Create object in velocity template

问题

I am writing velocity templates for my liferay theme and I am wondering, whether it is possible to create a new object inside the velocity template.

The reason is that in liferay there is no contextTool registered in the context and I really want to be able to inspect the variables that are present in the template at a given time. There is a cool macro for this, but unfortunately it uses the contexttool.

I'd like to do something like:

#set($contextTool = new ContextTool())

Another solution would be java code that is provided with the liferay theme that is able to add stuff in the template context. But I don't know how this would work either... ;-)

回答1:

try with

#set($contextTool = $portal.getClass().forName("full.package.ContextTool").newInstance())

EDIT

IF I understood you than this should give you what you want

#set($ve = $serviceLocator.findService("com.liferay.portal.kernel.velocity.VelocityEngine"))
#set($wvc = $ve.getWrappedStandardToolsContext().getWrappedVelocityContext())

#set($cVE = $portal.getClass().forName("org.apache.velocity.app.VelocityEngine"))
#set($cHSREQ = $portal.getClass().forName("javax.servlet.http.HttpServletRequest"))
#set($cHSRES = $portal.getClass().forName("javax.servlet.http.HttpServletResponse"))
#set($cSC = $portal.getClass().forName("javax.servlet.ServletContext"))
#set($cCC = $portal.getClass().forName("org.apache.velocity.tools.view.context.ChainedContext"))
#set($cVEI = $portal.getClass().forName("com.liferay.portal.velocity.VelocityEngineImpl"))
#set($cC = $portal.getClass().forName("org.apache.velocity.context.Context"))
#set($cVEU = $portal.getClass().forName("com.liferay.portal.kernel.velocity.VelocityEngineUtil"))

#set($ve = $cVEU.getMethod("getVelocityEngine").invoke(null))

#set($fVE = $cVEI.getDeclaredField("_velocityEngine"))
$fVE.setAccessible(true)

#set($cc = $cCC.getConstructor($cC, $cVE, $cHSREQ, $cHSRES, $cSC).newInstance($wvc, $fVE.get($ve), $request, $response, $request.getSession().getServletContext()))

#set($contextTool = $portal.getClass().forName("org.apache.velocity.tools.view.tools.ContextTool").newInstance())

$contextTool.init($cc)

After that you can use, for example

$contextTool.getKeys()

If this is not what you need, let me know ...

来源：https://stackoverflow.com/questions/9826547/create-object-in-velocity-template