Please help with these Java question

1. (5 points)Write code that opens a file named Number List.txt for writing, but does not erase the file's contents if it already exists. (Question 2 to 4:5points each, total 15 points) 2. (5 points)write code that does the following: opens a file named Nu uses a loop to write the numbers 1 through 100 to the file, and then doses the file. 3. (s points) write code that does the following: opens the NumberList.bxt file that was created by the code in Question 2, reads all of the numbers from the file and displays tem, and then closes the file