S2 Tip – Maintain configuration files in a resource folder or Java package

The default struts.xml file is loaded from the root of the classpath. In a web application, the WEB-INF/classes folder is loaded to the root of the classpath.

To avoid maintaining files directly under WEB-INF, create a resource folder that can be copied to WEB-INF/classes when the appliication is compiled. If subfolders are also copied, then the resource folder can mirror the Java package system. The Struts Showcase application uses this common approach.

+ java

  + receivables

    - Deposit.java

    - Menu.java

  + payables

    - Menu.java

+ resources

  - payables.xml

  - receivables.xml

  - struts.xml

  + payables

    - Menu.properties

  + receivables

    - Menu.properties

+ webapp

  + payables

  + receivables

    - Deposit-error.jsp

    - Deposit-input.jsp

  + WEB-INF

Alternatively, maintain the configuration files alongside the Java packages, and have the build system copy resource files from the Java source root. The Struts Mailreader uses this alternative approach.

+ java

+ receivables

- struts.xml

- Deposit.java

- Menu.java

- Menu.properties

+ payables

- struts.xml

- Menu.java

- Menu.properties

- struts.xml

+ webapp

+ receivables

- Deposit-error.jsp

- Deposit-input.jsp

+ payables

+ WEB-INF

If FreeMarker templates are used in lieu of JSPs, then all the resources for a namespace can be kept in a single folder.

+ java

+ receivables

- struts.xml

- Deposit.java

- Deposit-input.ftl

- Deposit-error.ftl

- Menu.java

- Menu.properties

+ payables

- struts.xml

- Menu.java

- Menu.properties

- struts.xml

S2 Tips – Try to keep the Action classes for the namespace in a common Java package

As part of the Struts 2 from Square One project, I’ve been reducing the Struts 2 tips to a manuscript. One Struts Tip a week isn’t keeping up with the manuscript, so I’ll be running two a day for the rest of the week.

An element of Java style is to place types that are common used together into the same package. If namespaces are being used to organize an application, then the Actions within a namespace should be found in the same Java package.