how to read .csv file as key value pair?

username 1 abc password 1 123 username 2 pqr password 2 456 username 3 xyz password 3 789

how to read .csv file values like .properties file, means whenever we give key name its should display value correspondence to that key in selenium?

when I enter username1 it should display abc. similarly,s for password1 it should display 123 in java