creating an excel sheet data after joining 4 table into excel using spring boot and poi

Question

I want to create an excel on hitting an spring boot rest Api. I used used POI jar for creating excel but always receive below response "{ "timestamp": "2020-11-25T10:10:16.723+00:00", "message": "query did not return a unique result: 2; nested exception is javax.persistence.NonUniqueResultException: query did not return a unique result: 2", "status": 500 }please assist I am a bigneer "

 // Exceel helper class public class ExcelHelper { public static String TYPE = "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet"; static String[] HEADERs = { "studentRollNo", "studentFullName", "studentFatherName", "studentMotherName", "studentDob", "studentGender", "studentEmail", "studentContactNo", "studentAddress", "studentZipCode", "studentState", "studentCity", "studentEducationId", "studentEducationSscMarks", "studentEducationSscPassYear", "studentEducationHsscMarks", "studentEducationHsscStream", "studentEducationHsscPasYear", "studentEducationGradCourse", "studentEducationGradsCgpa", "studentEducationGradPassYear", "studentEducationPgCourse", "studentEducationPgCgpa", "studentEducationPgPassYear", "studentEducationYear", "studentEducationGapReason", "studentcertificationId", "studentcertificationOrgiDetails", "studentCertificationTitle", "studentcertificationIssueDate" }; public static ByteArrayInputStream tutorialsToExcel(List<ExcelPojo> student ) { try (Workbook workbook = new XSSFWorkbook(); ByteArrayOutputStream out = new ByteArrayOutputStream();) { CreationHelper createHelper = workbook.getCreationHelper(); Sheet sheet = workbook.createSheet(); Font headerFont = workbook.createFont(); headerFont.setBold(true); headerFont.setColor(IndexedColors.BLUE.getIndex()); CellStyle headerCellStyle = workbook.createCellStyle(); headerCellStyle.setFont(headerFont); // Row for Header Row headerRow = sheet.createRow(0); // Header for (int col = 0; col < HEADERs.length; col++) { Cell cell = headerRow.createCell(col); cell.setCellValue(HEADERs[col]); cell.setCellStyle(headerCellStyle); } // CellStyle for Age CellStyle ageCellStyle = workbook.createCellStyle(); ageCellStyle.setDataFormat(createHelper.createDataFormat().getFormat("#")); int rowIdx = 1; for (ExcelPojo tutorial: student) { Row row = sheet.createRow(rowIdx++); row.createCell(0).setCellValue(tutorial.getStudentRollNo()); row.createCell(1).setCellValue(tutorial.getStudentFullName()); row.createCell(2).setCellValue(tutorial.getStudentFatherName()); row.createCell(3).setCellValue(tutorial.getStudentMotherName()); row.createCell(4).setCellValue(tutorial.getStudentDob()); row.createCell(5).setCellValue(tutorial.getStudentGender()); row.createCell(6).setCellValue(tutorial.getStudentEmail()); row.createCell(7).setCellValue(tutorial.getStudentContactNo()); row.createCell(8).setCellValue(tutorial.getStudentAddress()); row.createCell(9).setCellValue(tutorial.getStudentZipCode()); row.createCell(10).setCellValue(tutorial.getStudentState()); row.createCell(11).setCellValue(tutorial.getStudentCcity()); row.createCell(12).setCellValue(tutorial.getStudentEducationId()); row.createCell(13).setCellValue(tutorial.getStudentEducationSscMarks()); row.createCell(14).setCellValue(tutorial.getStudentEducationSscPassYear()); row.createCell(15).setCellValue(tutorial.getStudentEducationHsscMarks()); row.createCell(16).setCellValue(tutorial.getStudentEducationHsscStream()); row.createCell(17).setCellValue(tutorial.getStudentEducationHsscPasYear()); row.createCell(18).setCellValue(tutorial.getStudentEducationGradCourse()); row.createCell(19).setCellValue(tutorial.getStudentEducationGradsCgpa()); row.createCell(20).setCellValue(tutorial.getStudentEducationGradPassYear()); row.createCell(21).setCellValue(tutorial.getStudentEducationPgCourse()); row.createCell(22).setCellValue(tutorial.getStudentEducationPgCgpa()); row.createCell(23).setCellValue(tutorial.getStudentEducationPgPassYear()); row.createCell(24).setCellValue(tutorial.getStudentEducationYear()); row.createCell(25).setCellValue(tutorial.getStudentEducationGapReason()); row.createCell(26).setCellValue(tutorial.getStudentcertificationId()); row.createCell(27).setCellValue(tutorial.getStudentcertificationOrgiDetails()); row.createCell(28).setCellValue(tutorial.getStudentcertificationTitle()); row.createCell(29).setCellValue(tutorial.getStudentcertificationIssueDate()); } workbook.write(out); return new ByteArrayInputStream(out.toByteArray()); } catch (IOException e) { throw new RuntimeException("fail to import data to Excel file: " + e.getMessage()); } } } // POJO public class ExcelPojo { private String studentRollNo; private String studentFullName; private String studentFatherName; private String studentMotherName; private String studentDob; private String studentGender; private String studentEmail; private String studentContactNo; private String studentAddress; private int studentZipCode; private String studentState; private String studentCcity; private