docs/org.eclipse.wst.webtools.doc.user/topics/twfltwiz.html - sourceediting/webtools.sourceediting - Git at Google

 <?xml version="1.0" encoding="UTF-8"?><!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
 <html lang="en-us" xml:lang="en-us">
 <head>
 <meta content="text/html; charset=utf-8" http-equiv="Content-Type" />
 <meta name="copyright" content="Copyright (c) 2000, 2008 IBM Corporation and others. All rights reserved. This program and the accompanying materials are made available under the terms of the Eclipse Public License v1.0 which accompanies this distribution, and is available at http://www.eclipse.org/legal/epl-v10.html. Contributors: IBM Corporation - initial API and implementation" />
 <meta name="DC.rights.owner" content="(C) Copyright 2000, 2008" />
 <meta content="public" name="security" />
 <meta content="index,follow" name="Robots" />
 <meta http-equiv="PICS-Label" content='(PICS-1.1 "http://www.icra.org/ratingsv02.html" l gen true r (cz 1 lz 1 nz 1 oz 1 vz 1) "http://www.rsac.org/ratingsv01.html" l gen true r (n 0 s 0 v 0 l 0) "http://www.classify.org/safesurf/" l gen true r (SS~~000 1))' />
 <meta content="task" name="DC.Type" />
 <meta name="DC.Title" content="Creating Filters" />
 <meta name="abstract" content="The filters wizard helps you to create Java servlet filters by walking you through the creation process and by providing you with output files that you can use or that you can modify for use with your Web application. The filters can run on Java EE-compliant Web servers." />
 <meta name="description" content="The filters wizard helps you to create Java servlet filters by walking you through the creation process and by providing you with output files that you can use or that you can modify for use with your Web application. The filters can run on Java EE-compliant Web servers." />
 <meta content="servlets, creating" name="DC.subject" />
 <meta content="servlets, creating" name="keywords" />
 <meta scheme="URI" name="DC.Relation" content="../topics/cwfiltbn.html" />
 <meta content="XHTML" name="DC.Format" />
 <meta content="twfltwiz" name="DC.Identifier" />
 <meta content="en-us" name="DC.Language" />
 <link href="../../org.eclipse.wst.doc.user/common.css" type="text/css" rel="stylesheet" />
 <title>Creating Filters</title>
 </head>
 <body id="twfltwiz"><a name="twfltwiz"><!-- --></a>


 <h1 class="topictitle1">Creating Filters</h1>


 <div><p>The filters wizard helps you to create Java™ servlet filters by walking you through
 the creation process and by providing you with output files that you can use
 or that you can modify for use with your Web application. The filters can
 run on Java EE-compliant Web servers.</p>

 <div class="section"> <p>To create a filter, complete the following steps: </p>
 </div>

 <ol>
 <li class="stepexpand"><span>In the Java EE perspective, expand your  <a href="ccwebprj.html" title="">dynamic project</a> in the Project Explorer view.</span>
 </li>

 <li class="stepexpand"><span>Right click on the <strong>Filter</strong> icon, and select <span class="menucascade">
 <span class="uicontrol">New</span> &gt; <span class="uicontrol">Filter</span></span> from
 the pop-up menu.</span>  The <span class="uicontrol">Create Filter</span> wizard
 appears.</li>

 <li class="stepexpand"><span>Follow the project wizard prompts.</span></li>

 </ol>

 <div class="section"><p><strong>General Information</strong></p>
 <dl>
 <dt class="dlterm">Modifiers</dt>

 <dd>The <cite>Sun Microsystems Java Servlet 2.3 Specification</cite> states
 that a Servlet class must be <strong>public</strong> and not <strong>abstract</strong>. Therefore,
 you cannot change these modifiers. The only one available for change is the <strong>final</strong> modifier.</dd>


 <dt class="dlterm">Interfaces</dt>

 <dd>There is one obligatory interface that filter classes must implement: <strong>javax.servlet.Filter</strong>.
 This interface is provided by javax.servlet package and is used to represent
 the life-cycle of the filter. This interface has three methods: init, doFilter
 and destroy. <ul>
 <li>The <strong>init</strong> method is called by the servlet container only once, when
 it finishes instantiating the filter.</li>

