如何模拟 ResultSet 在 JUnit 和 Mockito 中不返回 null

Question

我试图在使用日历的 DAO 中测试一个方法。这是我到目前为止的测试：

@Test
public void testGetElectionInfo() throws SQLException {
    adminDao.getElectionInfo(1);
    verify(mockConn, times(1)).prepareStatement(anyString());
    verify(mockPreparedStmnt, times(1)).setInt(anyInt(), anyInt());
    verify(mockPreparedStmnt, times(1)).executeQuery();
    verify(mockResultSet, times(2)).next();
    verify(mockResultSet, times(1)).getString("name");
    verify(mockResultSet, times(1)).getTimestamp("startDate");
    verify(mockResultSet, times(1)).getTimestamp("endDate");
}

这是DAO方法：

public ElectionInfo getElectionInfo(int electionId) {
    ElectionInfo electionInfo = new ElectionInfo();
    try {
        con = sqlConnection.getConnection();

        stmt = con.prepareStatement(NamedQueries.GET_ELECTION_INFO);
        stmt.setInt(1, electionId);
        rs = stmt.executeQuery();

        if(rs.next()) {
            String name = rs.getString("name");
            Timestamp startDate = rs.getTimestamp("startDate");
            Timestamp endDate = rs.getTimestamp("endDate");

            Calendar startCalender = Calendar.getInstance();
            startCalender.setTime(startDate);

            Calendar endCalender = Calendar.getInstance();
            endCalender.setTime(endDate);

            electionInfo.setName(name);
            electionInfo.setStartDate(startCalender);
            electionInfo.setEndDate(endCalender);
        }

        return electionInfo;
    } catch (SQLException e) {
        LOGGER.log(Level.SEVERE, "Couldn't get the election info of the planned elections.", e);
    } finally{
        closeConnection();
    }
    return electionInfo;
}

当我运行测试时，它给了我一个

java.lang.NullPointerException
    at java.util.Calendar.setTime

我该如何解决这个问题？您能否发布解决此问题的代码？这对我有很大帮助！

提前致谢！

Answer 1

线， verify(mockResultSet, times(1)).getTimestamp("startDate"); 模拟调用但不要求模拟库返回时间戳值，因此库返回 null 导致它抛出 NPE。尝试更改为，

verify(mockResultSet, times(1)).getTimestamp("startDate").thenReturn(new Timestamp(0)); 以及其他方法也是如此。