• 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
  • Paul Clapham
  • Tim Cooke
  • Jeanne Boyarsky
  • Liutauras Vilda
Sheriffs:
  • Frank Carver
  • Henry Wong
  • Ron McLeod
Saloon Keepers:
  • Tim Moores
  • Frits Walraven
  • Tim Holloway
  • Stephan van Hulst
  • Carey Brown
Bartenders:
  • Al Hobbs
  • Piet Souris
  • Himai Minh

Singleton two or more instances

 
Ranch Hand
Posts: 423
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
Hi, The following is asked me several times during the interview
Question : Can we have singleton with 2 instances or 3 instances or more ? How to achieve that ?
My Answer : It cannot be more than 1 instance.
But interviewers are never happy with my answer even though I gave them the Singleton code. Please let me know how to get it. Please post code which helps me a alot.
 
Sheriff
Posts: 22683
128
Eclipse IDE Spring VI Editor Chrome Java Windows
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
How does singleton allows the flexibility to create more objects if the situation changes.
 
lowercase baba
Posts: 13073
67
Chrome Java Linux
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
Start a second JVM...
 
Saloon Keeper
Posts: 14293
321
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
Personally I've always thought of the Singleton pattern as one that generally limits the amount of instances created, but not necessarily to a single instance. The name is misleading, but the general case makes more sense for a pattern.
 
Bartender
Posts: 4568
9
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator

fred rosenberger wrote:Start a second JVM...


Or just use a second class loader?

It could be that they're thinking about distributed applications...in which case unless you're doing something clever there's nothing to stop the separate components each creating an instance.
 
With a little knowledge, a cast iron skillet is non-stick and lasts a lifetime.
reply
    Bookmark Topic Watch Topic
  • New Topic