SpringBoot 参数校验

---

一、添加依赖

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-validation</artifactId>
</dependency>

二、实体类中添加校验规则注解

package cn.bounter.validation.entity;

import lombok.Data;
import lombok.experimental.Accessors;

import javax.validation.constraints.Min;
import javax.validation.constraints.NotBlank;

@Data
@Accessors(chain = true)
public class Bounter {

    @NotBlank
    private String name;

    @Min(18)
    private Integer age;

}

JSR-303常用注解如下：

//空检查

@NotNull          对象不为null

@NotBlank         字符串不为null且不是”“ 

@NotEmpty         集合不为null且不为空

 

//长度检查

@Size(min = 1, max = 10)     字符串长度或集合大小

@Length                      字符串长度   

 

//数值检查

@Min(1)

@Max(10)
@Range(min = 1, max = 10)

 

//其他

@Email

@AssertTrue

@AssertFalse 

 

 

三、开启校验（开启后请求时会自动触发校验，校验失败抛出异常）

package cn.bounter.validation.controller;

import cn.bounter.validation.common.ResponseData;
import cn.bounter.validation.entity.Bounter;
import org.springframework.validation.annotation.Validated;
import org.springframework.web.bind.annotation.*;

@RestController
@RequestMapping("/api/bounter")
public class BounterController {

    @PostMapping
    public ResponseData<?> post(@Validated Bounter bounter) {
        return ResponseData.ok(bounter);
    }

    @PostMapping("/json")
    public ResponseData<?> postJson(@Validated @RequestBody Bounter bounter) {
        return ResponseData.ok(bounter);
    }

    @GetMapping
    public ResponseData<?> get(@Validated Bounter bounter) {
        return ResponseData.ok(bounter);
    }

}

四、统一处理校验异常，并返回错误提示

package cn.bounter.validation.common;

import org.springframework.validation.BindException;
import org.springframework.validation.FieldError;
import org.springframework.web.bind.MethodArgumentNotValidException;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.RestControllerAdvice;

import java.util.stream.Collectors;

@RestControllerAdvice
public class AppExceptionHandler {

    /**
     * 处理不带任何注解的参数绑定校验异常
     * @param e
     * @return
     */
    @ExceptionHandler(BindException.class)
    public ResponseData<?> handleBingException(BindException e) {
        String errorMsg = e.getBindingResult().getAllErrors()
                .stream()
                .map(objectError -> ((FieldError)objectError).getField() + ((FieldError)objectError).getDefaultMessage())
                .collect(Collectors.joining(","));
        //"errorMsg": "name不能为空,age最小不能小于18"
        return new ResponseData<>().fail(errorMsg);
    }

    /**
     * 处理 @RequestBody参数校验异常
     * @param e
     * @return
     */
    @ExceptionHandler(MethodArgumentNotValidException.class)
    public ResponseData<?> handleMethodArgumentNotValidException(MethodArgumentNotValidException e) {
        String errorMsg = e.getBindingResult().getAllErrors()
                .stream()
                .map(objectError -> ((FieldError)objectError).getField() + ((FieldError)objectError).getDefaultMessage())
                .collect(Collectors.joining(","));
        //"errorMsg": "name不能为空,age最小不能小于18"
        return new ResponseData<>().fail(errorMsg);
    }

}

五、如需要手动触发校验，则可使用下面的方式

package cn.bounter.validation;

import cn.bounter.validation.entity.Bounter;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringRunner;

import javax.validation.ConstraintViolation;
import javax.validation.Validator;
import java.util.Set;

@RunWith(SpringRunner.class)
@SpringBootTest
public class BounterValidationApplicationTests {

    //参数校验器
    @Autowired
    private Validator validator;

    /**
     * 测试手动触发校验
     */
    @Test
    public void testValidation() {
        Bounter bounter = new Bounter().setName("").setAge(17);

        Set<ConstraintViolation<Bounter>> violationSet = validator.validate(bounter);
        violationSet.forEach(violation -> {
            //name不能为空
            //age最小不能小于18
            System.out.println(violation.getPropertyPath() + violation.getMessage());
        });
    }

}

这就是全部的步骤了，是不是觉得的挺简单的哉！那就赶快自己动手试试吧！

Github传送门：https://github.com/13babybear/bounter-validation