Spring Validation 参数校验学习笔记

野性酷女 2022-11-25 13:16 175阅读 0赞

### Spring Validation 学习笔记 ###

*  基本用法
 *   *  注解校验
     *  控制器
 *  分组校验
 *   *  控制器
 *  校验顺序
 *  自定义校验
 *   *  自定义注解
     *  实现ConstraintValidator接口编写约束校验器
 *  代码方式校验
 *  快速失败
 *  踩坑
 *   *  Spring 2.3.0 起 \`web starters\` 不包含 \`Validation Starter\` 了
 *  参考资料

SpringBoot 已经整合了 Hibernate Validation。`Spring 2.3.0 起需要自己添加依赖。`  
验证本身比较好理解。主要是与全局异常配合这块，要根据自己项目实际情况来考虑。  
提醒：如果你在纠结某个字段要加两种校验规则，并且它们还冲突时，多加一个DTO试试

<table> 
 <thead> 
  <tr> 
   <th>区别</th> 
   <th>@Valid</th> 
   <th>@Validated</th> 
  </tr> 
 </thead> 
 <tbody> 
  <tr> 
   <td>提供者</td> 
   <td>JSR-303规范</td> 
   <td>Spring框架</td> 
  </tr> 
  <tr> 
   <td>支持分组</td> 
   <td>否</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>标注位置</td> 
   <td>METHOD, FIELD, CONSTRUCTOR, PARAMETER, TYPE_USE</td> 
   <td>TYPE, METHOD, PARAMETER</td> 
  </tr> 
  <tr> 
   <td>支持嵌套校验</td> 
   <td>是</td> 
   <td>否</td> 
  </tr> 
 </tbody> 
</table>

# 基本用法 #

## 注解校验 ##

注解说明 摘自：[锦成同学][Link 1]的[《这么写参数校验(validator)就不会被劝退了~》][validator]

<table> 
 <thead> 
  <tr> 
   <th align="left">验证注解</th> 
   <th align="left">验证的数据类型</th> 
   <th align="left">说明</th> 
  </tr> 
 </thead> 
 <tbody> 
  <tr> 
   <td align="left">@AssertFalse</td> 
   <td align="left">Boolean,boolean</td> 
   <td align="left">验证注解的元素值是false</td> 
  </tr> 
  <tr> 
   <td align="left">@AssertTrue</td> 
   <td align="left">Boolean,boolean</td> 
   <td align="left">验证注解的元素值是true</td> 
  </tr> 
  <tr> 
   <td align="left">@NotNull</td> 
   <td align="left">任意类型</td> 
   <td align="left">验证注解的元素值不是null</td> 
  </tr> 
  <tr> 
   <td align="left">@Null</td> 
   <td align="left">任意类型</td> 
   <td align="left">验证注解的元素值是null</td> 
  </tr> 
  <tr> 
   <td align="left">@Min(value=值)</td> 
   <td align="left">BigDecimal，BigInteger, byte,short, int, long，等任何Number或CharSequence（存储的是数字）子类型</td> 
   <td align="left">验证注解的元素值大于等于@Min指定的value值</td> 
  </tr> 
  <tr> 
   <td align="left">@Max（value=值）</td> 
   <td align="left">和@Min要求一样</td> 
   <td align="left">验证注解的元素值小于等于@Max指定的value值</td> 
  </tr> 
  <tr> 
   <td align="left">@DecimalMin(value=值)</td> 
   <td align="left">和@Min要求一样</td> 
   <td align="left">验证注解的元素值大于等于@ DecimalMin指定的value值</td> 
  </tr> 
  <tr> 
   <td align="left">@DecimalMax(value=值)</td> 
   <td align="left">和@Min要求一样</td> 
   <td align="left">验证注解的元素值小于等于@ DecimalMax指定的value值</td> 
  </tr> 
  <tr> 
   <td align="left">@Digits(integer=整数位数, fraction=小数位数)</td> 
   <td align="left">和@Min要求一样</td> 
   <td align="left">验证注解的元素值的整数位数和小数位数上限</td> 
  </tr> 
  <tr> 
   <td align="left">@Size(min=下限, max=上限)</td> 
   <td align="left">字符串、Collection、Map、数组等</td> 
   <td align="left">验证注解的元素值的在min和max（包含）指定区间之内，如字符长度、集合大小</td> 
  </tr> 
  <tr> 
   <td align="left">@Past</td> 
   <td align="left">java.util.Date,java.util.Calendar;Joda Time类库的日期类型</td> 
   <td align="left">验证注解的元素值（日期类型）比当前时间早</td> 
  </tr> 
  <tr> 
   <td align="left">@Future</td> 
   <td align="left">与@Past要求一样</td> 
   <td align="left">验证注解的元素值（日期类型）比当前时间晚</td> 
  </tr> 
  <tr> 
   <td align="left">@NotBlank</td> 
   <td align="left">CharSequence子类型</td> 
   <td align="left">验证注解的元素值不为空（不为null、去除首位空格后长度为0），不同于@NotEmpty，@NotBlank只应用于字符串且在比较时会去除字符串的首位空格</td> 
  </tr> 
  <tr> 
   <td align="left">@Length(min=下限, max=上限)</td> 
   <td align="left">CharSequence子类型</td> 
   <td align="left">验证注解的元素值长度在min和max区间内</td> 
  </tr> 
  <tr> 
   <td align="left">@NotEmpty</td> 
   <td align="left">CharSequence子类型、Collection、Map、数组</td> 
   <td align="left">验证注解的元素值不为null且不为空（字符串长度不为0、集合大小不为0）</td> 
  </tr> 
  <tr> 
   <td align="left">@Range(min=最小值, max=最大值)</td> 
   <td align="left">BigDecimal,BigInteger,CharSequence, byte, short, int, long等原子类型和包装类型</td> 
   <td align="left">验证注解的元素值在最小值和最大值之间</td> 
  </tr> 
  <tr> 
   <td align="left">@Email(regexp=正则表达式,flag=标志的模式)</td> 
   <td align="left">CharSequence子类型（如String）</td> 
   <td align="left">验证注解的元素值是Email，也可以通过regexp和flag指定自定义的email格式</td> 
  </tr> 
  <tr> 
   <td align="left">@Pattern(regexp=正则表达式,flag=标志的模式)</td> 
   <td align="left">String，任何CharSequence的子类型</td> 
   <td align="left">验证注解的元素值与指定的正则表达式匹配</td> 
  </tr> 
  <tr> 
   <td align="left">@Valid</td> 
   <td align="left">任何非原子类型</td> 
   <td align="left">指定递归验证关联的对象如用户对象中有个地址对象属性，如果想在验证用户对象时一起验证地址对象的话，在地址对象上加@Valid注解即可级联验证</td> 
  </tr> 
 </tbody> 
</table>

