This week's book giveaways are in the Scala and Android forums.
We're giving away four copies each of Machine Learning Systems: Designs that scale and Xamarin in Action: Creating native cross-platform mobile apps and have the authors on-line!
See this thread and this one for details.
Win a copy of Machine Learning Systems: Designs that scale this week in the Scala forum
or Xamarin in Action: Creating native cross-platform mobile apps in the Android forum!
  • Post Reply Bookmark Topic Watch Topic
  • New Topic

Extracting A Value From Hashmap  RSS feed

 
Ranch Hand
Posts: 115
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
I have my HashMap set up to accept a film title as the key and a JavaBean encapsulating information about the film as a value. I need to get the JavaBean out of the HashMap in order to format and present the information in the JavBean. I get stuck at the following line FilmBean film = container.get(it.next());. This is because the get() method only retrives the key.
 
Ranch Hand
Posts: 225
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
I can be sure because you don't post your FilmContainer code, but wouldn't it be better with :

FilmBean film = container.get(it.next());

Note : HashMap.get(aKey) returns the object associated with the key, not the key...

And are all the cast statements ((int)film.getLength()...) necessary
 
henri henri
Ranch Hand
Posts: 115
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
The FilmContainer is a simple class extended from HashMap
 
henri henri
Ranch Hand
Posts: 115
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
This compiles but does not retrieve each Javabean.



 
author and iconoclast
Sheriff
Posts: 24219
40
Chrome Eclipse IDE Mac OS X
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Right. It retrieves all the keys, because you're iterating over the keySet(). If you want to iterate over all the values, you can use container.values() in place of container.keySet() in the above.

You need to slow down a little, take a deep breath, and pay attention more.
 
henri henri
Ranch Hand
Posts: 115
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Thank you so much for your help Mr. Friedman-Hill. It works!! The data in my FilmBeans is printed out. It worked with this code:

 
Seb Mathe
Ranch Hand
Posts: 225
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
If container is a Map,


you must retrieve values, too.
 
This cake looks terrible, but it tastes great! Now take a bite out of this tiny ad:
Rocket Oven Kickstarter - from the trailboss
https://coderanch.com/t/695773/Rocket-Oven-Kickstarter-trailboss
  • Post Reply Bookmark Topic Watch Topic
  • New Topic
Boost this thread!