| <html><head> |
| <meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"> |
| <title>Working with Annotations</title><link rel="stylesheet" type="text/css" href="css/docbook.css"><meta name="generator" content="DocBook XSL-NS Stylesheets V1.76.1"><meta name="keywords" content="jetty, servlet, servlet-api, cometd, http, spdy, websocket, eclipse, maven, java, server, software"><link rel="home" href="index.html" title="Jetty : The Definitive Reference"><link rel="up" href="annotations.html" title="Chapter 12. Annotations"><link rel="prev" href="annotations.html" title="Chapter 12. Annotations"><link rel="next" href="using-annotations-embedded.html" title="Using Annotations with Jetty Embedded"><link xmlns:jfetch="java:org.eclipse.jetty.xslt.tools.JavaSourceFetchExtension" xmlns:fetch="java:org.eclipse.jetty.xslt.tools.SourceFetchExtension" xmlns:d="http://docbook.org/ns/docbook" xmlns:l="http://docbook.sourceforge.net/xmlns/l10n/1.0" xmlns:xslthl="http://xslthl.sf.net" xmlns:gcse="http://www.google.com" xmlns:date="http://exslt.org/dates-and-times" rel="shortcut icon" href="images/favicon.ico"><script type="text/javascript" src="js/shCore.js"></script><script type="text/javascript" src="js/shBrushJava.js"></script><script type="text/javascript" src="js/shBrushXml.js"></script><script type="text/javascript" src="js/shBrushBash.js"></script><script type="text/javascript" src="js/shBrushJScript.js"></script><script type="text/javascript" src="js/shBrushSql.js"></script><script type="text/javascript" src="js/shBrushProperties.js"></script><script type="text/javascript" src="js/shBrushPlain.js"></script><link type="text/css" rel="stylesheet" href="css/shCore.css"><link type="text/css" rel="stylesheet" href="css/shThemeEclipse.css"><link type="text/css" rel="stylesheet" href="css/font-awesome.min.css"></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><table xmlns:jfetch="java:org.eclipse.jetty.xslt.tools.JavaSourceFetchExtension" xmlns:fetch="java:org.eclipse.jetty.xslt.tools.SourceFetchExtension" xmlns:d="http://docbook.org/ns/docbook" xmlns:l="http://docbook.sourceforge.net/xmlns/l10n/1.0" xmlns:xslthl="http://xslthl.sf.net" xmlns:gcse="http://www.google.com" xmlns:date="http://exslt.org/dates-and-times"><tr><td style="width: 25%"><a href="http://www.eclipse.org/jetty"><img src="images/jetty-header-logo.png" alt="Jetty Logo"></a><br><span style="font-size: small"> |
| Version: 9.2.21.v20170120</span></td><td style="width: 50%"><script type="text/javascript"> (function() { |
| var cx = '016459005284625897022:obd4lsai2ds'; |
| var gcse = document.createElement('script'); |
| gcse.type = 'text/javascript'; |
| gcse.async = true; |
| gcse.src = (document.location.protocol == 'https:' ? 'https:' : 'http:') + |
| '//www.google.com/cse/cse.js?cx=' + cx; |
| var s = document.getElementsByTagName('script')[0]; |
| s.parentNode.insertBefore(gcse, s); |
| })(); |
| </script><gcse:search></gcse:search></td></tr></table><div xmlns:jfetch="java:org.eclipse.jetty.xslt.tools.JavaSourceFetchExtension" xmlns:fetch="java:org.eclipse.jetty.xslt.tools.SourceFetchExtension" xmlns:d="http://docbook.org/ns/docbook" xmlns:l="http://docbook.sourceforge.net/xmlns/l10n/1.0" xmlns:xslthl="http://xslthl.sf.net" xmlns:gcse="http://www.google.com" xmlns:date="http://exslt.org/dates-and-times" class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center">Working with Annotations</th></tr><tr><td width="20%" align="left"><a accesskey="p" href="annotations.html"><i class="icon-chevron-left"></i> Previous</a> </td><th width="60%" align="center">Chapter 12. Annotations<br><a accesskey="p" href="index.html"><i class="icon-home"></i> Home</a></th><td width="20%" align="right"> <a accesskey="n" href="using-annotations-embedded.html">Next <i class="icon-chevron-right"></i></a></td></tr></table><hr></div><div xmlns:jfetch="java:org.eclipse.jetty.xslt.tools.JavaSourceFetchExtension" xmlns:fetch="java:org.eclipse.jetty.xslt.tools.SourceFetchExtension" xmlns:d="http://docbook.org/ns/docbook" xmlns:l="http://docbook.sourceforge.net/xmlns/l10n/1.0" xmlns:xslthl="http://xslthl.sf.net" xmlns:gcse="http://www.google.com" xmlns:date="http://exslt.org/dates-and-times" class="jetty-callout"><h5 class="callout"><a href="http://www.webtide.com/">Contact the core Jetty developers at |
| <span class="website">www.webtide.com</span></a></h5><p> |
