Christmas is coming soon! To thank for the support from all our dear customers, Christmas promotional activity is going on in JavaCardOS online store. For more activities details, please check this post.

Static class variables in javacard applet

JavaCard Applet Development Related Questions and Answers.
Posts: 10
Joined: Tue Jan 26, 2016 11:08 pm
Points :119

Static class variables in javacard applet

Post by Elisadl » Tue Jan 26, 2016 11:14 pm

Hi folks!
I have some doubts about static class variables in javacard applet.

Q1: Why should I never use static class variables in java card applets or to use it very carefully ?
Q2: Why does the Static variables are stored in heap and what are the issues in using them?

Hope someone clarify my doubts. Thanks!

User avatar
Posts: 630
Joined: Thu May 21, 2015 4:05 am
Points :3027

Re: Static class variables in javacard applet

Post by UNKNwYSHSA » Thu Jan 28, 2016 10:21 pm

1 The applet instance which create one static object can't be deleted (You should set the static object to null before delete the applet instance);
2 You should make sure the static object is null or not before use it.
1 The static object is allocated by the new statement, so it is located in heap. The data memory space can be located in heap or COR/COD;
2 You can use it when applet instances use one common object.
sense and simplicity

Posts: 5
Joined: Thu May 17, 2018 11:04 am
Points :40

Re: Static class variables in javacard applet

Post by WhiteRabbit » Fri May 18, 2018 4:27 am

The static class variables are very useful for sharing data to across the object instance. Even to share the data among applets or packages.

Post Reply Previous topicNext topic

Who is online

Users browsing this forum: Bing [Bot], Google [Bot], illbreakitIS and 3 guests

JavaCard OS : Disclaimer