Mock Unit Test Case For Spring jdbc template for RowMapper - spring

Question

I am trying to test with Junit for my StudentRowmapper class, I am a bit new for Unit Test and also Mock test, I have asked smilar question before, but I could not figure out how to mock Datetime.of object. When I run my test; DateTimes throws null pointer exception
StudentGroupList below;
#Getter
#Setter
public class StudentGroupList {
private String studentId;
private LocalDateTime studentDate();
}
StudentGroupListRowMapper below;
public class StudentGroupListRowMapper implements RowMapper<StudentGroupList> {
#Override
public StudentGroupList mapRow(Resultset rs, int rowNum) throws SQLException {
StudentGroupList studentGroupList = new StudentGroupList();
studentGroupList.setStudentId(rs.getString("student_id"));
studentGroupList.setStudentDate(rs.getTimestamp("student_date").toLocalDateTime());
return studentGroupList;
}
}
My Unit Test below;
private static int rowNum = 2;
private StudentGroupListRowMapper mapper;
private ResultSet resultSet;
private StudentGroupList studentGroupList;
#Before
public void setUp() {
studentGroupList = new StudentGroupList();
mapper = new StudentGroupListRowMapper();
resultSet = mock(ResultSet.class);
}
#Test
public void testmapRow() throws SQLException {
when(resultSet.getString("student_id")).thenReturn("sutdent-id-1");
when(resultSet.getTimeStamp("student_date").toLocalDateTime()).thenReturn(LocalDateTime.of(2001,3,17,2,10)));
studentGroupList mapper.mapRow(resultSet, rowNum);
assertEquals(studentGroupList .getStudentId(), "sutdent-id-1");
assertEquals(studentGroupList .getStudentDate, LocalDateTime.of(2001,3,17,2,10));
}

Answer 1

private static int rowNum = 2;
#InjectMocks
private StudentGroupListRowMapper mapper;
#Mock
private ResultSet resultSet;
#Mock
private StudentGroupList studentGroupList;
#Before
public void setUp() {
MockitoAnnotations.initMocks(this);
studentGroupList = new StudentGroupList();
mapper = new StudentGroupListRowMapper();
resultSet = createResultSet();
}
createResultSet(){
resultSet = new ResultSet();
resultSet.setStudentId(111);
resultSet.setStudentId(LocalDateTime.of(2001,3,17,2,10));
}
#Test
public void testmapRow() throws SQLException {
studentGroupList = mapper.mapRow(resultSet, rowNum);
asserThat(studentGroupList.getStudentId()).isEqualTo(110);
asserThat(studentGroupList.getStudentId()).isEqualTo(LocalDateTime.of(2001,3,17,2,10));
}
I suggest you convert String student id to an int or parse the string. I just used an integer. From what I could gather, this is my solution for you. Hope you could understand the structure of the test. There are more ways to do this