| private support for your internal/customer projects ... custom extensions and distributions ... versioned snapshots for indefinite support ... |
| scalability guidance for your apps and Ajax/Comet projects ... development services from 1 day to full product delivery |
| </p></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="using-annotations"></a>Working with Annotations</h2></div></div></div><div class="toc"><dl><dt><span class="section"><a href="using-annotations.html#d0e10739">Which Annotations Are Supported</a></span></dt><dt><span class="section"><a href="using-annotations.html#discoverable_introspectable_annotations">Discovered vs Introspected Annotations</a></span></dt><dt><span class="section"><a href="using-annotations.html#jars-scanned-for-annotations">Which Jars Are Scanned For Discovered Annotations</a></span></dt><dt><span class="section"><a href="using-annotations.html#d0e10891">Multi-threaded Annotation Scanning</a></span></dt><dt><span class="section"><a href="using-annotations.html#servlet-container-initializers">ServletContainerInitializers</a></span></dt></dl></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a name="d0e10739"></a>Which Annotations Are Supported</h3></div></div></div><p>Jetty supports interpretation and application of the following |
| annotations:</p><div class="itemizedlist"><ul class="itemizedlist" type="disc"><li class="listitem"><p>@Resource</p></li><li class="listitem"><p>@Resources</p></li><li class="listitem"><p>@PostConstruct</p></li><li class="listitem"><p>@PreDestroy</p></li><li class="listitem"><p>@DeclaredRoles</p></li><li class="listitem"><p>@RunAs</p></li><li class="listitem"><p>@MultipartConfig</p></li><li class="listitem"><p>@WebServlet</p></li><li class="listitem"><p>@WebFilter</p></li><li class="listitem"><p>@WebListener</p></li><li class="listitem"><p>@WebInitParam</p></li><li class="listitem"><p>@ServletSecurity, @HttpConstraint, @HttpMethodConstraint</p></li><li class="listitem"><p>@HandlesTypes (on ServletContainerInitializers)</p></li></ul></div></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a name="discoverable_introspectable_annotations"></a>Discovered vs Introspected Annotations</h3></div></div></div><p>Some types of annotation can be placed on any classes, not |
| necessarily just those with which the container interacts directly. We |
| call these type of annotations "discovered" to indicate that the container |
| must take proactive action to go out and find them. The other type of |
| annotation we call "introspected", meaning that they occur on classes with |
| which the container interacts during their lifecycle (eg |
| javax.servlet.Servlet, javax.servlet.Filter etc), and hence can be found |
| by simple inspection of the class at that point.</p><p><a name="discovered_annotations"></a>Some examples of discovered |
| annotations are:</p><div class="itemizedlist"><ul class="itemizedlist" type="disc"><li class="listitem"><p>@WebServlet</p></li><li class="listitem"><p>@WebFilter</p></li><li class="listitem"><p>@WebListener</p></li></ul></div><p>Some examples of introspected annotations are:</p><div class="itemizedlist"><ul class="itemizedlist" type="disc"><li class="listitem"><p>@PostConstruct</p></li><li class="listitem"><p>@PreDestroy</p></li><li class="listitem"><p>@Resource</p></li></ul></div></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a name="jars-scanned-for-annotations"></a>Which Jars Are Scanned For Discovered Annotations</h3></div></div></div><p>The web.xml file can contain the attribute |
| <code class="code">metadata-complete</code>. If this is set to <code class="code">true</code>, then |
| <span class="emphasis"><em>no</em></span> scanning of discoverable annotations takes place. |
| However, scanning of classes may <span class="emphasis"><em>still</em></span> occur because |
| of <a class="link" href="http://docs.oracle.com/javaee/6/api/javax/servlet/ServletContainerInitializer.html" target="_top">javax.servlet.ServletContainerInitializer</a>s. |
| Classes implementing this interface are found by Jetty using the <a class="link" href="http://docs.oracle.com/javase/6/docs/api/java/util/ServiceLoader.html" target="_top">javax.util.ServiceLoader</a> |
| mechanism, and if one is present <span class="emphasis"><em>and</em></span> it includes the |
| @HandlesTypes annotation, then Jetty must scan the class hierarchy of the |
