How to use List in another function - spring

Question

--------------------------------------Table 1--------------------------------------
#Entity
#Table(name = "student_details")
public class StudentDetails {
#Id
private Long studentId;
private String firstName;
private String lastName;
private String fatherName;
// with getter and setters
}
-------------------------------------Table 2---------------------------------
#Entity
#Table(name = "student_marks")
public class StudentMarks {
#Id
private Long studentId;
private int Maths;
private int English;
private int Computer;
// with getter and setters
}
------------------------------------class which combine these two table------------------
public class StudentReportData {
#Id
private Long studentId;
private String studentName
private String fatherName;
private int Maths;
private int English;
private int Computer;
//with getter and setters
}
-----------------------------------Service Class---------------------------
#Service
public class StudentService {
public ApiResponce<List<StudentReportData>> getStudentData() {
ApiResponce<List<StudentReportData>> responce = new ApiResponce();
Status status = new Status();
status setSuccess(true);
try {
List<StudentReportData> studentList = new ArrayList<StudentReportData>();
List<StudentMarks> findAll = studentMarksRepository.findAll();
for(StudentMarks sm : findAll) {
StudentReportData studentData = new StudentReportData();
BeanUtils.copyProperties(sm, studentData);
StudentDetails studentDetailsData = studentDetailsRepository.findByStudentId(sm.getStudentId());
studentData.setStudentName(studentDetailsData.getFirstName()+" "+studentDetailsData.getLastName());
studentList.add(studentData);
}
response.setData(studentList);
} catch (Exception ex) {
ex.printStackTrace();
ErrorData errorData = new ErrorData();
errorData.setErrorCode("ERR003");
errorData.setErrorMessage("Internal Server Error");
status.setErrorData(errorData);
status.setSuccess(false);
}
response.setStatus(status);
return response;
}
public ByteArrayInputStream load() {
ByteArrayInputStream in = ExcelHelper.studentreportToExcel(studentList);
return in;
}
}
I want to pass this studentList as an argument to the function studentReportToExcel from the function load. How can I get that List Inside the load function.

Answer 1

Add it as a class attribute, something like:
#Service
public class StudentService {
private List<StudentReportData> studentList; // class attribute to add
public ApiResponce<List<StudentReportData>> getStudentData() {
ApiResponce<List<StudentReportData>> responce = new ApiResponce();
Status status = new Status();
status setSuccess(true);
try {
studentList = new ArrayList<StudentReportData>(); // line changed
List<StudentMarks> findAll = studentMarksRepository.findAll();
for(StudentMarks sm : findAll) {
StudentReportData studentData = new StudentReportData();
BeanUtils.copyProperties(sm, studentData);
StudentDetails studentDetailsData = studentDetailsRepository.findByStudentId(sm.getStudentId());
studentData.setStudentName(studentDetailsData.getFirstName()+" "+studentDetailsData.getLastName());
studentList.add(studentData);
}
response.setData(studentList);
} catch (Exception ex) {
ex.printStackTrace();
ErrorData errorData = new ErrorData();
errorData.setErrorCode("ERR003");
errorData.setErrorMessage("Internal Server Error");
status.setErrorData(errorData);
status.setSuccess(false);
}
response.setStatus(status);
return response;
}
public ByteArrayInputStream load() {
ByteArrayInputStream in = ExcelHelper.studentreportToExcel(studentList);
return in;
}
}