• Post Reply Bookmark Topic Watch Topic
  • New Topic
programming forums Java Mobile Certification Databases Caching Books Engineering Micro Controllers OS Languages Paradigms IDEs Build Tools Frameworks Application Servers Open Source This Site Careers Other Pie Elite all forums
this forum made possible by our volunteer staff, including ...
Marshals:
  • Campbell Ritchie
  • Jeanne Boyarsky
  • Ron McLeod
  • Paul Clapham
  • Liutauras Vilda
Sheriffs:
  • paul wheaton
  • Rob Spoor
  • Devaka Cooray
Saloon Keepers:
  • Stephan van Hulst
  • Tim Holloway
  • Carey Brown
  • Frits Walraven
  • Tim Moores
Bartenders:
  • Mikalai Zaikin

Struts 2 - Understanding the working between OGNL and params interceptor

 
Ranch Hand
Posts: 39
Eclipse IDE Firefox Browser Java
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
I am new to struts 2. I am studying it from the book Struts2 In Action. I am having difficulty in understanding some concepts in OGNL which are as follows-

1)We know that params interceptor moves the data from the request parameters to the action object in ValueStack. Now while reading, I came upon a line that says- "The tricky part of the job is mapping the name of the parameter to an actual property on the ValueStack. This is where OGNL comes in. The params interceptor interprets the request parameter name as an OGNL expression to locate the correct destination property on the ValueStack".

Ques1)Here, what does "interprets" mean? Is it that params interceptor translates the request parameter into some OGNL expression and then OGNL expression provides mapping to the properties in ValueStack OR does it mean something else?

2) When result start its rendering process, the Struts 2 tags retrieve data from the ValueStack by referencing specific values with OGNL expressions.

Ques 2)So the tags take OGNL expressions, but how is the data being moved? Earlier, params interceptor was the one that moved the data but now there is no params interceptor. So how is the data being moved?
 
Consider Paul's rocket mass heater.
reply
    Bookmark Topic Watch Topic
  • New Topic