| [66] | 1 | <html><head><META http-equiv="Content-Type" content="text/html; charset=iso-8859-1"><title>Catalina Functional Specifications - Default Servlet</title><meta value="Craig 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 | Catalina Functional Specifications | 
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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">Functional Specs</a></li></ul><p><strong>Administrative Apps</strong></p><ul><li><a href="fs-admin-apps.html">Overall Requirements</a></li><li><a href="mbean-names.html">Tomcat MBean Names</a></li><li><a href="fs-admin-objects.html">Administered Objects</a></li><li><a href="fs-admin-opers.html">Supported Operations</a></li></ul><p><strong>Internal Servlets</strong></p><ul><li><a href="fs-default.html">Default Servlet</a></li><li><a href="fs-invoker.html">Invoker Servlet</a></li></ul><p><strong>Realm Implementations</strong></p><ul><li><a href="fs-jdbc-realm.html">JDBC Realm</a></li><li><a href="fs-jndi-realm.html">JNDI Realm</a></li><li><a href="fs-memory-realm.html">Memory Realm</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>Catalina Functional Specifications</h1><h2>Default Servlet</h2></td><td nowrap="true" valign="top" align="right"><small><a href="printer/fs-default.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="Overview"><strong>Overview</strong></a></font></td></tr><tr><td><blockquote> | 
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|  | 5 |  | 
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|  | 6 |  | 
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|  | 7 | <table cellpadding="2" cellspacing="0" border="0"><tr><td bgcolor="#828DA6"><font face="arial,helvetica.sanserif" color="#ffffff"><a name="Introduction"><strong>Introduction</strong></a></font></td></tr><tr><td><blockquote> | 
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|  | 8 |  | 
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|  | 9 | <p>The purpose of the <strong>Default Servlet</strong> is to serve | 
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|  | 10 | static resources of a web application in response to client requests. | 
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|  | 11 | As the name implies, it is generally configured as the "default" | 
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|  | 12 | servlet for a web application, by being mapped to a URL pattern "/".</p> | 
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|  | 13 |  | 
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|  | 14 | </blockquote></td></tr></table> | 
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|  | 15 |  | 
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|  | 16 |  | 
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|  | 17 | <table cellpadding="2" cellspacing="0" border="0"><tr><td bgcolor="#828DA6"><font face="arial,helvetica.sanserif" color="#ffffff"><a name="External Specifications"><strong>External Specifications</strong></a></font></td></tr><tr><td><blockquote> | 
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|  | 18 |  | 
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|  | 19 | <p>The following external specifications have provisions which | 
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|  | 20 | partially define the correct behavior of the default servlet:</p> | 
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|  | 21 | <ul> | 
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|  | 22 | <li><a href="http://java.sun.com/products/servlet/download.html"> | 
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|  | 23 | Servlet Specification</a> (Version 2.3 PFD2)</li> | 
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|  | 24 | <li><a href="http://www.rfc-editor.org/rfc/rfc2046.txt">Multipurpose | 
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|  | 25 | Internet Mail Extensions (MIME) Part Two: Media Types</a></li> | 
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|  | 26 | <li><a href="http://www.rfc-editor.org/rfc/rfc2616.txt">Hypertext | 
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|  | 27 | Transfer Protocol -- HTTP/1.1</a></li> | 
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|  | 28 | </ul> | 
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|  | 29 |  | 
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|  | 30 | </blockquote></td></tr></table> | 
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|  | 31 |  | 
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|  | 32 |  | 
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|  | 33 | <table cellpadding="2" cellspacing="0" border="0"><tr><td bgcolor="#828DA6"><font face="arial,helvetica.sanserif" color="#ffffff"><a name="Implementation Requirements"><strong>Implementation Requirements</strong></a></font></td></tr><tr><td><blockquote> | 
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|  | 34 |  | 
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|  | 35 | <p>The implementation of this functionality shall conform to the | 
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|  | 36 | following requirements:</p> | 
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|  | 37 | <ul> | 
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|  | 38 | <li>Must be implemented as a servlet.</li> | 
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|  | 39 | <li>Must support configurable parameters for debugging detail level, | 
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|  | 40 | input buffer size, output buffer size, whether or not to produce | 
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|  | 41 | directory listings when no welcome file is present, and whether or not | 
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|  | 42 | modifications are supported via DELETE and PUT.</li> | 
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|  | 43 | <li>Log debugging and operational messages (suitably internationalized) | 
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|  | 44 | via the <code>getServletContext().log()</code> method.</li> | 
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|  | 45 | </ul> | 
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|  | 46 |  | 
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|  | 47 | </blockquote></td></tr></table> | 
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|  | 48 |  | 
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|  | 49 |  | 
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|  | 50 | </blockquote></td></tr></table><table cellpadding="2" cellspacing="0" border="0"><tr><td bgcolor="#525D76"><font face="arial,helvetica.sanserif" color="#ffffff"><a name="Dependencies"><strong>Dependencies</strong></a></font></td></tr><tr><td><blockquote> | 
