| [66] | 1 | <html><head><META http-equiv="Content-Type" content="text/html; charset=iso-8859-1"><title>Apache Tomcat Configuration Reference - The Engine Container</title><meta value="Craig R. McClanahan" name="author"><meta value="craigmcc@apache.org" name="email"></head><body vlink="#525D76" alink="#525D76" link="#525D76" text="#000000" bgcolor="#ffffff"><table cellspacing="0" width="100%" border="0"><!--PAGE HEADER--><tr><td><!--PROJECT LOGO--><a href="http://tomcat.apache.org/"><img border="0" alt=" | 
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|  | 2 | The Apache Tomcat Servlet/JSP Container | 
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|  | 3 | " align="right" src="../images/tomcat.gif"></a></td><td><font face="arial,helvetica,sanserif"><h1>Apache Tomcat 6.0</h1></font></td><td><!--APACHE LOGO--><a href="http://www.apache.org/"><img border="0" alt="Apache Logo" align="right" src="../images/asf-logo.gif"></a></td></tr></table><table cellspacing="4" width="100%" border="0"><!--HEADER SEPARATOR--><tr><td colspan="2"><hr size="1" noshade></td></tr><tr><!--LEFT SIDE NAVIGATION--><td nowrap="true" valign="top" width="20%"><p><strong>Links</strong></p><ul><li><a href="../index.html">Docs Home</a></li><li><a href="index.html">Config Ref. Home</a></li></ul><p><strong>Top Level Elements</strong></p><ul><li><a href="server.html">Server</a></li><li><a href="service.html">Service</a></li></ul><p><strong>Executors</strong></p><ul><li><a href="executor.html">Executor</a></li></ul><p><strong>Connectors</strong></p><ul><li><a href="http.html">HTTP</a></li><li><a href="ajp.html">AJP</a></li></ul><p><strong>Containers</strong></p><ul><li><a href="context.html">Context</a></li><li><a href="engine.html">Engine</a></li><li><a href="host.html">Host</a></li><li><a href="cluster.html">Cluster</a></li></ul><p><strong>Nested Components</strong></p><ul><li><a href="globalresources.html">Global Resources</a></li><li><a href="loader.html">Loader</a></li><li><a href="manager.html">Manager</a></li><li><a href="realm.html">Realm</a></li><li><a href="resources.html">Resources</a></li><li><a href="valve.html">Valve</a></li></ul><p><strong>Cluster Elements</strong></p><ul><li><a href="cluster.html">Cluster</a></li><li><a href="cluster-manager.html">Manager</a></li><li><a href="cluster-channel.html">Channel</a></li><li><a href="cluster-membership.html">Channel/Membership</a></li><li><a href="cluster-sender.html">Channel/Sender</a></li><li><a href="cluster-receiver.html">Channel/Receiver</a></li><li><a href="cluster-interceptor.html">Channel/Interceptor</a></li><li><a href="cluster-valve.html">Valve</a></li><li><a href="cluster-deployer.html">Deployer</a></li><li><a href="cluster-listener.html">ClusterListener</a></li></ul><p><strong>Global Settings</strong></p><ul><li><a href="systemprops.html">System properties</a></li></ul></td><!--RIGHT SIDE MAIN BODY--><td align="left" valign="top" width="80%"><table cellspacing="4" width="100%" border="0"><tr><td valign="top" align="left"><h1>Apache Tomcat Configuration Reference</h1><h2>The Engine Container</h2></td><td nowrap="true" valign="top" align="right"><small><a href="printer/engine.html"><img alt="Printer Friendly Version" border="0" src="../images/printer.gif"><br>print-friendly<br>version | 
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|  | 4 | </a></small></td></tr></table><table cellpadding="2" cellspacing="0" border="0"><tr><td bgcolor="#525D76"><font face="arial,helvetica.sanserif" color="#ffffff"><a name="Introduction"><strong>Introduction</strong></a></font></td></tr><tr><td><blockquote> | 
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|  | 5 |  | 
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|  | 6 | <p>The <strong>Engine</strong> element represents the entire request | 
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|  | 7 | processing machinery associated with a particular Catalina | 
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|  | 8 | <a href="service.html">Service</a>.  It receives and processes | 
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|  | 9 | <em>all</em> requests from one or more <strong>Connectors</strong>, | 
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|  | 10 | and returns the completed response to the Connector for ultimate | 
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|  | 11 | transmission back to the client.</p> | 
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|  | 12 |  | 
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|  | 13 | <p>Exactly one <strong>Engine</strong> element MUST be nested inside | 
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|  | 14 | a <a href="service.html">Service</a> element, following all of the | 
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|  | 15 | corresponding Connector elements associated with this Service.</p> | 
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|  | 16 |  | 
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|  | 17 | </blockquote></td></tr></table><table cellpadding="2" cellspacing="0" border="0"><tr><td bgcolor="#525D76"><font face="arial,helvetica.sanserif" color="#ffffff"><a name="Attributes"><strong>Attributes</strong></a></font></td></tr><tr><td><blockquote> | 
