Collectives™ on Stack Overflow
Find centralized, trusted content and collaborate around the technologies you use most.
Learn more about Collectives
Teams
Q&A for work
Connect and share knowledge within a single location that is structured and easy to search.
Learn more about Teams
passing id value to controller gives an error " Failed to convert the value of type 'java.lang.String' to required type 'int'".
but when I print System.out.println(studentService.findById(id)) it give a output in terminal as
Optional[Student{id=1, firstName='Abhishek', lastName='Shukla', branch='CS', year=4, mobileNumber='9876543210'}]
I already tried to pass the id as a string and convert string to int by using Integr.parseInt(id) in the controller but it throws an error as
" Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is java.lang.NumberFormatException: For input string: "{id}"] with root cause "
<h1>Student Place</h1>
<form name="myForm" action="/student/{id}" >
<table border="1">
<tbody>
<td>Student ID :</td>
<td><input type="text" name="id" size="10" /> </td>
</tbody>
</table>
<input type="submit" value="submit" name="submit" /><br>
<input type="reset" value="Rest" name="reset" />
</form>
@GetMapping(value = "/students")
public String index(ModelMap modelMap){
modelMap.put("students" , studentService.findAll());
return "index" ;
@GetMapping(value = "/student/{id}")
public String data(@PathVariable("id") int id , ModelMap modelMap){
modelMap.put("students" , studentService.findById(id)) ;
System.out.println(studentService.findById(id));
return "studentbyid" ;
@GetMapping(value = "/student")
public String databyid(){
return "student" ;
@Transactional
@Service("studentService")
public class StudentServiceImpl implements StudentService {
@Autowired
private StudentRepository studentRepository ;
@Override
public Iterable<Student> findAll() {
return studentRepository.findAll();
public Optional<Student> findById(int id) {
return studentRepository.findById(id);
public Student(int id, String firstName, String lastName, String branch, int year, String mobileNumber) {
this.id = id;
this.firstName = firstName;
this.lastName = lastName;
this.branch = branch;
this.year = year;
this.mobileNumber = mobileNumber;
public int getId() {
return id;
public void setId(int id) {
this.id = id;
public String getFirstName() {
return firstName;
public void setFirstName(String firstName) {
this.firstName = firstName;
public String getLastName() {
return lastName;
public void setLastName(String lastName) {
this.lastName = lastName;
public String getBranch() {
return branch;
public void setBranch(String branch) {
this.branch = branch;
public int getYear() {
return year;
public void setYear(int year) {
this.year = year;
public String getMobileNumber() {
return mobileNumber;
public void setMobileNumber(String mobileNumber) {
this.mobileNumber = mobileNumber;
@Override
public String toString() {
return "Student{" +
"id=" + id +
", firstName='" + firstName + '\'' +
", lastName='" + lastName + '\'' +
", branch='" + branch + '\'' +
", year=" + year +
", mobileNumber='" + mobileNumber + '\'' +
Whitelabel Error Page
This application has no explicit mapping for /error, so you are seeing this as a fallback.
There was an unexpected error (type=Bad Request, status=400).
Failed to convert value of type 'java.lang.String' to required type 'int'; nested exception is java.lang.NumberFormatException: For input string: "{id}"
So, as the error message shows, you are literally sending a request to
/student/{id}
instead of, let's say,
/student/1234
.
Since apparently, the form has an input field where the user must enter the ID, the ID will be sent as a request parameter, not as a path variable, so the path of your controller method and of your action should simply be
/students
and it should take the ID as a request parameter:
@GetMapping(value = "/student")
public String data(@RequestParam("id") int id, ModelMap modelMap)
Try using @RequestParam instead of @PathVariable as you're already sending <input name = "id">, so
Like, that's a parameter you're already sending, so you should fetch it as a param, not as Path Variable.
Once you do so, keep the url as /students
instead of /students/{id}
Should work then.
–
Thanks for contributing an answer to Stack Overflow!
- Please be sure to answer the question. Provide details and share your research!
But avoid …
- Asking for help, clarification, or responding to other answers.
- Making statements based on opinion; back them up with references or personal experience.
To learn more, see our tips on writing great answers.
