Spring Boot 2 中的参数校验 spring-boot-starter-validation/Hibernate Validator
在springboot中常用的用于参数校验的注解如下：
@AssertFalse 所注解的元素必须是Boolean类型，且值为false
@AssertTrue 所注解的元素必须是Boolean类型，且值为true
@DecimalMax 所注解的元素必须是数字，且值小于等于给定的值
@DecimalMin 所注解的元素必须是数字，且值大于等于给定的值
@Digits 所注解的元素必须是数字，且值必须是指定的位数
@Future 所注解的元素必须是将来某个日期
@Max 所注解的元素必须是数字，且值小于等于给定的值
@Min 所注解的元素必须是数字，且值小于等于给定的值
@Range 所注解的元素需在指定范围区间内
@NotNull 所注解的元素值不能为null
@NotBlank 所注解的元素值有内容
@Null 所注解的元素值为null
@Past 所注解的元素必须是某个过去的日期
@PastOrPresent 所注解的元素必须是过去某个或现在日期
@Pattern 所注解的元素必须满足给定的正则表达式
@Size 所注解的元素必须是String、集合或数组，且长度大小需保证在给定范围之内
@Email 所注解的元素需满足Email格式
一、添加依赖
org.springframework.boot
spring-boot-starter-validation
这个starter依赖的是Hibernate Validator。
二、实体类参数校验
（一）实体类上加上注解
import lombok.Data;
import javax.validation.constraints.*;
import java.io.Serializable;
/**
* @author chushiyan
* @email Y2h1c2hpeWFuMDQxNUAxNjMuY29t(base64)
* @description
*/
@Data
public class User implements Serializable {
private String id;
@NotNull(message = "姓名不能为空")
@Size(min = 1, max = 20, message = "姓名长度必须在1-20之间")
private String name;
@Min(value = 10, message = "年龄必须大于10")
@Max(value = 150, message = "年龄必须小于150")
private Integer age;
@Email(message = "邮箱格式不正确")
private String email;
}
（二）Controller中加上注解
在controller中使用@Valid 或者@Validated 注解校验
import com.chushiyan.validation_tutorial.entity.Result;
import com.chushiyan.validation_tutorial.pojo.User;
import org.springframework.web.bind.annotation.*;
import javax.validation.Valid;
/**
* @author chushiyan
* @email Y2h1c2hpeWFuMDQxNUAxNjMuY29t(base64)
* @description
*/
@RestController
@RequestMapping("/user")
public class UserController {
@PostMapping
public Result test(@Valid @RequestBody User user){
System.out.println(user);
return new Result(true,200,"");
}
}
（三）测试
使用postman发送POST请求：http://localhost:10000/user
{
"age":120,
"email":"chushiyan"
}
控制台打印：
WARN 12476 --- [io-10000-exec-1] .w.s.m.s.DefaultHandlerExceptionResolver : Resolved [org.springframework.web.bind.MethodArgumentNotValidException: Validation failed for argument [0] in public com.chushiyan.validation_tutorial.entity.Result com.chushiyan.validation_tutorial.controller.UserController.test(com.chushiyan.validation_tutorial.pojo.User) with 2 errors: [Field error in object 'user' on field 'name': rejected value [null]; codes [NotNull.user.name,NotNull.name,NotNull.java.lang.String,NotNull]; arguments [org.springframework.context.support.DefaultMessageSourceResolvable: codes [user.name,name]; arguments []; default message [name]]; default message [姓名不能为空]] [Field error in object 'user' on field 'email': rejected value [chushiyan]; codes [Email.user.email,Email.email,Email.java.lang.String,Email]; arguments [org.springframework.context.support.DefaultMessageSourceResolvable: codes [user.email,email]; arguments []; default message [email],[Ljavax.validation.constraints.Pattern$Flag;@20195c7a,.*]; default message [邮箱格式不正确]] ]
响应的数据：
{
"timestamp": "2019-12-03T09:14:00.759+0000",
"status": 400,
"error": "Bad Request",
"errors": [
{
"codes": [
"NotNull.user.name",
"NotNull.name",
"NotNull.java.lang.String",
"NotNull"
],
"arguments": [
{
"codes": [
"user.name",
"name"
],
"arguments": null,
"defaultMessage": "name",
"code": "name"
}
],
"defaultMessage": "姓名不能为空",
"objectName": "user",
"field": "name",
"rejectedValue": null,
"bindingFailure": false,
"code": "NotNull"
},
{
"codes": [