| web application. This may be very time-consuming if you have many jars in |
| the container's path or in the webapp's WEB-INF/lib.</p><p>If scanning is to take place - because either |
| <code class="code">metadata-complete</code> is <code class="code">false</code> or missing, or |
| because there are one or more <a class="link" href="http://docs.oracle.com/javaee/6/api/javax/servlet/ServletContainerInitializer.html" target="_top">javax.servlet.ServletContainerIntializer</a>s |
| with @HandlesTypes - then Jetty must consider both the container's |
| classpath and the webapp's classpath.</p><p>By default, Jetty will <span class="emphasis"><em>not</em></span> scan any classes |
| that are on the container's classpath. If you need to cause jars and |
| classes that are on the container's classpath to be scanned, then you can |
| use the <a class="link" href="configuring-webapps.html#container-include-jar-pattern" title="org.eclipse.jetty.server.webapp.ContainerIncludeJarPattern">org.eclipse.jetty.server.webapp.ContainerIncludeJarPattern</a> |
| <a class="link" href="quickstart-config-what.html#context_attributes">context attribute</a> to specify a |
| pattern for jars and directories from the container's classpath to |
| scan.</p><p>By default, Jetty will scan <span class="emphasis"><em>all </em></span>classes from |
| <code class="code">WEB-INF/classes</code>, and all jars from <code class="code">WEB-INF/lib</code> |
| according to the order, if any, established by absolute or relative |
| ordering clauses in web.xml. If your webapp contains many jars, you can |
| significantly speed up deployment by omitting them from scanning. To do |
| this, use the <a class="link" href="configuring-webapps.html#web-inf-include-jar-pattern" title="org.eclipse.jetty.server.webapp.WebInfIncludeJarPattern">org.eclipse.jetty.server.webapp.WebInfIncludeJarPattern</a> |
| <a class="link" href="quickstart-config-what.html#context_attributes">context attribute</a> to define the |
| patterns of jars that you specifically want to be scanned.</p><p>Note that if you have configured an <a class="link" href="jetty-classloading.html#using-extra-classpath-method" title="Using the extraClasspath() method">extraClasspath</a> for the |
| webapp, then it participates in the scanning process too. Any classes dirs |
| are treated the same for scanning purposes as if they were in |
| WEB-INF/classes and jars are treated as if they were in |
| WEB-INF/lib.</p><p>See also the next section on <a class="link" href="using-annotations.html#servlet-container-initializers" title="ServletContainerInitializers">ServletContainerInitializers</a> |
| if you need to <a class="link" href="using-annotations.html#servlet-container-initializers" title="ServletContainerInitializers">control the |
| order in which they are applied</a>.</p></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a name="d0e10891"></a>Multi-threaded Annotation Scanning</h3></div></div></div><p>Since jetty-9.1,<a class="link" href="using-annotations.html#jars-scanned-for-annotations" title="Which Jars Are Scanned For Discovered Annotations"> |
| if annotation scanning is to be performed</a>, by default Jetty will do |
| it in a multi-threaded manner in order to complete it in the minimum |
| amount of time.</p><p>If for some reason you don't want to do it multi-threaded, you can |
| configure Jetty to revert to single-threaded scanning. You have several |
| ways to configure this:</p><div class="orderedlist"><ol class="orderedlist" type="1"><li class="listitem"><p>set the <a class="link" href="quickstart-config-what.html#context_attributes">context |
| attribute</a> |
| <code class="code">org.eclipse.jetty.annotations.multiThreaded</code> to |
| <code class="code">false</code></p></li><li class="listitem"><p>set the <a class="link" href="quickstart-config-what.html#server_attributes">Server |
| attribute</a> |
| <code class="code">org.eclipse.jetty.annotations.multiThreaded</code> to |
| <code class="code">false</code></p></li><li class="listitem"><p>set the System property |
| <code class="code">org.eclipse.jetty.annotations.multiThreaded</code> to |
| <code class="code">false</code></p></li></ol></div><p>Method 1 will only affect the current webapp. Method 2 will affect |
| all webapps deployed to the same Server instance. Method 3 will affect all |
