Spring Boot在內(nèi)部通過集成hibernate-validation實現(xiàn)了JSR-349驗證規(guī)范接口，我們可以在MVC模式中對DTO進行靈活的校驗,代碼看起來也會更簡潔、更優(yōu)雅.
參考地址:https://docs.jboss.org/hibernate/stable/validator/reference/en-US/pdf/hibernate_validator_reference.pdf

常用注解列表

maven依賴

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-validation</artifactId>
        </dependency>
       <!--Jackson,用于前端傳過來的json字符串,對其序列號和反序列化-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-json</artifactId>
        </dependency>

controller控制層

package com.example.demo.controller;


import com.alibaba.fastjson.JSONObject;
import com.example.demo.model.Result;
import com.example.demo.model.Student;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RestController;

import javax.validation.Valid;


@RestController
public class ValidationItemException {

    @PostMapping(value = "/validation/save")
    public Result saveStudentPage(@Valid @RequestBody Student student) {
        return new Result(200, "", JSONObject.toJSON(student).toString());
    }

    @PostMapping(value = "/validation/save2")
    public Student saveStudentPage2(@Valid @RequestBody Student student) {
        return student;
    }
}

DTO實體層(Student)

1.錯誤信息統(tǒng)一管理

我們也可以把錯誤信息message定制化到配置文件message.properties里面統(tǒng)一管理

2.@Valid和@Validated的區(qū)別

@Valid是javax.validation里的 @Validated是@Valid 的一次封裝，是Spring提供的校驗機制使用。@Validated 提供分組功能,但是在校驗項比較多的情況下,本人不是很推薦分組校驗,因為在開發(fā)中容易出錯.

package com.example.demo.model;

import com.fasterxml.jackson.annotation.JsonFormat;
import org.hibernate.validator.constraints.Range;

import javax.validation.constraints.Future;
import javax.validation.constraints.NotEmpty;
import javax.validation.constraints.Size;
import java.time.LocalDateTime;

public class Student {

    @Range(min=15,max=65,message = "年齡必須在15歲到65歲")
    private int age;

    @Size(min=2, max=30)
    private String name;

    @NotEmpty(message = "自定義錯誤信息,score不能為空!")
    private String score;

    @Future(message = "生效時間必須大于當前時間")
    @JsonFormat(pattern = "yyyy-MM-dd HH:mm:ss")
    private LocalDateTime createTime;


    public LocalDateTime getCreateTime() {
        return createTime;
    }

    public void setCreateTime(LocalDateTime createTime) {
        this.createTime = createTime;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getScore() {
        return score;
    }

    public void setScore(String score) {
        this.score = score;
    }


    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    @Override
    public String toString() {
        return "Student{" +
                "age=" + age +
                ", name='" + name + '\'' +
                ", score='" + score + '\'' +
                '}';
    }
}

DTO實體層(Result)

package com.example.demo.model;

public class Result implements java.io.Serializable{

    private int code;
    private String msg;
    private Object data;

    public int getCode() {
        return code;
    }

    public void setCode(int code) {
        this.code = code;
    }

    public String getMsg() {
        return msg;
    }

    public void setMsg(String msg) {
        this.msg = msg;
    }

    public Object getData() {
        return data;
    }

    public void setData(Object data) {
        this.data = data;
    }

    @Override
    public String toString() {
        return "Result{" +
                "code=" + code +
                ", msg='" + msg + '\'' +
                ", data=" + data +
                '}';
    }
}

全局異常捕獲

package com.example.demo.Hanlder;

import com.example.demo.model.Result;
import org.springframework.http.HttpStatus;
import org.springframework.validation.ObjectError;
import org.springframework.web.bind.MethodArgumentNotValidException;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.RestControllerAdvice;

import java.util.List;
import java.util.stream.Collectors;

@RestControllerAdvice
public class BindExceptionHandler {
    /**
     * 全局異常捕捉處理
     *
     * @param ex
     * @return
     */
    @ExceptionHandler(MethodArgumentNotValidException.class)
    public Result handleBindException(MethodArgumentNotValidException ex) {

// 同樣是獲取BindingResult對象，然后獲取其中的錯誤信息
        // 如果前面開啟了fail_fast，事實上這里只會有一個信息
        //如果沒有，則可能又多個
        List<String> errorInformation = ex.getBindingResult().getAllErrors()
                .stream()
                .map(ObjectError::getDefaultMessage)
                .collect(Collectors.toList());
        return new Result(HttpStatus.BAD_REQUEST.value(),errorInformation.toString(),null) ;
    }
}

測試結(jié)果

image.png