null 체크 대신 isPresent() 사용
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@Test
public void nameTest() throws Exception {
Map<Integer, String> members = new HashMap<>();
members.put(1, "jooyong");
members.put(2, "devhak");
members.put(3, "cjr");
Optional<String> stringOptional = Optional.fromNullable(members.get(4));
if (stringOptional.isPresent()) {
System.out.println("member is " + stringOptional);
} else {
System.out.println("member is empty"); // member is empty
}
}
null인 경우 기본값을 세팅하면 더 편리하다.
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@Test
public void orTest() throws Exception {
Map<Integer, String> members = new HashMap<>();
members.put(1, "jooyong");
members.put(2, "devhak");
members.put(3, "cjr");
Optional<String> stringOptional = Optional.fromNullable(members.get(4));
System.out.println("member is " + stringOptional.or("empty"));
}