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|  | 18 |  | 
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|  | 19 | <table cellpadding="2" cellspacing="0" border="0"><tr><td bgcolor="#828DA6"><font face="arial,helvetica.sanserif" color="#ffffff"><a name="Common Attributes"><strong>Common Attributes</strong></a></font></td></tr><tr><td><blockquote> | 
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|  | 20 |  | 
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|  | 21 | <p>All implementations of <strong>Engine</strong> | 
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|  | 22 | support the following attributes:</p> | 
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|  | 23 |  | 
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|  | 24 | <table cellpadding="5" border="1"><tr><th bgcolor="#023264" width="15%"><font color="#ffffff">Attribute</font></th><th bgcolor="#023264" width="85%"><font color="#ffffff">Description</font></th></tr><tr><td valign="center" align="left"><code>backgroundProcessorDelay</code></td><td valign="center" align="left"> | 
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|  | 25 | <p>This value represents the delay in seconds between the | 
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|  | 26 | invocation of the backgroundProcess method on this engine and | 
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|  | 27 | its child containers, including all hosts and contexts. | 
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|  | 28 | Child containers will not be invoked if their delay value is not | 
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|  | 29 | negative (which would mean they are using their own processing | 
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|  | 30 | thread). Setting this to a positive value will cause | 
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|  | 31 | a thread to be spawn. After waiting the specified amount of time, | 
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|  | 32 | the thread will invoke the backgroundProcess method on this engine | 
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|  | 33 | and all its child containers. If not specified, the default value for | 
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|  | 34 | this attribute is 10, which represent a 10 seconds delay.</p> | 
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|  | 35 | </td></tr><tr><td valign="center" align="left"><code>className</code></td><td valign="center" align="left"> | 
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|  | 36 | <p>Java class name of the implementation to use.  This class must | 
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|  | 37 | implement the <code>org.apache.catalina.Engine</code> interface. | 
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|  | 38 | If not specified, the standard value (defined below) will be used.</p> | 
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|  | 39 | </td></tr><tr><td valign="center" align="left"><strong><code>defaultHost</code></strong></td><td valign="center" align="left"> | 
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|  | 40 | <p>The default host name, which identifies the | 
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|  | 41 | <a href="host.html">Host</a> that will process requests directed | 
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|  | 42 | to host names on this server, but which are not configured in | 
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|  | 43 | this configuration file.  This name MUST match the <code>name</code> | 
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|  | 44 | attributes of one of the <a href="host.html">Host</a> elements | 
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|  | 45 | nested immediately inside.</p> | 
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|  | 46 | </td></tr><tr><td valign="center" align="left"><code>jvmRoute</code></td><td valign="center" align="left"> | 
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|  | 47 | <p>Identifier which must be used in load balancing scenarios to enable | 
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|  | 48 | session affinity. The identifier, which must be unique across all | 
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|  | 49 | Tomcat 6 servers which participate in the cluster, will be appended to | 
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|  | 50 | the generated session identifier, therefore allowing the front end | 
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|  | 51 | proxy to always forward a particular session to the same Tomcat 6 | 
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|  | 52 | instance.</p> | 
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|  | 53 | </td></tr><tr><td valign="center" align="left"><strong><code>name</code></strong></td><td valign="center" align="left"> | 
