[FIXED] How do return value from lambda function via jdbcTemplate?

Issue

public List<User> getAll(){

        jdbcTemplate.query(query, rs -> {
            Map<Integer, User> userMap= new HashMap<>();

            while (rs.next()) {
                // adding elements

            }
            System.out.println(userMap.values()); // shows me correct result
            return userMap.values(); // not returning
        });
        return null;
    }

This method returning me null and ignoring return inside lambda function. How I can receive data which I got inside the lambda?

Solution

jdbcTemplate.query will return whatever you returned on the lambda function, in this case. Look at the documentation here.

So you could do:

public List<User> getAll(){
    return jdbcTemplate.query(query, rs -> {
        Map<Integer, User> userMap= new HashMap<>();
        while (rs.next()) {
            // adding elements
        }
        return userMap.values();
    });
}

Answered By - Mateus Bandeira