHashMap entry will be removed.</p> <p>It looks a bit arduous now that I read it, but it should be pretty straightforward.</p> <p>//Nicholas</p>

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