| webapps deployed in the same jvm.</p><p>By default, Jetty will wait a maximum of 60 seconds for all of the |
| scanning threads to complete. You can set this to a higher or lower number |
| of seconds by doing one of the following:</p><div class="orderedlist"><ol class="orderedlist" type="1"><li class="listitem"><p>set the <a class="link" href="quickstart-config-what.html#context_attributes">context |
| attribute</a> |
| <code class="code">org.eclipse.jetty.annotations.maxWait</code></p></li><li class="listitem"><p>set the <a class="link" href="quickstart-config-what.html#server_attributes">Server |
| attribute</a> |
| <code class="code">org.eclipse.jetty.annotations.maxWait</code></p></li><li class="listitem"><p>set the System property |
| <code class="code">org.eclipse.jetty.annotations.maxWait</code></p></li></ol></div><p>Method 1 will only affect the current webapp. Method 2 will affect |
| all webapps deployed to the same Server instance. Method 3 will affect all |
| webapps deployed in the same jvm.</p></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a name="servlet-container-initializers"></a>ServletContainerInitializers</h3></div></div></div><p><a class="link" href="http://docs.oracle.com/javaee/6/api/javax/servlet/ServletContainerInitializer.html" target="_top">javax.servlet.ServletContainerInitializers</a> |
| can exist in: the container's classpath, the webapp's WEB-INF/classes |
| directory, the webapp's WEB-INF/lib jars, or any external <a class="link" href="jetty-classloading.html#using-extra-classpath-method" title="Using the extraClasspath() method">extraClasspath</a> that you have |
| configured on the webapp.</p><p>The <a class="link" href="http://jcp.org/aboutJava/communityprocess/final/jsr340/" target="_top">Servlet |
| Specification</a> does not define any order in which these |
| ServletContainerInitializers must be called when the webapp starts. Since |
| jetty-9.1, by default Jetty will call them in the following |
| order:</p><div class="orderedlist"><ol class="orderedlist" type="1"><li class="listitem"><p>ServletContainerInitializers from the container's |
| classpath</p></li><li class="listitem"><p>ServletContainerInitializers from WEB-INF/classes</p></li><li class="listitem"><p>ServletContainerInitializers from WEB-INF/lib jars i<span class="emphasis"><em>n |
| the order established in web.xml</em></span>, or in the order that the |
| SCI is returned by the <a class="link" href="http://docs.oracle.com/javase/6/docs/api/java/util/ServiceLoader.html" target="_top">javax.util.ServiceLoader</a> |
| if there is <span class="emphasis"><em>no</em></span> ordering</p></li></ol></div><p>As is the case with annotation scanning, the <a class="link" href="jetty-classloading.html#using-extra-classpath-method" title="Using the extraClasspath() method">extraClasspath</a> is fully |
| considered for ServletContainerInitializer callbacks. |
| ServletContainerInitializers derived from a classes dir on the |
| extraClasspath and jars from an extraClasspath for the webapp are called |
| in step 2 and 3 respectively.</p><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="d0e10999"></a>Controlling the order of ServletContainerInitializer |
| invocation</h4></div></div></div><div class="section"><div class="titlepage"></div><p>If you need ServletContainerInitializers called in a specific |
| order that is different from that outlined above, then you can use the |
| <a class="link" href="quickstart-config-what.html#context_attributes">context attribute</a> |
| <code class="code">org.eclipse.jetty.containerInitializerOrder</code>. Set it to a |
| list of comma separated class names of ServletContainerInitializers in |
| the order that you want them applied. You may optionally use the |
| wildcard character "*" <span class="bold"><strong>once</strong></span> in the |
| list. It will match all ServletContainerInitializers not explicitly |
| named in the list. Here's an example, setting the context attribute in |
| code (although you can also do the <a class="link" href="quickstart-config-what.html#intro-jetty-configuration-webapps" title="Configuring Web Applications">same in |
| xml</a>):</p><script type="syntaxhighlighter" class="brush: java;toolbar: false"> |
| <![CDATA[WebAppContext context = new WebAppContext(); |
| context.setAttribute("org.eclipse.jetty.containerInitializerOrder", |
