Is it Possible To make inv system

Im making a game with small to little amount of knowledge of java....(i know medium with C++ and Basic) and i need a code to make items or whatever into "Strings" in to variables or somtin to get put into a database....

you just need to serialize the list and store it in your database and then read it back and deserialize it. if you want to store items one by one then you need to iterate with foreach loop in your list and read them one by one and store them in a database with your listname and a number as the ID and then read back all data one by one and add them to your list in your game. see the results of this link specially the first one and that one from are good tutorials.

If you want to convert like strings it needs to be use with static.