Filter过滤器中要注意的web.xml的事项_filter 失败 1025-优快云博客

本文链接：https://blog.youkuaiyun.com/LGJ1025/article/details/8252597

本文介绍如何在Web应用中配置不同类型的过滤器，包括全局资源过滤、特定文件类型过滤、目录过滤、特定servlet过滤及单一文件过滤等。通过具体示例展示了如何使用`<filter>`和`<filter-mapping>`来实现这些过滤需求。

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1。如果要映射过滤应用程序中所有资源：
<filter>
<filter-name>loggerfilter</filter-name>
<filter-class>myfilter.LoggerFilter</filter-class>
</filter>
<filter-mapping>
<filter-name>loggerfilter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
2.过滤指定的类型文件资源
<filter>
<filter-name>loggerfilter</filter-name>
<filter-class>myfilter.LoggerFilter</filter-class>
</filter>
<filter-mapping>
<filter-name>loggerfilter</filter-name>
<url-pattern>*.html</url-pattern>
</filter-mapping>
其中<url-pattern>*.html</url-pattern>要过滤jsp那么就改*.html为*.jsp,但是注意没有“/”斜杠
如果要同时过滤多种类型资源：
<filter>
<filter-name>loggerfilter</filter-name>
<filter-class>myfilter.LoggerFilter</filter-class>
</filter>
<filter-mapping>
<filter-name>loggerfilter</filter-name>
<url-pattern>*.html</url-pattern>
</filter-mapping>
<filter-mapping>
<filter-name>loggerfilter</filter-name>
<url-pattern>*.jsp</url-pattern>
</filter-mapping>
3.过滤指定的目录
<filter>
<filter-name>loggerfilter</filter-name>
<filter-class>myfilter.LoggerFilter</filter-class>
</filter>
<filter-mapping>
<filter-name>loggerfilter</filter-name>
<url-pattern>/folder_name/*</url-pattern>
</filter-mapping>
4.过滤指定的servlet
<filter>
<filter-name>loggerfilter</filter-name>
<filter-class>myfilter.LoggerFilter</filter-class>
</filter>
<filter-mapping>
<filter-name>loggerfilter</filter-name>
<servlet-name>loggerservlet</servlet-name>
</filter-mapping>
<servlet>
<servlet-name>loggerservlet</servlet-name>
<servlet-class>myfilter.LoggerServlet</servlet-class>
</servlet>
5.过滤指定文件
<filter>
<filter-name>loggerfilter</filter-name>
<filter-class>myfilter.LoggerFilter</filter-class>
</filter>
<filter-mapping>
<filter-name>loggerfilter</filter-name>
<url-pattern>/simplefilter.html</url-pattern>
</filter-mapping>
以上都要注意是否有斜杠“/”