package jerry.demo.entity;
    
    import javax.validation.constraints.Max;
    import javax.validation.constraints.Min;
    import javax.validation.constraints.NotBlank;
    import javax.validation.constraints.Size;
    
    public class Player { 
    	@NotNull
    	private Long id;
    	
    	@NotBlank(message = "岂能无名？")
        @Size(max = 12, message = "名字最长12个字")
    	private String name;
    	
    	@Min(value = 18,message = "未成年人，禁止入内")
    	@Max(value = 200,message = "我一眼就看出你不是人！")
    	private Integer age;
    
    	// getter,setter 略
    }

## 控制器 ##

要校验的对象前添加注解：`@Valid`  
校验结果自动保存在：`BindingResult result`  
以下只是演示校验功能。真正使用场景中应该向上抛锅到`全局异常`中去处理。

@RestController
    public class WelcomeController { 
    
    	@RequestMapping("/")
    	public Map welcome(@Valid Player player, BindingResult result) { 
    		Map map = new HashMap();
    		 
    		String msg = "你好: " + player.getName();
    		int code = 200;
    		
    		if(result.hasErrors()){ 
    			ArrayList<String> errorMsg = new ArrayList<String>();
                for (ObjectError error : result.getAllErrors()) { 
                    errorMsg.add(error.getDefaultMessage());
                }            
                
                code = 400;
                msg = errorMsg.toString();
            }
    		
    		map.put("code", code);
    		map.put("msg", msg);
            return map;
    	}
    }

# 分组校验 #

同一个`DTO`可能在 `Add`和`Upd`两个接口中使用。

public class Player { 
    	@NotNull(groups = { Upd.class, Del.class}) /groups 多个值时用数组
    	private Long id;
    	
    	@NotBlank(message = "岂能无名？", groups = Add.class)
        @Size(max = 12, message = "名字最长12个字")
    	private String name;
    	
    	@Min(value = 18,message = "未成年人，禁止入内")
    	@Max(value = 200,message = "我一眼就看出你不是人！")
    	private Integer age;
    
    	// getter,setter 略
    }

## 控制器 ##

要校验的对象前添加注解：`@Validated` 支持分组功能

@RestController
    public class WelcomeController { 
    
    	@RequestMapping("/upd")
    	public Map welcome(@Validated(Upd.class) Player player, BindingResult result) { 
    		//。。。同上
    	}
    }

# 校验顺序 #

支持定义校验的先后顺序  
定义两个接口，用来分组

public interface A { }
    public interface B { }
    
    @GroupSequence({ A.class,B.class})  
    public interface GroupSeq { }

校验规则用接口分组

public class Player { 
    	@NotNull(groups = A.class)
    	private Long id;
    	