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|  | 54 | <p>Logical name of this Engine, used in log and error messages. <em>When | 
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|  | 55 | using muliple <a href="service.html">Service</a> elements in the same | 
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|  | 56 | <a href="server.html">Server</a>, each Engine MUST be assigned a unique | 
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|  | 57 | name.</em></p> | 
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|  | 58 | </td></tr></table> | 
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|  | 59 |  | 
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|  | 60 | </blockquote></td></tr></table> | 
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|  | 61 |  | 
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|  | 62 |  | 
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|  | 63 | <table cellpadding="2" cellspacing="0" border="0"><tr><td bgcolor="#828DA6"><font face="arial,helvetica.sanserif" color="#ffffff"><a name="Standard Implementation"><strong>Standard Implementation</strong></a></font></td></tr><tr><td><blockquote> | 
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|  | 64 |  | 
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|  | 65 | <p>The standard implementation of <strong>Engine</strong> is | 
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|  | 66 | <strong>org.apache.catalina.core.StandardEngine</strong>. | 
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|  | 67 | It supports the following additional attributes (in addition to the | 
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|  | 68 | common attributes listed above):</p> | 
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|  | 69 |  | 
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|  | 70 | <table cellpadding="5" border="1"><tr><th bgcolor="#023264" width="15%"><font color="#ffffff">Attribute</font></th><th bgcolor="#023264" width="85%"><font color="#ffffff">Description</font></th></tr></table> | 
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|  | 71 |  | 
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|  | 72 | </blockquote></td></tr></table> | 
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|  | 73 |  | 
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|  | 74 |  | 
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|  | 75 | </blockquote></td></tr></table><table cellpadding="2" cellspacing="0" border="0"><tr><td bgcolor="#525D76"><font face="arial,helvetica.sanserif" color="#ffffff"><a name="Nested Components"><strong>Nested Components</strong></a></font></td></tr><tr><td><blockquote> | 
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|  | 76 |  | 
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|  | 77 | <p>You can nest one or more <a href="host.html">Host</a> elements inside | 
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|  | 78 | this <strong>Engine</strong> element, each representing a different virtual | 
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|  | 79 | host associated with this server.  At least one <a href="host.html">Host</a> | 
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|  | 80 | is required, and one of the nested <a href="host.html">Hosts</a> MUST | 
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|  | 81 | have a name that matches the name specified for the | 
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|  | 82 | <code>defaultHost</code> attribute, listed above.</p> | 
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|  | 83 |  | 
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|  | 84 | <p>You can optional nest a <a href="defaultcontext.html">DefaultContext</a> | 
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|  | 85 | element inside this <strong>Engine</strong> element, to define the default | 
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|  | 86 | characteristics of web applications that are automatically deployed.</p> | 
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|  | 87 |  | 
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|  | 88 | <p>You can nest at most one instance of the following utility components | 
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|  | 89 | by nesting a corresponding element inside your <strong>Engine</strong> | 
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|  | 90 | element:</p> | 
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|  | 91 | <ul> | 
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|  | 92 | <li><a href="realm.html"><strong>Realm</strong></a> - | 
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|  | 93 | Configure a realm that will allow its | 
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|  | 94 | database of users, and their associated roles, to be shared across all | 
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|  | 95 | <a href="host.html">Hosts</a> and <a href="context.html">Contexts</a> | 
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|  | 96 | nested inside this Engine, unless overridden by a | 
