How to check that List<Long> contains a value?

Question

I have list List<Long> list, that contains: [160774, 7212775] and Long id = 7212775. I need to check if the list contains an element with value of id. How to do that? Unfortunately list.contains(id) returns false in my case.

I'm using it that way:

@RequestMapping("/case/{id}")
public String openCase(@PathVariable("id") Long id) {

    log.debug(caseDAO.findAllCasesId());    // [160774, 7212775]
    log.debug(id); // 7212775

    if(caseDAO.findAllCasesId().contains(id)) {
        return "case";
    } else {
        return "404";
    }
}

Piece of DAO (Hibernate, but native sql here):

public List<Long> findAllCasesId() {
    String sql = "select id from cases";
    SQLQuery query = getSession().createSQLQuery(sql);
    return query.list();
}

---

SOLVED

The problem was with caseDAO.findAllCasesId(), that return list of Object, not list of Long. I corrected this by:

SQLQuery query = getSession().createSQLQuery(sql).addScalar("id", Hibernate.LONG);

Big thanks to: Nayuki Minase

Answer 1

When autoboxing, you need to make sure you postfix the literal with an L i.e. Long id = 7212775L for this to work.

Answer 2

Running the code below on eclipse helios:

public static void main(String[] args) {
    List<Long> list = new ArrayList<Long>();
    list.add(160774L);
    list.add(7212775L);
    System.out.println(list.contains(7212775L);
}

Output:

true

What you're doing wrong is

System.out.println(list.contains(7212775));

The problem is that your list takes Long objects and you are searching for a literal.