"Email.user.email",
"Email.email",
"Email.java.lang.String",
"Email"
],
"arguments": [
{
"codes": [
"user.email",
"email"
],
"arguments": null,
"defaultMessage": "email",
"code": "email"
},
[],
{
"arguments": null,
"defaultMessage": ".*",
"codes": [
".*"
]
}
],
"defaultMessage": "邮箱格式不正确",
"objectName": "user",
"field": "email",
"rejectedValue": "chushiyan",
"bindingFailure": false,
"code": "Email"
}
],
"message": "Validation failed for object='user'. Error count: 2",
"trace": "org.springframework.web.bind.MethodArgumentNotValidException: Validation failed for argument [0] in public com.chushiyan.validation_tutorial.entity.Result com.chushiyan.validation_tutorial.controller.UserController.test(com.chushiyan.validation_tutorial.pojo.User) with 2 errors: [Field error in object 'user' on field 'name': rejected value [null]; codes [NotNull.user.name,NotNull.name,NotNull.java.lang.String,NotNull]; arguments [org.springframework.context.support.DefaultMessageSourceResolvable: codes [user.name,name]; arguments []; default message [name]]; default message [姓名不能为空]] [Field error in object 'user' on field 'email': rejected value [chushiyan]; codes [Email.user.email,Email.email,Email.java.lang.String,Email]; arguments [org.springframework.context.support.DefaultMessageSourceResolvable: codes [user.email,email]; arguments []; default message [email],[Ljavax.validation.constraints.Pattern$Flag;@20195c7a,.*]; default message [邮箱格式不正确]] \r\n\tat （博主进行了省略......）",
"path": "/user"
}
（四）全局处理异常
上面响应的错误肯定是不够友好的，所以需要进行异常处理。这里定义一个全局处理函数
import com.chushiyan.validation_tutorial.entity.Result;
import org.springframework.http.HttpStatus;
import org.springframework.validation.BindException;
import org.springframework.validation.ObjectError;
import org.springframework.web.bind.MethodArgumentNotValidException;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.ResponseStatus;
import org.springframework.web.bind.annotation.RestControllerAdvice;
import java.util.Date;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import java.util.stream.Collectors;
/**
* @author chushiyan
* @email Y2h1c2hpeWFuMDQxNUAxNjMuY29t(base64)
* @description
*/
@RestControllerAdvice
public class GlobalExceptionHandler {
/**
* 处理所有校验失败的异常（MethodArgumentNotValidException异常）
*
* @param ex
* @return
*/
@ExceptionHandler(value = MethodArgumentNotValidException.class)
// 设置响应状态码为400
@ResponseStatus(HttpStatus.BAD_REQUEST)
public Result handleBindGetException(MethodArgumentNotValidException ex) {
Map<String, Object> body = new LinkedHashMap<String, Object>();
body.put("timestamp", new Date());
// 获取所有异常
List<String> errors = ex.getBindingResult()
.getFieldErrors()
.stream()
.map(x -> x.getDefaultMessage())
.collect(Collectors.toList());
body.put("errors", errors);
return new Result(false, 20001, "提交的数据校验失败", body);
}
}
（五）再次测试
使用postman发送POST请求：http://localhost:10000/user
{
"age":120,
"email":"chushiyan"
}
响应的json数据：
{
"flag": false,
"code": 20001,
"message": "提交的数据校验失败",
"data": {
"timestamp": "2019-12-03T09:35:02.815+0000",
"errors": [
"邮箱格式不正确",
"姓名不能为空"
]
}
}
三、单个参数校验
(一）直接在参数前加上校验注解：
package com.chushiyan.validation_tutorial.controller;
import com.chushiyan.validation_tutorial.entity.Result;
import com.chushiyan.validation_tutorial.pojo.User;
import org.springframework.validation.annotation.Validated;
import org.springframework.web.bind.annotation.*;
