blocks|key|848757|text|Servlet+3.0规范似乎没有提供关于容器应该如何对通过注释声明的过滤器进行排序的提示。不过，很清楚如何通过web.xml文件中的声明对过滤器进行排序。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|848758|注意安全。使用具有相互依赖性的web.xml文件顺序筛选器。尽量使您的过滤器的所有顺序独立，以最大限度地减少使用web.xml文件的需要。|848759|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|F|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|G|8|@]|9|@]|A|$]]|$1|D|3|-4|5|6|7|H|8|@]|9|@]|A|$]]]|E|$]]

The Servlet 3.0 spec doesn't seem to provide a hint on how a container should order filters that have been declared via annotations. It is clear how about how to order filters via their declaration in the web.xml file, though.

Be safe. Use the web.xml file order filters that have interdependencies. Try to make your filters all order independent to minimize the need to use a web.xml file.

blocks|key|848800|text|您确实不能使用@WebFilter注释来定义过滤器的执行顺序。但是，为了最大限度地减少web.xml使用量，只需使用filterName注释所有过滤器就足够了，这样您就不需要<filter>定义，只需要按所需的顺序使用<filter-mapping>定义即可。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|848801|例如,|848802|@WebFilter(filterName="filter1")
public+class+Filter1+implements+Filter+{}

@WebFilter(filterName="filter2")
public+class+Filter2+implements+Filter+{}|code-block|syntax|javascript|848803|在web.xml中，仅仅是这样：|848804|<filter-mapping>
++++<filter-name>filter1</filter-name>
++++<url-pattern>/url1/*</url-pattern>
</filter-mapping>
<filter-mapping>
++++<filter-name>filter2</filter-name>
++++<url-pattern>/url2/*</url-pattern>
</filter-mapping>|848805|如果你想在@WebFilter中保留URL模式，那么你可以这样做，|848806|@WebFilter(filterName="filter1",+urlPatterns="/url1/*")
public+class+Filter1+implements+Filter+{}

@WebFilter(filterName="filter2",+urlPatterns="/url2/*")
public+class+Filter2+implements+Filter+{}|848807|但是您仍然应该将<url-pattern>保留在web.xml中，因为它是XSD所必需的，尽管它可以是空的：|848808|<filter-mapping>
++++<filter-name>filter1</filter-name>
++++<url-pattern+/>
</filter-mapping>
<filter-mapping>
++++<filter-name>filter2</filter-name>
++++<url-pattern+/>
</filter-mapping>|848809|不管采用哪种方法，在Tomcat7.0.28之前的版本中，这一切都将失败，因为它会在没有<filter>的情况下抑制<filter-mapping>的存在。另请参阅Using+Tomcat,+@WebFilter+doesn't+work+with++inside+web.xml|848810|entityMap|0|LINK|mutability|MUTABLE|url|http://download.oracle.com/javaee/6/api/javax/servlet/annotation/WebFilter.html|1|https://stackoverflow.com/questions/10856866/using-tomcat-webfilter-doesnt-work-with-filter-mapping-inside-web-xml/10873185#10873185^0|7|A|17|7|1M|A|2F|8|31|G|7|A|0|0|0|0|1|7|0|0|5|A|0|0|8|D|O|7|0|0|18|8|1M|G|2A|1M|1|0^^$0|@$1|2|3|4|5|6|7|1A|8|@$9|1B|A|1C|B|C]|$9|1D|A|1E|B|C]|$9|1F|A|1G|B|C]|$9|1H|A|1I|B|C]|$9|1J|A|1K|B|C]]|D|@$9|1L|A|1M|1|1N]]|E|$]]|$1|F|3|G|5|6|7|1O|8|@]|D|@]|E|$]]|$1|H|3|I|5|J|7|1P|8|@]|D|@]|E|$K|L]]|$1|M|3|N|5|6|7|1Q|8|@$9|1R|A|1S|B|C]]|D|@]|E|$]]|$1|O|3|P|5|J|7|1T|8|@]|D|@]|E|$K|L]]|$1|Q|3|R|5|6|7|1U|8|@$9|1V|A|1W|B|C]]|D|@]|E|$]]|$1|S|3|T|5|J|7|1X|8|@]|D|@]|E|$K|L]]|$1|U|3|V|5|6|7|1Y|8|@$9|1Z|A|20|B|C]|$9|21|A|22|B|C]]|D|@]|E|$]]|$1|W|3|X|5|J|7|23|8|@]|D|@]|E|$K|L]]|$1|Y|3|Z|5|6|7|24|8|@$9|25|A|26|B|C]|$9|27|A|28|B|C]]|D|@$9|29|A|2A|1|2B]]|E|$]]|$1|10|3|-4|5|6|7|2C|8|@]|D|@]|E|$]]]|11|$12|$5|13|14|15|E|$16|17]]|18|$5|13|14|15|E|$16|19]]]]