 <li>The<strong>doFilter</strong> method is where the filtering is performed and is called
 every time a user requests a resource, such as a servlet, to which the filter
 is mapped.</li>

 <li>The <strong>destroy</strong> method is called by the servlet container to tell the
 filter that it will be taken out of service.</li>

 </ul>
  Although, that the javax.servlet.Filter interface is provided in the <strong>Interfaces</strong> field
 by default, you can add additional interfaces to implement by using the <strong>Add</strong> button.</dd>


 <dt class="dlterm">Interface selection dialog</dt>

 <dd>This dialog appears if you select to add an interface to your filter.
 As you type the name of the interface that you are adding, a list of available
 interfaces listed in the <strong>Matching items</strong> list box updates dynamically
 to display only the interfaces that match the pattern. Choose an interface
 to see the qualifier, and then click <strong>OK</strong> when finished.</dd>


 <dt class="dlterm">Filter Mappings</dt>

 <dd>For a filter to intercept a request to a servlet, you must: <ol>
 <li>declare the filter with a <strong>&lt;filter&gt;</strong> element in the deployment
 descriptor</li>

 <li>map the filter to the servlet using the <strong>&lt;filter-mapping&gt;</strong>
 element.</li>

 </ol>
  Sometimes you want a filter to work on multiple servlets. You can do
 this by mapping a filter to a URL pattern so that any request that matches
 that URL pattern will be filtered. All this is made automatically if you use
 the <strong>Filter Mappings</strong> field.</dd>


 <dt class="dlterm">Method stubs</dt>

 <dd>Because each filter must implement the javax.servlet.Filter interface,
 the <strong>Inherited abstract methods</strong> option is always checked and cannot
 be changed.</dd>

 </dl>
 </div>

 </div>

 <div><div class="relconcepts"><strong>Related concepts</strong><br />
 <div><a href="../topics/cwfiltbn.html">Filters</a></div>
 </div>
 </div>

 </body>
 </html>
	<?xml version="1.0" encoding="UTF-8"?><!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
	<html lang="en-us" xml:lang="en-us">
	<head>
	<meta content="text/html; charset=utf-8" http-equiv="Content-Type" />
	<meta name="copyright" content="Copyright (c) 2000, 2008 IBM Corporation and others. All rights reserved. This program and the accompanying materials are made available under the terms of the Eclipse Public License v1.0 which accompanies this distribution, and is available at http://www.eclipse.org/legal/epl-v10.html. Contributors: IBM Corporation - initial API and implementation" />
	<meta name="DC.rights.owner" content="(C) Copyright 2000, 2008" />
	<meta content="public" name="security" />
	<meta content="index,follow" name="Robots" />
	<meta http-equiv="PICS-Label" content='(PICS-1.1 "http://www.icra.org/ratingsv02.html" l gen true r (cz 1 lz 1 nz 1 oz 1 vz 1) "http://www.rsac.org/ratingsv01.html" l gen true r (n 0 s 0 v 0 l 0) "http://www.classify.org/safesurf/" l gen true r (SS~~000 1))' />
	<meta content="task" name="DC.Type" />
	<meta name="DC.Title" content="Creating Filters" />
	<meta name="abstract" content="The filters wizard helps you to create Java servlet filters by walking you through the creation process and by providing you with output files that you can use or that you can modify for use with your Web application. The filters can run on Java EE-compliant Web servers." />
	<meta name="description" content="The filters wizard helps you to create Java servlet filters by walking you through the creation process and by providing you with output files that you can use or that you can modify for use with your Web application. The filters can run on Java EE-compliant Web servers." />
	<meta content="servlets, creating" name="DC.subject" />
	<meta content="servlets, creating" name="keywords" />
	<meta scheme="URI" name="DC.Relation" content="../topics/cwfiltbn.html" />
	<meta content="XHTML" name="DC.Format" />
	<meta content="twfltwiz" name="DC.Identifier" />
	<meta content="en-us" name="DC.Language" />
	<link href="../../org.eclipse.wst.doc.user/common.css" type="text/css" rel="stylesheet" />
	<title>Creating Filters</title>
	</head>
	<body id="twfltwiz"><a name="twfltwiz"><!-- --></a>