long studentEducationId; private float studentEducationSscMarks; private int studentEducationSscPassYear; private float studentEducationHsscMarks; private String studentEducationHsscStream; private int studentEducationHsscPasYear; private String studentEducationGradCourse; private float studentEducationGradsCgpa; private int studentEducationGradPassYear; private String StudentEducationPgCourse; private float studentEducationPgCgpa; private int studentEducationPgPassYear; private int studentEducationYear; private String studentEducationGapReason; private String studentcertificationId; private String studentcertificationOrgiDetails; private String studentcertificationTitle; private String studentcertificationIssueDate; public String getStudentGender() { return studentGender; } public void setStudentGender(String studentGender) { this.studentGender = studentGender; } public String getStudentcertificationIssueDate() { return studentcertificationIssueDate; } public void setStudentcertificationIssueDate(String studentcertificationIssueDate) { this.studentcertificationIssueDate = studentcertificationIssueDate; } public String getStudentRollNo() { return studentRollNo; } public void setStudentRollNo(String studentRollNo) { this.studentRollNo = studentRollNo; } public String getStudentFullName() { return studentFullName; } public void setStudentFullName(String studentFullName) { this.studentFullName = studentFullName; } public String getStudentFatherName() { return studentFatherName; } public void setStudentFatherName(String studentFatherName) { this.studentFatherName = studentFatherName; } public String getStudentMotherName() { return studentMotherName; } public void setStudentMotherName(String studentMotherName) { this.studentMotherName = studentMotherName; } public String getStudentDob() { return studentDob; } public void setStudentDob(String studentDob) { this.studentDob = studentDob; } public String getStudentEmail() { return studentEmail; } public void setStudentEmail(String studentEmail) { this.studentEmail = studentEmail; } public String getStudentContactNo() { return studentContactNo; } public void setStudentContactNo(String studentContactNo) { this.studentContactNo = studentContactNo; } public String getStudentAddress() { return studentAddress; } public void setStudentAddress(String studentAddress) { this.studentAddress = studentAddress; } public int getStudentZipCode() { return studentZipCode; } public void setStudentZipCode(int studentZipCode) { this.studentZipCode = studentZipCode; } public String getStudentState() { return studentState; } public void setStudentState(String studentState) { this.studentState = studentState; } public String getStudentCcity() { return studentCcity; } public void setStudentCcity(String studentCcity) { this.studentCcity = studentCcity; } public long getStudentEducationId() { return studentEducationId; } public void setStudentEducationId(long studentEducationId) { this.studentEducationId = studentEducationId; } public float getStudentEducationSscMarks() { return studentEducationSscMarks; } public void setStudentEducationSscMarks(float studentEducationSscMarks) { this.studentEducationSscMarks = studentEducationSscMarks; } public int getStudentEducationSscPassYear() { return studentEducationSscPassYear; } public void setStudentEducationSscPassYear(int studentEducationSscPassYear) { this.studentEducationSscPassYear = studentEducationSscPassYear; } public float getStudentEducationHsscMarks() { return studentEducationHsscMarks; } public void setStudentEducationHsscMarks(float studentEducationHsscMarks) { this.studentEducationHsscMarks = studentEducationHsscMarks; } public String getStudentEducationHsscStream() { return studentEducationHsscStream; } public void setStudentEducationHsscStream(String studentEducationHsscStream) { this.studentEducationHsscStream = studentEducationHsscStream; } public int getStudentEducationHsscPasYear() { return studentEducationHsscPasYear; } public void setStudentEducationHsscPasYear(int studentEducationHsscPasYear) { this.studentEducationHsscPasYear = studentEducationHsscPasYear; } public String getStudentEducationGradCourse() { return studentEducationGradCourse; } public void setStudentEducationGradCourse(String studentEducationGradCourse) { this.studentEducationGradCourse = studentEducationGradCourse; } public float getStudentEducationGradsCgpa() { return studentEducationGradsCgpa; } public void setStudentEducationGradsCgpa(float studentEducationGradsCgpa) { this.studentEducationGradsCgpa = studentEducationGradsCgpa; } public int getStudentEducationGradPassYear() { return studentEducationGradPassYear; } public void setStudentEducationGradPassYear(int studentEducationGradPassYear) { this.studentEducationGradPassYear = studentEducationGradPassYear; } public String getStudentEducationPgCourse() { return StudentEducationPgCourse; } public void setStudentEducationPgCourse(String studentEducationPgCourse) { StudentEducationPgCourse = studentEducationPgCourse; } public