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|  | 51 |  | 
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|  | 52 |  | 
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|  | 53 | <table cellpadding="2" cellspacing="0" border="0"><tr><td bgcolor="#828DA6"><font face="arial,helvetica.sanserif" color="#ffffff"><a name="Environmental Dependencies"><strong>Environmental Dependencies</strong></a></font></td></tr><tr><td><blockquote> | 
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|  | 54 |  | 
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|  | 55 | <p>The following environmental dependencies must be met in order for | 
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|  | 56 | the default servlet to operate correctly:</p> | 
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|  | 57 | <ul> | 
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|  | 58 | <li>The default servlet must be registered in the application deployment | 
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|  | 59 | descriptor (or the default deployment descriptor in file | 
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|  | 60 | <code>$CATALINA_BASE/conf/web.xml</code>) using a "default servlet" | 
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|  | 61 | servlet mapping, signified by URL pattern "/".</li> | 
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|  | 62 | </ul> | 
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|  | 63 |  | 
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|  | 64 | </blockquote></td></tr></table> | 
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|  | 65 |  | 
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|  | 66 |  | 
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|  | 67 | <table cellpadding="2" cellspacing="0" border="0"><tr><td bgcolor="#828DA6"><font face="arial,helvetica.sanserif" color="#ffffff"><a name="Container Dependencies"><strong>Container Dependencies</strong></a></font></td></tr><tr><td><blockquote> | 
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|  | 68 |  | 
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|  | 69 | <p>Correct operation of the default servlet depends on the following | 
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|  | 70 | specific features of the surrounding container:</p> | 
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|  | 71 | <ul> | 
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|  | 72 | <li>The container shall provide a servlet context attribute that | 
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|  | 73 | lists the welcome file names that have been defined for this | 
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|  | 74 | web application.</li> | 
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|  | 75 | <li>The container shall provide a servlet context attribute that | 
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|  | 76 | contains a <code>javax.naming.directory.DirContext</code> | 
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|  | 77 | implementation representing the static resources of this | 
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|  | 78 | web application.</li> | 
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|  | 79 | </ul> | 
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|  | 80 |  | 
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|  | 81 | </blockquote></td></tr></table> | 
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|  | 82 |  | 
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|  | 83 |  | 
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|  | 84 | </blockquote></td></tr></table><table cellpadding="2" cellspacing="0" border="0"><tr><td bgcolor="#525D76"><font face="arial,helvetica.sanserif" color="#ffffff"><a name="Functionality"><strong>Functionality</strong></a></font></td></tr><tr><td><blockquote> | 
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|  | 85 |  | 
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|  | 86 |  | 
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|  | 87 | <table cellpadding="2" cellspacing="0" border="0"><tr><td bgcolor="#828DA6"><font face="arial,helvetica.sanserif" color="#ffffff"><a name="Initialization Functionality"><strong>Initialization Functionality</strong></a></font></td></tr><tr><td><blockquote> | 
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|  | 88 |  | 
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|  | 89 | <p>The following processing must be performed when the <code>init()</code> | 
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|  | 90 | method of the invoker servlet is called:</p> | 
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|  | 91 | <ul> | 
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|  | 92 | <li>Process and sanity check configuration parameters.</li> | 
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|  | 93 | </ul> | 
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|  | 94 |  | 
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|  | 95 | </blockquote></td></tr></table> | 
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|  | 96 |  | 
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|  | 97 |  | 
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|  | 98 | <table cellpadding="2" cellspacing="0" border="0"><tr><td bgcolor="#828DA6"><font face="arial,helvetica.sanserif" color="#ffffff"><a name="Per-Request Functionality"><strong>Per-Request Functionality</strong></a></font></td></tr><tr><td><blockquote> | 
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|  | 99 |  | 
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|  | 100 |  | 
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|  | 101 | <p>For all HTTP request methods, the resource path is determined from | 
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|  | 102 | the path information provided to this request, either as request attribute | 
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|  | 103 | <code>javax.servlet.include.path_info</code> (for a request dispatcher | 
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|  | 104 | access to a static resource) or by calling | 
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|  | 105 | <code>request.getPathInfo()</code> directly.</p> | 
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|  | 106 |  | 
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|  | 107 | <p>On each HTTP DELETE request processed by this servlet, the following | 
