servlet mapping

[Amol Fuke]

Hi ,

In head first book , page 587 ,

Question:
For this request ,
http://localhost:8080/MapTest/fooStuff/bar/foo.fo
what would be the container's choice among the following mappings ?

  
<servlet>
<servlet-name>two</servlet-name>
<servlet-class>foo.DeploymentTestTwo</servlet-class>
</servlet>
 
<servlet-mapping>
<servlet-name>two</servlet-name>
<url-pattern>/fooStuff/bar</url-pattern>
</servlet-mapping>
 
<servlet>
<servlet-name>three</servlet-name>
<servlet-class>foo.DeploymentTestThree</servlet-class>
</servlet>
 
<servlet-mapping>
<servlet-name>three</servlet-name>
<url-pattern>/fooStuff/*</url-pattern>
</servlet-mapping>
 
  

The answer is Three.Can somebody explains me how the answer is Three ?

Thanks,
Amol

[Ulf Dittmer]

The pattern "/fooStuff/bar" doesn't match the URL; since it doesn't contain a wildcard it requires an exact match.

If the pattern were "/fooStuff/bar/*" then it would be matched instead of "/fooStuff/*" because it is more specific.

[Kunal Jag]

Following are different match types one can define in the Deployment Descriptor (DD) web.xml file.

Exact Match
An exact match ends with an extension, like .do or .process. This type of match has the highest priority and resolved first if one such exists.

Example:

<url-pattern>
/process.do
< /url-pattern>

Directory Match
A directory match ends with an asterisk (*).
Example:

<servlet-mapping>
<servlet-name>three</servlet-name>
<url-pattern>/fooStuff/*</url-pattern>
</servlet-mapping>

Extension Match
Extension MatchStarts with an asterisk and ends with an extension. This type of match has the least priority and resolved if the other two match types are not resolved.

Example:

<url-pattern>
*.do
< /url-pattern>

[Amol Fuke]

Thanks Ulf and Kunal !

- Amol