Servlet mapping path <url-pattern> in web.xml file

September 23, 2016 21:11:59

 

 

General writing: /dir1/dir2/dir3...

<servlet-mapping>
    <servlet-name>ServletName</servlet-name>
    <url-pattern>/Servlet/ServletName</url-pattern>
</servlet-mapping>

*There are 2 ways to write wildcards: / at the beginning * at the end or *. extension

<servlet-mapping>
    <servlet-name>ServletName</servlet-name>
    <url-pattern>/*</url-pattern>
</servlet-mapping>

<servlet-mapping>
    <servlet-name>ServletName</servlet-name>
    <url-pattern>/a/b/*</url-pattern>
</servlet-mapping>

<servlet-mapping>
    <servlet-name>ServletName</servlet-name>
    <url-pattern>*.html</url-pattern>
</servlet-mapping>

If the mapping path of a servlet is only a /, then this servlet becomes the default servlet of the current web application and
it can handle requests that all other servlets do not handle
. The resource cannot be accessed, so it is intercepted and processed by this servlet

<servlet-mapping>
    <servlet-name>ServletName</servlet-name>
    <url-pattern>/</url-pattern>
</servlet-mapping>

In this case, the default Servlet provided by tomcat will be overridden. This Serlvet provides access services for static resources.
This Servlet is configured in the $tomcat/conf/web.xml file:

<servlet>
        <servlet-name>default</servlet-name>
        <servlet-class>org.apache.catalina.servlets.DefaultServlet</servlet-class>
        <init-param>
            <param-name>debug</param-name>
            <param-value>0</param-value>
        </init-param>
        <init-param>
            <param-name>listings</param-name>
            <param-value>false</param-value>
        </init-param>
        <load-on-startup>1</load-on-startup>
    </servlet>

    <servlet-mapping>
        <servlet-name>default</servlet-name>
        <url-pattern>/</url-pattern>
    </servlet-mapping>

 

For some of the following mapping relationships:

• Servlet1 maps to /abc/*
• Servlet2 maps to /*
• Servlet3 maps to /abc
• Servlet4 maps to *.do

Note:  *.do has the lowest priority