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|  | 108 | processing shall be performed:</p> | 
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|  | 109 | <ul> | 
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|  | 110 | <li>If modifications to the static resources are not allowed (set by a | 
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|  | 111 | configuration parameter), return HTTP status 403 (forbidden).</li> | 
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|  | 112 | <li>If an attempt is made to delete a resource from <code>/META-INF</code> | 
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|  | 113 | or <code>/WEB-INF</code>, return HTTP status 403 (forbidden).</li> | 
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|  | 114 | <li>If the requested resource does not exist, return HTTP status 404 | 
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|  | 115 | (not found)</li> | 
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|  | 116 | <li>Unbind the resource from the directory context containing the | 
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|  | 117 | static resources for this web application.  If successful, return | 
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|  | 118 | HTTP status 204 (no content).  Otherwise, return HTTP status 405 | 
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|  | 119 | (method not allowed).</li> | 
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|  | 120 | </ul> | 
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|  | 121 |  | 
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|  | 122 |  | 
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|  | 123 | <p>On each HTTP GET request processed by this servlet, the following | 
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|  | 124 | processing shall be performed:</p> | 
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|  | 125 | <ul> | 
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|  | 126 | <li>If the request is for a resource under <code>/META-INF</code> or | 
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|  | 127 | <code>/WEB-INF</code>, return HTTP status 404 (not found).</li> | 
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|  | 128 | <li>If the requested resource does not exist, return HTTP status 404 | 
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|  | 129 | (not found).</li> | 
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|  | 130 | <li>If the requested resource is not a directory, but the resource | 
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|  | 131 | path ends in "/" or "\", return HTTP status 404 (not found).</li> | 
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|  | 132 | <li>If the requested resource is a directory: | 
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|  | 133 | <ul> | 
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|  | 134 | <li>If the request path does not end with "/", redirect to a | 
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|  | 135 | corresponding path with "/" appended so that relative references | 
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|  | 136 | in welcome files are resolved correctly.</li> | 
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|  | 137 | <li>If one of the specified welcome files exists, redirect to the | 
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|  | 138 | path for that welcome file so that it will be served explicitly. | 
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|  | 139 | </li> | 
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|  | 140 | </ul></li> | 
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|  | 141 | <li>If the request being processed contains an <code>If-Range</code> | 
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|  | 142 | header, perform the processing described in the HTTP/1.1 specification | 
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|  | 143 | to determine whether the client's information is up to date.</li> | 
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|  | 144 | <li>Determine the content type of the response, by looking up the | 
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|  | 145 | corresponding MIME type in our servlet context.</li> | 
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|  | 146 | <li>If the requested resource is a directory: | 
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|  | 147 | <ul> | 
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|  | 148 | <li>If directory listings are suppressed, return HTTP status 404 | 
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|  | 149 | (not found).</li> | 
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|  | 150 | <li>Set the content type to <code>text/html</code>.</li> | 
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|  | 151 | </ul></li> | 
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|  | 152 | <li>Determine the range(s) to be returned, based on the existence of | 
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|  | 153 | any <code>If-Range</code> and <code>Range</code> headers.</li> | 
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|  | 154 | <li>If the requested resource is a directory, include an <code>ETag</code> | 
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|  | 155 | header in the response, with the value calculated based on the content | 
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|  | 156 | of the directory.</li> | 
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|  | 157 | <li>Include a <code>Last-Modified</code> header in the response documenting | 
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|  | 158 | the date/time that the resource was last modified.</li> | 
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|  | 159 | <li>Unless we are processing a HEAD request, include the appropriate | 
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|  | 160 | content (or content ranges) in the response.</li> | 
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|  | 161 | </ul> | 
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|  | 162 |  | 
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|  | 163 | <p>On each HTTP HEAD request processed by this servlet, the following | 
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|  | 164 | processing shall be performed:</p> | 
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|  | 165 | <ul> | 
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|  | 166 | <li>Processed identically to an HTTP GET request, except that the data | 
