Spring boot进行参数校验的方法实例详解

class RequestForm {
  @Size(min = 1, max = 5)
  private String name;
  public String getName() {
    return name;
  }
  public void setName(String name) {
    this.name = name;
  }
}

  @ResponseBody
  @GetMapping(value = "bean")
  public String validate(@Valid RequestForm request) {
    System.out.println(request.getName());
    return "OK";
  }

@Target({ ElementType.FIELD, ElementType.PARAMETER })
@Retention(RetentionPolicy.RUNTIME)
@Constraint(validatedBy = NameConstraintValidator.class)
@interface NameConstraint {
  String[] allowedValues();
  Class<?>[] groups() default {};
  Class<? extends Payload>[] payload() default {};
  String message();
}

class NameConstraintValidator implements ConstraintValidator<NameConstraint, String> {
  private String[] validValues;
  @Override
  public void initialize(NameConstraint constraintAnnotation) {
    validValues = constraintAnnotation.allowedValues();
  }
  @Override
  public boolean isValid(String value, ConstraintValidatorContext context) {
    for (String s : this.validValues) {
      if (s.equals(value)) {
        return true;
      }
    }
    return false;
  }
}

class RequestFormWithCustomConstraint {
  @NameConstraint(allowedValues = { "bar", "foo" }, message = "只允许bar,foo")
  private String name;
  public String getName() {
    return name;
  }
  public void setName(String name) {
    this.name = name;
  }
}

@Controller
@Validated
@RequestMapping(value = "validator")
public class ParameterValidatorDemoController {
  @ResponseBody
  @GetMapping(value = "simple")
  public String validateParameter(@Size(min = 1, max = 5) String name) {
    System.out.println(name);
    return "OK";
  }
}