'<>' operator is not allowed for source level below 1.7

Question

I installed the DXA 1.2 JAVA web application on Tomcat with the Create-web-application-staging.bat script. Most of the site works, but the header cannot be rendered and shows an error message (see screenshot).

The logs tell me that something is wrong in the language selector.

2016-01-07 17:05:04,023 ERROR EntitiesTag - Error while processing entity tag
org.apache.jasper.JasperException: Unable to compile class for JSP:

An error occurred at line: 17 in the jsp file: /WEB-INF/Views/Core/Entity/LanguageSelector.jsp
'<>' operator is not allowed for source level below 1.7

complete log...

I am running Java 1.7 and I know that DXA is compiled for at least 1.7. The problem is in a Tomcat or JSP setting which compiles the .jsp to JAVA 1.6 profile.

How do I get Tomcat to compile this normally?

Answer 1

Add those lines to JSP servlet settings in Apache's Tomcat 7.0\conf\web.xml.

<init-param>                                    
    <param-name>compilerSourceVM</param-name>
    <param-value>1.7</param-value>
</init-param>
<init-param>
    <param-name>compilerTargetVM</param-name>
    <param-value>1.7</param-value>
</init-param>

more...

Also see https://stackoverflow.com/a/11810014/1678525 and https://tomcat.apache.org/tomcat-7.0-doc/jasper-howto.html

Answer 2

You're probably using Tomcat 7, which by default doesn't allow Java 1.7-specific stuff like diamond syntax. It can be configured to allow it, though: http://censore.blogspot.nl/2015/04/how-to-set-tomcat-7-source-level-to.html