java - TestNG, Selenium How to share object among multiple Classes -

i executing test cases using selenium + testng. test cases spread across multiple classes. want use same copy of webdriver every class. (i dont want login every time , other operations option of invoking separate browser each class gone). solve problem, right using inheritance static webdriver object. while using selenium grid parallel mode, not work uses same object. can please show me way in which, can share object multiple class or create different instance of static on each "test" (its like, running separate java program each test).

currently using static reference of webdriver object across various classes/tests. so, there single instance of driver modifying static resources in code. when go grid, create different driver instance each node. these drivers going run in parallel , accessing shared resources(static variables, etc.) simultaneously changing , overriding changes made other driver instances cause issues.

write code such resources not shared(min. use of static). try passing driver instance methods ensure required driver executing piece of code.