| "org.eclipse.jetty.websocket.jsr356.server.deploy.WebSocketServerContainerInitializer, com.acme.Foo.MySCI, *");]]> |
| </script><p>In this example, we ensure that the |
| WebSocketServerContainerInitializer is the very first |
| ServletContainerInitializer that is called, followed by MySCI and then |
| any other ServletContainerInitializers that were discovered but not |
| yet called.</p></div></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a name="d0e11021"></a>Excluding ServletContainerInitializers</h4></div></div></div><p>By default, as according to the Servlet Specification, all |
| ServletContainerInitializers that are discovered are invoked (see above |
| for how to control the invocation order). Sometimes, you may need to |
| prevent some being called at all.</p><p>In this case, you can define the |
| <code class="code">org.eclipse.jetty.containerInitializerExclusionPattern</code> |
| <a class="link" href="quickstart-config-what.html#context_attributes">context attribute</a>. This is a |
| regular expression that defines <a class="link" href="http://docs.oracle.com/javase/7/docs/api/java/util/regex/Pattern.html" target="_top">patterns</a> |
| of classnames that you want to exclude. Here's an example, setting the |
| context attribute in code, although you may do exactly the <a class="link" href="quickstart-config-what.html#intro-jetty-configuration-webapps" title="Configuring Web Applications">same in xml</a>:</p><p><script type="syntaxhighlighter" class="brush: java;toolbar: false"> |
| <![CDATA[WebAppContext context = new WebAppContext(); |
| context.setAttribute("org.eclipse.jetty.containerInitializerExclusionPattern", |
| "com.acme.*|com.corp.SlowContainerInitializer");]]> |
| </script>In |
| this example we exclude <span class="bold"><strong>all</strong></span> |
| ServletContainerInitializers in the com.acme package, and the |
| SlowContainerInitializer.</p><p>It is possible to use exclusion and ordering together to control |
| ServletContainerInitializer invocation - the exclusions will be applied |
| before the ordering.</p></div></div></div><script type="text/javascript"> |
| SyntaxHighlighter.all() |
| </script><div class="navfooter"><hr><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="annotations.html"><i class="icon-chevron-left"></i> Previous</a> </td><td width="20%" align="center"><a accesskey="u" href="annotations.html"><i class="icon-chevron-up"></i> Top</a></td><td width="40%" align="right"> <a accesskey="n" href="using-annotations-embedded.html">Next <i class="icon-chevron-right"></i></a></td></tr><tr><td width="40%" align="left" valign="top">Chapter 12. Annotations </td><td width="20%" align="center"><a accesskey="h" href="index.html"><i class="icon-home"></i> Home</a></td><td width="40%" align="right" valign="top"> Using Annotations with Jetty Embedded</td></tr></table></div><p xmlns:jfetch="java:org.eclipse.jetty.xslt.tools.JavaSourceFetchExtension" xmlns:fetch="java:org.eclipse.jetty.xslt.tools.SourceFetchExtension" xmlns:d="http://docbook.org/ns/docbook" xmlns:l="http://docbook.sourceforge.net/xmlns/l10n/1.0" xmlns:xslthl="http://xslthl.sf.net" xmlns:gcse="http://www.google.com" xmlns:date="http://exslt.org/dates-and-times"><div class="jetty-callout"> |
| See an error or something missing? |
| <span class="callout"><a href="http://github.com/jetty-project/jetty-documentation">Contribute to this documentation at |
| <span class="website"><i class="icon-github"></i> Github!</span></a></span><span style="float: right"><i>(Generated: 2015-03-13T11:47:51-05:00)</i></span></div></p><script xmlns:jfetch="java:org.eclipse.jetty.xslt.tools.JavaSourceFetchExtension" xmlns:fetch="java:org.eclipse.jetty.xslt.tools.SourceFetchExtension" xmlns:d="http://docbook.org/ns/docbook" xmlns:l="http://docbook.sourceforge.net/xmlns/l10n/1.0" xmlns:xslthl="http://xslthl.sf.net" xmlns:gcse="http://www.google.com" xmlns:date="http://exslt.org/dates-and-times" type="text/javascript"> |
| var _gaq = _gaq || []; |
| _gaq.push(['_setAccount', 'UA-1149868-7']); |
| _gaq.push(['_trackPageview']); |
| |
| (function() { |
| var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true; |
| ga.src = ('https:' == document.location.protocol ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js'; |
| var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s); |
| })(); |
| </script></body></html> |