	<h1 class="topictitle1">Creating Filters</h1>



	<div><p>The filters wizard helps you to create Java™ servlet filters by walking you through
	the creation process and by providing you with output files that you can use
	or that you can modify for use with your Web application. The filters can
	run on Java EE-compliant Web servers.</p>

	<div class="section"> <p>To create a filter, complete the following steps: </p>
	</div>

	<ol>
	<li class="stepexpand"><span>In the Java EE perspective, expand your <a href="ccwebprj.html" title="">dynamic project</a> in the Project Explorer view.</span>
	</li>

	<li class="stepexpand"><span>Right click on the <strong>Filter</strong> icon, and select <span class="menucascade">
	<span class="uicontrol">New</span> > <span class="uicontrol">Filter</span></span> from
	the pop-up menu.</span> The <span class="uicontrol">Create Filter</span> wizard
	appears.</li>

	<li class="stepexpand"><span>Follow the project wizard prompts.</span></li>

	</ol>

	<div class="section"><p><strong>General Information</strong></p>
	<dl>
	<dt class="dlterm">Modifiers</dt>

	<dd>The <cite>Sun Microsystems Java Servlet 2.3 Specification</cite> states
	that a Servlet class must be <strong>public</strong> and not <strong>abstract</strong>. Therefore,
	you cannot change these modifiers. The only one available for change is the <strong>final</strong> modifier.</dd>


	<dt class="dlterm">Interfaces</dt>

	<dd>There is one obligatory interface that filter classes must implement: <strong>javax.servlet.Filter</strong>.
	This interface is provided by javax.servlet package and is used to represent
	the life-cycle of the filter. This interface has three methods: init, doFilter
	and destroy. <ul>
	<li>The <strong>init</strong> method is called by the servlet container only once, when
	it finishes instantiating the filter.</li>

	<li>The<strong>doFilter</strong> method is where the filtering is performed and is called
	every time a user requests a resource, such as a servlet, to which the filter
	is mapped.</li>

	<li>The <strong>destroy</strong> method is called by the servlet container to tell the
	filter that it will be taken out of service.</li>

	</ul>
	Although, that the javax.servlet.Filter interface is provided in the <strong>Interfaces</strong> field
	by default, you can add additional interfaces to implement by using the <strong>Add</strong> button.</dd>


	<dt class="dlterm">Interface selection dialog</dt>

	<dd>This dialog appears if you select to add an interface to your filter.
	As you type the name of the interface that you are adding, a list of available
	interfaces listed in the <strong>Matching items</strong> list box updates dynamically
	to display only the interfaces that match the pattern. Choose an interface
	to see the qualifier, and then click <strong>OK</strong> when finished.</dd>


	<dt class="dlterm">Filter Mappings</dt>

	<dd>For a filter to intercept a request to a servlet, you must: <ol>
	<li>declare the filter with a <strong><filter></strong> element in the deployment
	descriptor</li>

	<li>map the filter to the servlet using the <strong><filter-mapping></strong>
	element.</li>

	</ol>
	Sometimes you want a filter to work on multiple servlets. You can do
	this by mapping a filter to a URL pattern so that any request that matches
	that URL pattern will be filtered. All this is made automatically if you use
	the <strong>Filter Mappings</strong> field.</dd>


	<dt class="dlterm">Method stubs</dt>

	<dd>Because each filter must implement the javax.servlet.Filter interface,
	the <strong>Inherited abstract methods</strong> option is always checked and cannot
	be changed.</dd>

	</dl>
	</div>

	</div>

	<div><div class="relconcepts"><strong>Related concepts</strong><br />
	<div><a href="../topics/cwfiltbn.html">Filters</a></div>
	</div>
	</div>

	</body>
	</html>