import javax.validation.Valid;
import javax.validation.constraints.NotNull;
/**
* @author chushiyan
* @email Y2h1c2hpeWFuMDQxNUAxNjMuY29t(base64)
* @description
*/
@RestController
@RequestMapping("/user")
@Validated
public class UserController {
@GetMapping
public Result test2(@NotNull(message = "name不能为空") String name){
System.out.println(name);
return new Result(true,200,"");
}
}
注意：需要在类上添加@Validated注解，否则不会校验。
（二）全局处理函数
import com.chushiyan.validation_tutorial.entity.Result;
import org.springframework.http.HttpStatus;
import org.springframework.validation.BindException;
import org.springframework.validation.ObjectError;
import org.springframework.web.bind.MethodArgumentNotValidException;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.ResponseStatus;
import org.springframework.web.bind.annotation.RestControllerAdvice;
import javax.validation.ConstraintViolation;
import javax.validation.ConstraintViolationException;
import javax.validation.ValidationException;
import java.util.*;
import java.util.stream.Collectors;
/**
* @author chushiyan
* @email Y2h1c2hpeWFuMDQxNUAxNjMuY29t(base64)
* @description
*/
@RestControllerAdvice
public class GlobalExceptionHandler {
/**
* 处理所有参数校验时抛出的异常
*
* @param ex
* @return
*/
@ExceptionHandler(value = ValidationException.class)
public Result handleBindException(ValidationException ex) {
Map<String, Object> body = new LinkedHashMap<String, Object>();
body.put("timestamp", new Date());
// 获取所有异常
List<String> errors = new LinkedList<String>();
if(ex instanceof ConstraintViolationException){
ConstraintViolationException exs = (ConstraintViolationException) ex;
Set<ConstraintViolation<?>> violations = exs.getConstraintViolations();
for (ConstraintViolation<?> item : violations) {
errors.add(item.getMessage());
}
}
body.put("errors", errors);
return new Result(true, 20001, "提交的参数校验失败", body);
}
}
（二）测试
postman 测试http://localhost:10000/user GET
{
"flag": true,
"code": 20001,
"message": "提交的参数校验失败",
"data": {
"timestamp": "2019-12-03T09:58:45.212+0000",
"errors": [
"name不能为空"
]
}
}
四、参数校验分组
在实际开发中经常会遇到这种情况：添加用户时，id是由后端生成的，不需要校验id是否为空，但是修改用户时就需要校验id是否为空。如果在接收参数的User实体类的id属性上添加NotNull，显然无法实现。这时候就可以定义分组，在需要校验id的时候校验，不需要的时候不校验。
（一）定义表示组别的接口类
package com.chushiyan.validation_tutorial.validate;
public interface GroupA {
}
（二）在实体类的注解中标记id使用上面定义的组
给id属性添加分组：
package com.chushiyan.validation_tutorial.pojo;
import com.chushiyan.validation_tutorial.validate.GroupA;
import lombok.Data;
import javax.validation.constraints.*;
import java.io.Serializable;
/**
* @author chushiyan
* @email Y2h1c2hpeWFuMDQxNUAxNjMuY29t(base64)
* @description
*/
@Data
public class User implements Serializable {
@NotNull(groups = GroupA.class, message = "id不能为空")
private String id;
@NotNull(message = "姓名不能为空")
@Size(min = 1, max = 20, message = "姓名长度必须在1-20之间")
private String name;
@Min(value = 10, message = "年龄必须大于10")
@Max(value = 150, message = "年龄必须小于150")
private Integer age;
@Email(message = "邮箱格式不正确")
private String email;
}
（三）在controller中使用@Validated指定使用哪个组
@PostMapping
public Result add(@Validated @RequestBody User user) {
return new Result(true, 200, "增加用户成功");
}
@PutMapping("/update")
// 指定GroupA，这样就会校验id属性是否为空
// 注意：还得必须添加Default.class，否则不会执行其他的校验（如我们案例中的@Email）
public Result update(@Validated({GroupA.class, Default.class}) @RequestBody User user) {
return new Result(true, 200, "修改用户成功");
}
完整代码