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|  | 97 | <a href="realm.html">Realm</a> configuration at a lower level.</li> | 
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|  | 98 | </ul> | 
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|  | 99 |  | 
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|  | 100 | </blockquote></td></tr></table><table cellpadding="2" cellspacing="0" border="0"><tr><td bgcolor="#525D76"><font face="arial,helvetica.sanserif" color="#ffffff"><a name="Special Features"><strong>Special Features</strong></a></font></td></tr><tr><td><blockquote> | 
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|  | 101 |  | 
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|  | 102 |  | 
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|  | 103 | <table cellpadding="2" cellspacing="0" border="0"><tr><td bgcolor="#828DA6"><font face="arial,helvetica.sanserif" color="#ffffff"><a name="Logging"><strong>Logging</strong></a></font></td></tr><tr><td><blockquote> | 
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|  | 104 |  | 
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|  | 105 | <p>An engine is associated with the | 
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|  | 106 | <code>org.apache.catalina.core.ContainerBase.[enginename]</code> | 
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|  | 107 | log category.  Note that the brackets are actually part of the name, | 
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|  | 108 | don't omit them.</p> | 
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|  | 109 |  | 
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|  | 110 | </blockquote></td></tr></table> | 
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|  | 111 |  | 
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|  | 112 |  | 
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|  | 113 | <table cellpadding="2" cellspacing="0" border="0"><tr><td bgcolor="#828DA6"><font face="arial,helvetica.sanserif" color="#ffffff"><a name="Access Logs"><strong>Access Logs</strong></a></font></td></tr><tr><td><blockquote> | 
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|  | 114 |  | 
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|  | 115 | <p>When you run a web server, one of the output files normally generated | 
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|  | 116 | is an <em>access log</em>, which generates one line of information for | 
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|  | 117 | each request processed by the server, in a standard format.  Catalina | 
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|  | 118 | includes an optional <a href="valve.html">Valve</a> implementation that | 
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|  | 119 | can create access logs in the same standard format created by web servers, | 
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|  | 120 | or in any number of custom formats.</p> | 
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|  | 121 |  | 
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|  | 122 | <p>You can ask Catalina to create an access log for all requests | 
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|  | 123 | processed by an <a href="engine.html">Engine</a>, | 
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|  | 124 | <a href="host.html">Host</a>, or <a href="context.html">Context</a> | 
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|  | 125 | by nesting a <a href="valve.html">Valve</a> element like this:</p> | 
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|  | 126 |  | 
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|  | 127 | <div align="left"><table border="0" cellpadding="0" cellspacing="4"><tr><td height="1" width="1" bgcolor="#023264"><img border="0" hspace="0" vspace="0" height="1" width="1" src="../images/void.gif"></td><td height="1" bgcolor="#023264"><img border="0" hspace="0" vspace="0" height="1" width="1" src="../images/void.gif"></td><td height="1" width="1" bgcolor="#023264"><img border="0" hspace="0" vspace="0" height="1" width="1" src="../images/void.gif"></td></tr><tr><td width="1" bgcolor="#023264"><img border="0" hspace="0" vspace="0" height="1" width="1" src="../images/void.gif"></td><td height="1" bgcolor="#ffffff"><pre> | 
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|  | 128 | <Engine name="Standalone" ...> | 
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|  | 129 | ... | 
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|  | 130 | <Valve className="org.apache.catalina.valves.AccessLogValve" | 
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|  | 131 | prefix="catalina_access_log." suffix=".txt" | 
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|  | 132 | pattern="common"/> | 
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|  | 133 | ... | 
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|  | 134 | </Engine> | 
