JAVA

copy from vim to clipboard

y is for yanking within vim
Use "+ to copy to the system clipboard 
Thus use "+y instead of y

Likewise you can paste using "+ to get text from the system clipboard
i.e. "+p instead of just p

vim yank to clipboard

"*  <- this will set the register for system (ubuntu and macos) 

While on Visual Mode select desired text then type "*y
For paste go to Visual Mode and type "*p