Variables are not coming up null during Postman call

Setting up an Java Postman call assigning values to the variables but its shows null.

        @PostMapping("/caStudents/student")
    public String generateSignedValue(@RequestBody StudentRequest studentRequest) throws Exception  
        String signedValue=studentService.getSignedValue(studentRequest);
        return signedValue;

My Pojo Student Class

      public class StudentRequest {
      String user;
      Long duration ;
      public String getPublicKey() {
        return publicKey;
    }

    public void setPublicKey(String publicKey) {
        this.publicKey = publicKey;
    }

    public String getUser() {
        return user;
    }

    public void setUser(String user) {
        this.user = user;
    }

    public Long getDuration() {
        return duration;
    }

    public void setDuration(Long duration) {
        this.duration = duration;
    }

Postman Request

{"studentRequest":[{"user":"admin","duration":19336}]}

Answer

your request body should be like this:

{"user":"admin","duration":19336}

because you are getting StudentRequest as RequestBody and it means you should send StudentRequest internal properties not containing StudentRequest it self in request , second problem is that your RequestBody contains singular object not array .