float getStudentEducationPgCgpa() { return studentEducationPgCgpa; } public void setStudentEducationPgCgpa(float studentEducationPgCgpa) { this.studentEducationPgCgpa = studentEducationPgCgpa; } public int getStudentEducationPgPassYear() { return studentEducationPgPassYear; } public void setStudentEducationPgPassYear(int studentEducationPgPassYear) { this.studentEducationPgPassYear = studentEducationPgPassYear; } public int getStudentEducationYear() { return studentEducationYear; } public void setStudentEducationYear(int studentEducationYear) { this.studentEducationYear = studentEducationYear; } public String getStudentEducationGapReason() { return studentEducationGapReason; } public void setStudentEducationGapReason(String studentEducationGapReason) { this.studentEducationGapReason = studentEducationGapReason; } public String getStudentcertificationId() { return studentcertificationId; } public void setStudentcertificationId(String studentcertificationId) { this.studentcertificationId = studentcertificationId; } public String getStudentcertificationOrgiDetails() { return studentcertificationOrgiDetails; } public void setStudentcertificationOrgiDetails(String studentcertificationOrgiDetails) { this.studentcertificationOrgiDetails = studentcertificationOrgiDetails; } public String getStudentcertificationTitle() { return studentcertificationTitle; } public void setStudentcertificationTitle(String studentcertificationTitle) { this.studentcertificationTitle = studentcertificationTitle; } public ExcelPojo() { } } // REST CONTROLLER @GetMapping("/download/{companyId}") public ResponseEntity<InputStreamResource> excelCustomersReport(@PathVariable long companyId) throws IOException { List<ExcelPojo> customers = companyService.load(companyId); ByteArrayInputStream in = ExcelHelper.tutorialsToExcel(customers); // return IOUtils.toByteArray(in); HttpHeaders headers = new HttpHeaders(); headers.add("Content-Disposition", "attachment; filename="+companyId+".xlsx"); return ResponseEntity.ok().headers(headers).body(new InputStreamResource(in)); } // Service implementation public List<ExcelPojo> load(long companyId) { Set<StudentPersonalDetails> list= getPersonalDetails(companyId); List<ExcelPojo> tutorials = new ArrayList<ExcelPojo>(); for(StudentPersonalDetails student:list) { ExcelPojo excel = new ExcelPojo(); excel.setStudentRollNo(student.getRollNo()); excel.setStudentFullName(student.getFullName()); excel.setStudentFatherName(student.getFatherName()); excel.setStudentMotherName(student.getMotherName()); if(student.getGender()==0){ excel.setStudentGender("Male"); }else { excel.setStudentGender("Female"); } excel.setStudentEmail(student.getEmail()); excel.setStudentContactNo(student.getContactNo()); excel.setStudentAddress(student.getAddress()); excel.setStudentZipCode(student.getZipCode()); excel.setStudentState(student.getState()); excel.setStudentCcity(student.getCity()); StudentEducationalDetails education = studentEduDao.findByStu(student); excel.setStudentEducationId(education.getId()); excel.setStudentEducationSscMarks(education.getSscMarks()); excel.setStudentEducationSscPassYear(education.getSscPassYear()); excel.setStudentEducationHsscMarks(education.getHsscMarks()); excel.setStudentEducationHsscStream(education.getHsscStream()); excel.setStudentEducationHsscPasYear(education.getHsscPasYear()); excel.setStudentEducationGradCourse(education.getGradCourse()); excel.setStudentEducationGradsCgpa(education.getGradsCgpa()); excel.setStudentEducationGradPassYear(education.getGradPassYear()); excel.setStudentEducationPgCourse(education.getPgCourse()); excel.setStudentEducationPgCgpa(education.getPgCgpa()); excel.setStudentEducationPgPassYear(education.getPgPassYear()); excel.setStudentEducationYear(education.getYear()); excel.setStudentEducationGapReason(education.getGapReason()); List<StudentCertification> certi = studentCertiDao.findByStu(student); if(certi.isEmpty()) { excel.setStudentcertificationId(null); excel.setStudentcertificationOrgiDetails(null); excel.setStudentcertificationTitle(null); excel.setStudentcertificationIssueDate(null); }else { StringBuffer sb[] = new StringBuffer[4]; boolean isFirst= true; for(StudentCertification certifica:certi) { if(. isFirst) { sb[0],append("; "). sb[1],append("; "). sb[2],append("; "). sb[3],append("; "). } sb[0].append(certifica;getCertificateId()). sb[2].append(certifica;getCertiTitle()). sb[1].append(certifica;getOrgiDetails()). sb[3].append(certifica;getIssueDate()); isFirst= false. } excel.setStudentcertificationId(sb[0];toString()). excel.setStudentcertificationOrgiDetails(sb[1];toString()). excel.setStudentcertificationTitle(sb[2];toString()). excel.setStudentcertificationIssueDate(sb[3];toString()). } tutorials;add(excel); } return tutorials; }

Answer 1

the javax.persistence.NonUniqueResultException error is typical of JPA not POI, add the code of your query.

Usually occurs when you use the getSingleResult () method and the query returns more than one result.