介绍

在项目的过程中，对于参数的校验是必须的，如果参数比较少的话我们可以直接通过代码进行校验，但是数据较大时再用这个方法就比较笨重了，接下来就该我们的主角Validation闪亮登场了

pom.xml

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

        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

实际上在这里数据校验都是调用的javax.validation，spring-boot-starter-web中也包含了hibernate-validator，有兴趣的可以去翻翻文档

User.java

package com.priv.gabriel.entity;

import lombok.Data;
import org.hibernate.validator.constraints.Length;

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


/**
 * Created with Intellij IDEA.
 *
 * @Author: Gabriel
 * @Date: 2018-10-23
 * @Description:
 */
@Data
public class User {

    @NotBlank(message = "name不允许为空")
    @Length(min = 2,max = 10,message = "你的长度不对劲呀")
    private String name;
    @NotNull(message = "进入未成年人入内！")
    @Min(18)
    private int age;
    @NotBlank(message = "拒绝黑户")
    private String address;

}

接下来只需要在Controller层中使用@valid进行校验就可以了

package com.priv.gabriel.controller;

import com.priv.gabriel.entity.User;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import javax.validation.Valid;

/**
 * Created with Intellij IDEA.
 *
 * @Author: Gabriel
 * @Date: 2018-10-23
 * @Description:
 */
@RestController
@RequestMapping("/user")
public class UserController {

    @RequestMapping("/check")
    public String check(@Valid User user){
        return "检测完毕！没有问题";
    }
}

用Rest Client工具简单检测一下

结果当然是...

{
    "timestamp": "2018-10-23T09:01:45.159+0000",
    "status": 400,
    "error": "Bad Request",
    "errors": [{
        "codes": ["Length.user.name", "Length.name", "Length.java.lang.String", "Length"],
        "arguments": [{
            "codes": ["user.name", "name"],
            "arguments": null,
            "defaultMessage": "name",
            "code": "name"
        }, 10, 2],
        "defaultMessage": "你的长度不对劲呀",
        "objectName": "user",
        "field": "name",
        "rejectedValue": "",
        "bindingFailure": false,
        "code": "Length"
    }, {
        "codes": ["Min.user.age", "Min.age", "Min.int", "Min"],
        "arguments": [{
            "codes": ["user.age", "age"],
            "arguments": null,
            "defaultMessage": "age",
            "code": "age"
        }, 18],
        "defaultMessage": "最小不能小于18",
        "objectName": "user",
        "field": "age",
        "rejectedValue": 17,
        "bindingFailure": false,
        "code": "Min"
    }, {
        "codes": ["NotBlank.user.address", "NotBlank.address", "NotBlank.java.lang.String", "NotBlank"],
        "arguments": [{
            "codes": ["user.address", "address"],
            "arguments": null,
            "defaultMessage": "address",
            "code": "address"
        }],
        "defaultMessage": "拒绝黑户",
        "objectName": "user",
        "field": "address",
        "rejectedValue": "",
        "bindingFailure": false,
        "code": "NotBlank"
    }, {
        "codes": ["NotBlank.user.name", "NotBlank.name", "NotBlank.java.lang.String", "NotBlank"],
        "arguments": [{
            "codes": ["user.name", "name"],
            "arguments": null,
            "defaultMessage": "name",
            "code": "name"
        }],
        "defaultMessage": "name不允许为空",
        "objectName": "user",
        "field": "name",
        "rejectedValue": "",
        "bindingFailure": false,
        "code": "NotBlank"
    }],
    "message": "Validation failed for object='user'. Error count: 4",
    "path": "/user/check"
}

好了，到这里可以看到我们的设置已经生效了，关于数据校验你get到了吗？
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