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Tomcat 7

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Tomcat 7 migration

In Release 9.1 SP 14, the bundled Tomcat application server has been updated to Tomcat 7 to take advantage of new improvements, such as the Web application memory leak detection and prevention. In most circumstances this change will have no impact; however, some third-party Building Blocks may require some minor changes to work with this release.

These changes relate to additional strictness in attribute parsing and reserved words in EL language, a change in tag library declaration syntax, and a recommended change to prevent regression of context startup performance.


Annotation scanning

To ensure that startup performance is not impacted by Servlet 3.0 annotation scanning, the WEB-INF/web.xml file of all building blocks must be updated to include a metadata-complete attribute.Two options are available:

Alternatively, update to Servlet 3.0 and include the absolute-ordering element:

<web-app xmlns="http://java.sun.com/xml/ns/javaee"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"
         version="3.0"
         metadata-complete="true">
  <absolute-ordering />

To learn more about the annotation scanning changes, see http://tomcat.apache.org/migration-7.html#Annotation_scanning.


Spaces between attributes

When compiling a JSP, you may receive the error 'The JSP specification requires that an attribute name is preceded by whitespace'. Attributes previously could continue with no space, for example:

attributeOne="value1"attributeTwo="value2"

For Jasper to successfully compile, spaces need to be added in any JSP that has this problem. To learn more, see Tomcat bug 49297: https://issues.apache.org/bugzilla/show_bug.cgi?id=49297


Java reserved words in Expression Language

Expression Language tags cannot include statements that are valid Java reserved words. For example, a Bean may have a getter named getDefault(), an EL language expression would previously be able to access this with the following:

bean.default

However, this violates the reserved word strictness introduced in this release. Uses of reserved words must be updated to use the method explicitly:

bean.getDefault()

To learn more, see Tomcat bug 49217: https://issues.apache.org/bugzilla/show_bug.cgi?id=49217


Tag library declarations

Tag library declarations in WEB-INF/web.xml could previously be an immediate child of the the web-app element:

 <taglib>
  <taglib-uri>/tagLibUri</taglib-uri>
  <taglib-location>/WEB-INF/config/taglibs/tagLib.tld</taglib-location>
</taglib>

Tomcat 7 no longer supports this configuration. Custom tag libraries declared in this way must be included in a jsp-config element:

<jsp-config>
  <taglib>
    <taglib-uri>/tagLibUri</taglib-uri>
    <taglib-location>/WEB-INF/config/taglibs/tagLib.tld</taglib-location>
  </taglib>
</jsp-config>


Learn more

To learn more about the potential breaking changes caused by the migration from Tomcat 6 to 7, see http://tomcat.apache.org/migration-7...6.0.x_to_7.0.x.