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|  | 167 | content is not transmitted after the headers.</li> | 
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|  | 168 | </ul> | 
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|  | 169 |  | 
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|  | 170 | <p>On each HTTP POST request processed by this servlet, the following | 
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|  | 171 | processing shall be performed:</p> | 
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|  | 172 | <ul> | 
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|  | 173 | <li>Processed identically to an HTTP GET request.</li> | 
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|  | 174 | </ul> | 
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|  | 175 |  | 
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|  | 176 |  | 
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|  | 177 | <p>On each HTTP PUT request processed by this servlet, the following | 
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|  | 178 | processing shall be perfomred:</p> | 
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|  | 179 | <ul> | 
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|  | 180 | <li>If modifications to the static resources are not allowed (set by a | 
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|  | 181 | configuration parameter), return HTTP status 403 (forbidden).</li> | 
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|  | 182 | <li>If an attempt is made to delete a resource from <code>/META-INF</code> | 
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|  | 183 | or <code>/WEB-INF</code>, return HTTP status 403 (forbidden).</li> | 
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|  | 184 | <li>Create a new resource from the body of this request.</li> | 
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|  | 185 | <li>Bind or rebind the specified path to the new resource (depending on | 
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|  | 186 | whether it currently exists or not).  Return HTTP status as follows: | 
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|  | 187 | <ul> | 
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|  | 188 | <li>If binding was unsuccessful, return HTTP status 409 (conflict). | 
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|  | 189 | </li> | 
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|  | 190 | <li>If binding was successful and the resource did not previously | 
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|  | 191 | exist, return HTTP status 201 (created).</li> | 
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|  | 192 | <li>If binding was successful and the resource previously existed, | 
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|  | 193 | return HTTP status 204 (no content).</li> | 
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|  | 194 | </ul></li> | 
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|  | 195 | </ul> | 
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|  | 196 |  | 
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|  | 197 | </blockquote></td></tr></table> | 
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|  | 198 |  | 
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|  | 199 |  | 
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|  | 200 | <table cellpadding="2" cellspacing="0" border="0"><tr><td bgcolor="#828DA6"><font face="arial,helvetica.sanserif" color="#ffffff"><a name="Finalization Functionality"><strong>Finalization Functionality</strong></a></font></td></tr><tr><td><blockquote> | 
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|  | 201 |  | 
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|  | 202 | <p>No specific processing is required when the <code>destroy()</code> | 
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|  | 203 | method is called:</p> | 
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|  | 204 |  | 
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|  | 205 | </blockquote></td></tr></table> | 
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|  | 206 |  | 
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|  | 207 |  | 
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|  | 208 | </blockquote></td></tr></table><table cellpadding="2" cellspacing="0" border="0"><tr><td bgcolor="#525D76"><font face="arial,helvetica.sanserif" color="#ffffff"><a name="Testable Assertions"><strong>Testable Assertions</strong></a></font></td></tr><tr><td><blockquote> | 
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|  | 209 |  | 
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|  | 210 | <p>In addition the the assertions implied by the functionality requirements | 
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|  | 211 | listed above, the following additional assertions shall be tested to | 
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|  | 212 | validate the behavior of the invoker servlet:</p> | 
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|  | 213 | <ul> | 
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|  | 214 | <li>Requests for resources that do not exist in the web application must | 
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|  | 215 | return HTTP status 404 (not found).</li> | 
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|  | 216 | <li>The default servlet must operate identically for web applications that | 
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|  | 217 | are run out of a WAR file directly, or from an unpacked directory | 
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|  | 218 | structure.</li> | 
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|  | 219 | <li>If the web application is running out of an unpacked directory | 
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|  | 220 | structure, the default servlet must recognize cases where the resource | 
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|  | 221 | has been updated through external means.</li> | 
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|  | 222 | </ul> | 
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|  | 223 |  | 
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|  | 224 | </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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|  | 225 | Copyright © 1999-2008, Apache Software Foundation | 
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|  | 226 | </em></font></div></td></tr></table></body></html> | 
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