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|  | 135 | </pre></td><td width="1" bgcolor="#023264"><img border="0" hspace="0" vspace="0" height="1" width="1" src="../images/void.gif"></td></tr><tr><td height="1" width="1" bgcolor="#023264"><img border="0" hspace="0" vspace="0" height="1" width="1" src="../images/void.gif"></td><td height="1" bgcolor="#023264"><img border="0" hspace="0" vspace="0" height="1" width="1" src="../images/void.gif"></td><td height="1" width="1" bgcolor="#023264"><img border="0" hspace="0" vspace="0" height="1" width="1" src="../images/void.gif"></td></tr></table></div> | 
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|  | 136 |  | 
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|  | 137 | <p>See <a href="valve.html#Access Log Valve">Access Log Valve</a> | 
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|  | 138 | for more information on the configuration attributes that are | 
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|  | 139 | supported.</p> | 
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|  | 140 |  | 
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|  | 141 | </blockquote></td></tr></table> | 
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|  | 142 |  | 
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|  | 143 |  | 
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|  | 144 | <table cellpadding="2" cellspacing="0" border="0"><tr><td bgcolor="#828DA6"><font face="arial,helvetica.sanserif" color="#ffffff"><a name="Lifecycle Listeners"><strong>Lifecycle Listeners</strong></a></font></td></tr><tr><td><blockquote> | 
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|  | 145 |  | 
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|  | 146 | <p>If you have implemented a Java object that needs to know when this | 
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|  | 147 | <strong>Engine</strong> is started or stopped, you can declare it by | 
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|  | 148 | nesting a <strong>Listener</strong> element inside this element.  The | 
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|  | 149 | class name you specify must implement the | 
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|  | 150 | <code>org.apache.catalina.LifecycleListener</code> interface, and | 
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|  | 151 | it will be notified about the occurrence of the coresponding | 
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|  | 152 | lifecycle events.  Configuration of such a listener looks like this:</p> | 
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|  | 153 |  | 
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|  | 154 | <div align="left"><table border="0" cellpadding="0" cellspacing="4"><tr><td height="1" width="1" bgcolor="#023264"><img border="0" hspace="0" vspace="0" height="1" width="1" src="../images/void.gif"></td><td height="1" bgcolor="#023264"><img border="0" hspace="0" vspace="0" height="1" width="1" src="../images/void.gif"></td><td height="1" width="1" bgcolor="#023264"><img border="0" hspace="0" vspace="0" height="1" width="1" src="../images/void.gif"></td></tr><tr><td width="1" bgcolor="#023264"><img border="0" hspace="0" vspace="0" height="1" width="1" src="../images/void.gif"></td><td height="1" bgcolor="#ffffff"><pre> | 
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|  | 155 | <Engine name="Standalone" ...> | 
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|  | 156 | ... | 
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|  | 157 | <Listener className="com.mycompany.mypackage.MyListener" ... > | 
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|  | 158 | ... | 
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|  | 159 | </Engine> | 
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|  | 160 | </pre></td><td width="1" bgcolor="#023264"><img border="0" hspace="0" vspace="0" height="1" width="1" src="../images/void.gif"></td></tr><tr><td height="1" width="1" bgcolor="#023264"><img border="0" hspace="0" vspace="0" height="1" width="1" src="../images/void.gif"></td><td height="1" bgcolor="#023264"><img border="0" hspace="0" vspace="0" height="1" width="1" src="../images/void.gif"></td><td height="1" width="1" bgcolor="#023264"><img border="0" hspace="0" vspace="0" height="1" width="1" src="../images/void.gif"></td></tr></table></div> | 
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|  | 161 |  | 
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|  | 162 | <p>Note that a Listener can have any number of additional properties | 
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|  | 163 | that may be configured from this element.  Attribute names are matched | 
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|  | 164 | to corresponding JavaBean property names using the standard property | 
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|  | 165 | method naming patterns.</p> | 
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|  | 166 |  | 
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|  | 167 | </blockquote></td></tr></table> | 
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|  | 168 |  | 