You can indeed not define the filter execution order using <a href="http://download.oracle.com/javaee/6/api/javax/servlet/annotation/WebFilter.html" rel="noreferrer"><code>@WebFilter</code></a> annotation. However, to minimize the <code>web.xml</code> usage, it's sufficient to annotate all filters with just a <code>filterName</code> so that you don't need the <code>&lt;filter&gt;</code> definition, but just a <code>&lt;filter-mapping&gt;</code> definition in the desired order.

For example,

<pre class="lang-java prettyprint-override"><code>@WebFilter(filterName="filter1")
public class Filter1 implements Filter {}

@WebFilter(filterName="filter2")
public class Filter2 implements Filter {}
</code></pre>

with in <code>web.xml</code> just this:

<pre class="lang-xml prettyprint-override"><code>&lt;filter-mapping&gt;
 &lt;filter-name&gt;filter1&lt;/filter-name&gt;
 &lt;url-pattern&gt;/url1/*&lt;/url-pattern&gt;
&lt;/filter-mapping&gt;
&lt;filter-mapping&gt;
 &lt;filter-name&gt;filter2&lt;/filter-name&gt;
 &lt;url-pattern&gt;/url2/*&lt;/url-pattern&gt;
&lt;/filter-mapping&gt;
</code></pre>

If you'd like to keep the URL pattern in <code>@WebFilter</code>, then you can just do like so,

<pre class="lang-java prettyprint-override"><code>@WebFilter(filterName="filter1", urlPatterns="/url1/*")
public class Filter1 implements Filter {}

@WebFilter(filterName="filter2", urlPatterns="/url2/*")
public class Filter2 implements Filter {}
</code></pre>

but you should still keep the <code>&lt;url-pattern&gt;</code> in <code>web.xml</code>, because it's required as per XSD, although it can be empty:

<pre class="lang-xml prettyprint-override"><code>&lt;filter-mapping&gt;
 &lt;filter-name&gt;filter1&lt;/filter-name&gt;
 &lt;url-pattern /&gt;
&lt;/filter-mapping&gt;
&lt;filter-mapping&gt;
 &lt;filter-name&gt;filter2&lt;/filter-name&gt;
 &lt;url-pattern /&gt;
&lt;/filter-mapping&gt;
</code></pre>

Regardless of the approach, this all will fail in Tomcat until version 7.0.28 because it chokes on presence of <code>&lt;filter-mapping&gt;</code> without <code>&lt;filter&gt;</code>. See also <a href="https://stackoverflow.com/questions/10856866/using-tomcat-webfilter-doesnt-work-with-filter-mapping-inside-web-xml/10873185#10873185">Using Tomcat, @WebFilter doesn&#39;t work with &lt;filter-mapping&gt; inside web.xml</a>

If we define webapp specific servlet filters in WAR's own <code>web.xml</code>, then the order of execution of the filters will be the same as the order in which they are defined in the <code>web.xml</code>.

But, if we define those filters using <code>@WebFilter</code> annotation, what is the order of execution of filters, and how can we determine the order of execution?

How to define servlet filter order of execution using annotations in WAR

容器

如果我们在WAR自己的web.xml中定义特定于webapp的servlet过滤器，那么过滤器的执行顺序将与它们在web.xml中定义的顺序相同。但是，如果我们使用@WebFilter注释定义这些过滤器，那么过滤器的执行顺序是什么?我们如何确定执行的顺序？

问如何使用WAR中的注释定义servlet过滤器的执行顺序
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