Solved

create from a list a key value map

Posted on 2008-10-20
8
1,132 Views
Last Modified: 2013-11-23
Hi experts!

I have a class who returns me a List of options. The problem is that I would like to convert it somehow with a help of a method to a value - key object.
I am using this list in a JSP site and I would like to save at the very end the key of the selected option

Thanks
0
Comment
Question by:dlcnet
8 Comments
 
LVL 20

Expert Comment

by:chaitu chaitu
ID: 22757167
Instead of List use Hashmap ;Please post sample code
0
 

Author Comment

by:dlcnet
ID: 22757258
@chaituu

I have a hashmap already and a list too. My problem is how to link those too that the list values corresponds to the hashmap values and the result of the method is the key of the choosed value form the list
0
 
LVL 27

Expert Comment

by:rrz
ID: 22763679
Your question isn't very clear. Please show us your code.
0
Best Practices: Disaster Recovery Testing

Besides backup, any IT division should have a disaster recovery plan. You will find a few tips below relating to the development of such a plan and to what issues one should pay special attention in the course of backup planning.

 
LVL 5

Expert Comment

by:muktajindal
ID: 22765800
Post your code or try giving some concrete example.
0
 

Author Comment

by:dlcnet
ID: 22766076
@all:

The code is bellow. I am using on the website the List method to generate a drop down list. I am interested to convert the option that the user converted into the Integer Key of the HashMap and the method is returning me, for example when user selected Bla Bla -> 1


public List listAll() {
   List options = new ArrayList<String>();
   options.add("Bla Bla");
   options.add("Bla Bla 2");
}
 
public Map<Integer, String> getOptions() {
   Map<Integer, String> optionsConvertor = new HashMap<Integer, String>();
   optionConvertor.put(1, getText("Bla Bla"));
   optionConvertor.put(2, getText("Bla Bla 2"));
}

Open in new window

0
 
LVL 5

Expert Comment

by:muktajindal
ID: 22766149
As I understand, you already have this List and this Hashmap, and you want to get "1" when user selects "Bla Bla", "2" when user selects "Bla Bla 2".

You can achieve this by inverting the type specification in your map. Use Map<String, Integer> instead of Map<Integer, String> and then use optionsConvertor.get(key) to get the desired value.
0
 

Author Comment

by:dlcnet
ID: 22766365
@muktajindal

yes, you understood corectly. Can you please please provide me a code who will do this?  I mean a method who gets as parameters the List and the Map and returns me the ineteger value of the key

Thanks!
0
 
LVL 5

Accepted Solution

by:
muktajindal earned 500 total points
ID: 22783500
As I mentioned, you need to use Map<String, Integer> instead of Map<Integer, String>.
Refer to the attached code snippet. Using this, you can use it as follows :
optionsConvertor.get("Bla Bla") will return you 1.
optionsConvertor.get("Bla Bla 2") will return you 2.

public Map<String, Integer> getOptions() {
   Map<String, Integer> optionsConvertor = new HashMap<String, Integer>();
   optionsConvertor.put("Bla Bla", 1);
   optionsConvertor.put("Bla Bla 2", 2);
   return optionsConvertor;
}

Open in new window

0

Featured Post

Problems using Powershell and Active Directory?

Managing Active Directory does not always have to be complicated.  If you are spending more time trying instead of doing, then it's time to look at something else. For nearly 20 years, AD admins around the world have used one tool for day-to-day AD management: Hyena. Discover why

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

Title # Comments Views Activity
split53 challenge 7 96
GUI builder for Eclipse? 8 35
even odd program using while loop 3 40
How to convert String matching to regex in java 4 33
For customizing the look of your lightweight component and making it look lucid like it was made of glass. Or: how to make your component more Apple-ish ;) This tip assumes your component to be of rectangular shape and completely opaque. (COD…
Introduction This article is the last of three articles that explain why and how the Experts Exchange QA Team does test automation for our web site. This article covers our test design approach and then goes through a simple test case example, how …
Video by: Michael
Viewers learn about how to reduce the potential repetitiveness of coding in main by developing methods to perform specific tasks for their program. Additionally, objects are introduced for the purpose of learning how to call methods in Java. Define …
Viewers learn about the scanner class in this video and are introduced to receiving user input for their programs. Additionally, objects, conditional statements, and loops are used to help reinforce the concepts. Introduce Scanner class: Importing…

772 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question