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|  | 169 |  | 
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|  | 170 | <table cellpadding="2" cellspacing="0" border="0"><tr><td bgcolor="#828DA6"><font face="arial,helvetica.sanserif" color="#ffffff"><a name="Request Filters"><strong>Request Filters</strong></a></font></td></tr><tr><td><blockquote> | 
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|  | 171 |  | 
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|  | 172 | <p>You can ask Catalina to check the IP address, or host name, on every | 
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|  | 173 | incoming request directed to the surrounding | 
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|  | 174 | <a href="engine.html">Engine</a>, <a href="host.html">Host</a>, or | 
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|  | 175 | <a href="context.html">Context</a> element.  The remote address or name | 
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|  | 176 | will be checked against a configured list of "accept" and/or "deny" | 
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|  | 177 | filters, which are defined using the Regular Expression syntax supported | 
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|  | 178 | by the <a href="http://jakarta.apache.org/regexp/">Jakarta Regexp</a> | 
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|  | 179 | regular expression library.  Requests that come from locations that are | 
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|  | 180 | not accepted will be rejected with an HTTP "Forbidden" error. | 
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|  | 181 | Example filter declarations:</p> | 
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|  | 182 |  | 
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|  | 183 | <div align="left"><table border="0" cellpadding="0" cellspacing="4"><tr><td height="1" width="1" bgcolor="#023264"><img border="0" hspace="0" vspace="0" height="1" width="1" src="../images/void.gif"></td><td height="1" bgcolor="#023264"><img border="0" hspace="0" vspace="0" height="1" width="1" src="../images/void.gif"></td><td height="1" width="1" bgcolor="#023264"><img border="0" hspace="0" vspace="0" height="1" width="1" src="../images/void.gif"></td></tr><tr><td width="1" bgcolor="#023264"><img border="0" hspace="0" vspace="0" height="1" width="1" src="../images/void.gif"></td><td height="1" bgcolor="#ffffff"><pre> | 
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|  | 184 | <Engine name="Standalone" ...> | 
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|  | 185 | ... | 
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|  | 186 | <Valve className="org.apache.catalina.valves.RemoteHostValve" | 
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|  | 187 | allow="*.mycompany.com,www.yourcompany.com"/> | 
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|  | 188 | <Valve className="org.apache.catalina.valves.RemoteAddrValve" | 
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|  | 189 | deny="192.168.1.*"/> | 
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|  | 190 | ... | 
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|  | 191 | </Engine> | 
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|  | 192 | </pre></td><td width="1" bgcolor="#023264"><img border="0" hspace="0" vspace="0" height="1" width="1" src="../images/void.gif"></td></tr><tr><td height="1" width="1" bgcolor="#023264"><img border="0" hspace="0" vspace="0" height="1" width="1" src="../images/void.gif"></td><td height="1" bgcolor="#023264"><img border="0" hspace="0" vspace="0" height="1" width="1" src="../images/void.gif"></td><td height="1" width="1" bgcolor="#023264"><img border="0" hspace="0" vspace="0" height="1" width="1" src="../images/void.gif"></td></tr></table></div> | 
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|  | 193 |  | 
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|  | 194 | <p>See <a href="valve.html#Remote Address Filter">Remote Address Filter</a> | 
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|  | 195 | and <a href="valve.html#Remote Host Filter">Remote Host Filter</a> for | 
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|  | 196 | more information about the configuration options that are supported.</p> | 
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|  | 197 |  | 
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|  | 198 | </blockquote></td></tr></table> | 
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|  | 199 |  | 
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|  | 200 |  | 
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|  | 201 | </blockquote></td></tr></table></td></tr><!--FOOTER SEPARATOR--><tr><td colspan="2"><hr size="1" noshade></td></tr><!--PAGE FOOTER--><tr><td colspan="2"><div align="center"><font size="-1" color="#525D76"><em> | 
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|  | 202 | Copyright © 1999-2008, Apache Software Foundation | 
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