    	@NotBlank(message = "岂能无名？", groups = B.class)
        @Size(max = 12, message = "名字最长12个字")
    	private String name;
    	
    	@Min(value = 18,message = "未成年人，禁止入内")
    	@Max(value = 200,message = "我一眼就看出你不是人！")
    	private Integer age;
    
    	// getter,setter 略
    }

校验GroupSequence\`\`

@RestController
    public class WelcomeController { 
    
    	@RequestMapping("/upd")
    	public Map welcome(@Validated(GroupSeq.class) Player player, BindingResult result) { 
    		//。。。同上
    	}
    }

# 自定义校验 #

## 自定义注解 ##

`@MyValid` 验证小写英文字母

@Target({ METHOD, FIELD, ANNOTATION_TYPE, CONSTRUCTOR, PARAMETER})
    @Retention(RUNTIME)
    @Documented
    @Constraint(validatedBy = { MyValidator.class})
    public @interface MyValid { 
    
        // 默认错误消息
        String message() default "错误了";
    
        // 默认分组
        Class<?>[] groups() default { };
    
        // 默认负载
        Class<? extends Payload>[] payload() default { };
    }

## 实现ConstraintValidator接口编写约束校验器 ##

public class MyValidator implements ConstraintValidator<Player, String> { 
    
        private static final Pattern PATTERN = Pattern.compile("^[a-z]+$");
    
        @Override
        public boolean isValid(String value, ConstraintValidatorContext context) { 
            // 有值才校验
            if (value != null) { 
                Matcher matcher = PATTERN.matcher(value);
                return matcher.find();
            }
            return true;
        }
    }

# 代码方式校验 #

@Autowired
    private javax.validation.Validator validator;
    
    // 编程式校验
    @PostMapping("/saveWithCodingValidate")
    public Result saveWithCodingValidate(@RequestBody Player player ) { 
        Set<ConstraintViolation<Player>> validate = validator.validate(player, A.class);
        // validate 为空校验通过。否则未通过的信息都存在 validate
        if (!validate.isEmpty()) { 
        	ArrayList<Object> errorMsg = new ArrayList<Object>();
            for (ConstraintViolation<Player> vd: validate) { 
                errorMsg.add(vd);
            }
            return Result.fail(errorMsg.toString());
        }
        // 验证通过
        return Result.ok();
    }

# 快速失败 #

有时只要一个参数错了就不需要继续了，但默认规则会校验完全部参数才一起返回错误。这时我们可以开启`快速失败`。

@Bean
    public Validator validator() { 
        ValidatorFactory vf = Validation.byProvider(HibernateValidator.class)
                .configure()
                .failFast(true) // 快速失败开启
                .buildValidatorFactory();
        return vf.getValidator();
    }

# 踩坑 #

## Spring 2.3.0 起 `web starters` 不包含 `Validation Starter` 了 ##

详情见：[官方文档：Validation Starter no longer included in web starters][Validation Starter no longer included in web starters]  
自己添加`Validation Starter`吧

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

# 参考资料 #

[官网：Validating Form Input][Validating Form Input]  
[Hibernate Validator JSR 303 的参考实现][Hibernate Validator JSR 303]  
[Spring Framework provides support for the Java Bean Validation API.][]

[springboot使用hibernate validator校验][springboot_hibernate validator]  
[Spring Boot：Spring Validation数据校验][Spring Boot_Spring Validation]  
[springboot全局异常捕获统一处理及整合Validation][springboot_Validation]  
[Spring Boot 全局异常处理 与 Hibernate Validator校验框架整合][Spring Boot _ _ Hibernate Validator]

[Link 1]: https://juejin.cn/user/694547078710942
[validator]: https://juejin.cn/post/6844903902811275278
[Validation Starter no longer included in web starters]: https://github.com/spring-projects/spring-boot/wiki/Spring-Boot-2.3-Release-Notes#validation-starter-no-longer-included-in-web-starters
[Validating Form Input]: https://spring.io/guides/gs/validating-form-input/
[Hibernate Validator JSR 303]: https://docs.jboss.org/hibernate/validator/4.2/reference/zh-CN/html_single/#validator-gettingstarted
[Spring Framework provides support for the Java Bean Validation API.]: https://docs.spring.io/spring-framework/docs/current/spring-framework-reference/core.html#validation-beanvalidation
[springboot_hibernate validator]: https://www.cnblogs.com/mr-yang-localhost/p/7812038.html
[Spring Boot_Spring Validation]: https://blog.csdn.net/qq_40008535/article/details/94309450
[springboot_Validation]: https://blog.csdn.net/songguopeng/article/details/98961787
[Spring Boot _ _ Hibernate Validator]: https://blog.csdn.net/Anenan/article/details/84313934