java spring Validator-优快云博客

本文介绍如何使用Spring Boot中的Validator接口进行表单验证。通过KmailPostForm类实例演示了如何实现验证逻辑，包括字段不能为空及数值范围检查等。同时展示了如何在控制器中集成验证器并处理验证失败的情况。

1. Validation using Spring’s Validator interface

Spring features a Validator interface that you can use to validate objects. The Validator interface works using an Errors object so that while validating, validators can report validation failures to the Errors object.

2. data object:

public class KmailPostForm {
    private Integer kid;

    public KmailPostForm() {
    }

    public Integer getKid() {

        return kid;
    }

    public void setKid(Integer kid) {
        this.kid = kid;
    }
}

3. validator:

import com.maduar.springbootdemo.form.KmailPostForm;
import org.springframework.validation.Errors;
import org.springframework.validation.ValidationUtils;
import org.springframework.validation.Validator;

public class KmailPostFormValidator implements Validator {
    @Override
    public boolean supports(Class<?> clazz) {
        return KmailPostForm.class.equals(clazz);
    }

    @Override
    public void validate(Object target, Errors errors) {
        ValidationUtils.rejectIfEmpty(errors, "kid", "kid.empty");
        KmailPostForm kmailPostForm = (KmailPostForm) target;
        if (kmailPostForm.getKid() == null) {
            errors.rejectValue("kid", "kid is null");
        } else if (kmailPostForm.getKid().intValue() < 0) {
            errors.rejectValue("kid", "kid < 0");
        }
    }
}

4. controller

@RestController
@RequestMapping(value = "/user")
public class UserController {

    @InitBinder
    public void initBinder(DataBinder dataBinder) {
        dataBinder.setValidator(new KmailPostFormValidator());
    }


    @PostMapping(value = "/helloPost/")
    public HttpEntity<?> helloPost(@Valid @RequestBody KmailPostForm kmailPostForm, BindingResult result) {

        if (result.hasErrors()) {
            return ResponseEntity.ok("error");
        }

        return ResponseEntity.ok("OK");
    }

}

a: springboot 版本 1.5.9.RELEASE

b: https://docs.spring.io/spring-framework/docs/current/spring-framework-reference/core.html#validation

转载于:https://www.cnblogs.com/maduar/p/9350061.html