java - jdbcTemplate batchUpdate 抛出 java.lang.ClassCastException : java. util.ArrayList 无法转换

Question

我尝试使用jdbcTemplate.batchUpdate向亲属表添加多个数据:

我尝试从学生表中选择maxid，并在插入查询中使用它作为ID。

这是我的代码:

List<Relatives> relatives=student.getRelatives();
String sql3="Select Id,Name from Student where Id=(select Max(Id) from student)";
final Student student1= (Student) jdbcTemplate.query(sql3, new UserMapper5());  
String sql4 = " INSERT INTO Relatives (StudentId,RelativeId,YearId,ClassId,SectionId,RelationshipId,IsDeleted,CreatedBy,CreatedDate) "+
                 " Values(?,?,?,?,?,?,?,?,GETDATE())";
int[][] updateCounts = jdbcTemplate.batchUpdate(sql4, relatives, relatives.size(),
    new ParameterizedPreparedStatementSetter<Relatives>() {
        public void setValues(PreparedStatement ps, Relatives relative) throws SQLException {
            ps.setInt(1, student1.getId());
            ps.setString(2, relative.getStudent().getName());
            ps.setInt(3, relative.getStudent().getYear().getId());
            ps.setInt(4, relative.getStudent().getClasss().getId());
            ps.setInt(5, relative.getStudent().getSection().getId());
            ps.setInt(6, relative.getRelationship().getId());
            ps.setInt(7, 0);
            ps.setInt(8,123);
        }
    }
); 

当我尝试将多个数据插入亲属表时，出现以下错误:

java.lang.ClassCastException: java.util.ArrayList cannot be cast to com.cloudnexus.spring.model.Student

Answer 1

jdbcTemplate.query with RowMapper 返回一个列表，然后如果不为空则获取学生:

List<Student> studentList = jdbcTemplate.query(...
if (!studentList.isEmpty()){ 
   Student student1 = studentList.get(0);

Returns: the result List, containing mapped objects