Postgres: Calling function from spring jdbc template

What is the correct way to call postgres function with custom types from the spring StoredProcedure?

Say I have a function and custom types as defined:

CREATE OR REPLACE FUNCTION addUser(user IN O_USER) RETURNS VOID
AS
$$
BEGIN

end;
$$ language plpgsql;

CREATE TYPE O_USER AS (
  id NUMERIC,
  name VARCHAR(50)
);

While calling it from Spring I am converting user object to String as shown below:

public class AddUserProcedurePostgres extends StoredProcedure {

    public AddUserProcedurePostgres(DataSource dataSource) {
        super(dataSource, "addUser");
        setFunction(true);

        declareParameter(new SqlParameter("i_User", Types.OTHER, "O_USER"));

        compile();
    }

    public void execute(SessionContext sessionContext, Dashboard dashboard) {

        Map<String, Object> input = new HashMap<>();
        input.put("i_User", "(1,Vishal)");

        execute(input);
    }

}

Now my questions are:

1. Is it the right way to create a String corresponding to the object and then pass it? Or is there any better way?

2. Suppose I need to add array of other custom type in the existing O_USER, then how the string need to be formatted?

CREATE TYPE O_USER AS (
  id NUMERIC,
  name VARCHAR(50)
  addresses O_ADDRESS[]
);