Java Lambda Expressions cannot have their own state, like other classes can. The only way a Java lambda expression can have any kind of internal state is by referencing a variable declared outside the lamdba expression. This video explains how that is done, and the rules for doing so.
This video is part of a playlist on Java lambda expressions which you can see here:
• Java Lambda Expressions
I also have a text version of the Java lambda expression playlist here:
http://tutorials.jenkov.com/java/lamb...