[java] Spring MVC: Complex object as GET @RequestParam

Since the question on how to set fields mandatory pops up under each post, I wrote a small example on how to set fields as required:

public class ExampleDTO {
    @NotNull
    private String mandatoryParam;

    private String optionalParam;
    
    @DateTimeFormat(iso = ISO.DATE) //accept Dates only in YYYY-MM-DD
    @NotNull
    private LocalDate testDate;

    public String getMandatoryParam() {
        return mandatoryParam;
    }
    public void setMandatoryParam(String mandatoryParam) {
        this.mandatoryParam = mandatoryParam;
    }
    public String getOptionalParam() {
        return optionalParam;
    }
    public void setOptionalParam(String optionalParam) {
        this.optionalParam = optionalParam;
    }
    public LocalDate getTestDate() {
        return testDate;
    }
    public void setTestDate(LocalDate testDate) {
        this.testDate = testDate;
    }
}

//Add this to your rest controller class
@RequestMapping(value = "/test", method = RequestMethod.GET)
public String testComplexObject (@Valid ExampleDTO e){
    System.out.println(e.getMandatoryParam() + " " + e.getTestDate());
    return "Does this work?";
}