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JSR303以及常见Validator实现

2022-06-30 15:48:00 【伊布拉西莫】

《乐之者java-validator》学习笔记

前言

传统参数校验

假设有登录场景，登录参数为LoginForm:

@Data
public class LoginForm {
    
    private String username;
    private String password;
}

使用校验逻辑如下：

 public void login(LoginForm form){
    
    if(form == null){
    
         throw new RuntimeException("login登录时参数为null");
     }

     if(form.getUsername() == null  || form.getUsername().trim().isEmpty()){
    
         throw new RuntimeException("login登录时为username不合规");
     }

     if(form.getPassword() == null  || form.getPassword().trim().isEmpty()){
    
         throw new RuntimeException("login登录时为password不合规");
     }

     //todo business....
 }

JSR303 规范

什么是Java EE 规范

java EE 规范只有API，没有实现。 具体的实现，由各厂商实现。例如：

  • javax.sql.*
  • javax.servlet
  • javax.jmx
  • …

java se自带的规范

在这里插入图片描述
并不是仅有这些，上述为javaee常见的一些规范。
对于一些上面没有的，则需要手动引入api依赖。

java ee规范由谁制定

https://jcp.org/en/home/index

Java Community Process

从javax 到 jakarta

oracle收购sun之后,oralce开始实行java商业授权。迫于java开源社区的压力，oracle将javax规范捐献给了eclipse.
但是不允许使用javax.*，所以才有了现在的jakarta。
所以以后会出现：jakarta.sq.....l

不要跟apache.jakarta混为一谈。

JSR303的实现 - Hibernate

maven依赖

<dependency>
      <groupId>org.hibernate.validator</groupId>
      <artifactId>hibernate-validator</artifactId>
      <version>6.0.18.Final</version>
      <exclusions>
        <exclusion>
          <groupId>jakarta.validation</groupId>
          <artifactId>jakarta.validation-api</artifactId>
        </exclusion>
      </exclusions>
    </dependency>

    <!-- hibernate-validator中已经包含了：validation-api <dependency> <groupId>javax.validation</groupId> <artifactId>validation-api</artifactId> <version>2.0.1.Final</version> </dependency> -->

    <!-- 等价于jakarta.validation-api <dependency> <groupId>jakarta.validation</groupId> <artifactId>jakarta.validation-api</artifactId> <version>2.0.1</version> </dependency> -->
   <!-- 用于解析message中的el表达式 -->
    <dependency>
      <groupId>org.apache.tomcat.embed</groupId>
      <artifactId>tomcat-embed-el</artifactId>
      <version>9.0.29</version>
    </dependency>

UserInfo

@Data
public class UserInfo {
    
    private Long id;
    private String name;
    private Integer age;
    private String email;
    private LocalDate birthdate;
}

ValidatorUtil

public class ValidatorUtil {
    
    private static Validator validator;
    static {
    
    	//涉及到SPI
        validator = Validation.buildDefaultValidatorFactory().getValidator();
    }

    public static void valid(UserInfo userInfo){
    
        //如果校验对象userInfo 不通过，则存在校验不通过信息
        Set<ConstraintViolation<UserInfo>> set =   validator.validate(userInfo);
        set.stream().forEach(cv -> {
    
            System.out.println("属性:"+cv.getPropertyPath()+",属性值:"+cv.getInvalidValue()+",校验不通过,触发规则："+cv.getMessage());
        });
    }
}

Validator初始化流程

Validation.buildDefaultValidatorFactory().getValidator();逻辑可以拆分为如下两步：

  1. Validation.buildDefaultValidatorFactory() : 获取 ValidatorFactory
  2. $1.getValidator(); : 获取Validator
获取 ValidatorFactory
	public static ValidatorFactory buildDefaultValidatorFactory() {
    
		 //1.1 byDefaultProvider() -- 返回 GenericBootstrapImpl();
         //1.2 GenericBootstrapImpl.configure() --根据SPI 加载 javax.validation.spi.ValidationProvider
         //1.3 ValidationProvider.buildValidatorFactory();
		return byDefaultProvider().configure().buildValidatorFactory();
	}

SPI
ValidationProvider(SPI) -> hibernate.jar/META-INF/services/javax.validation.spi.ValidationProvider
在这里插入图片描述

HibernateValidator

public class HibernateValidator implements ValidationProvider<HibernateValidatorConfiguration> {
    

	@Override
	public HibernateValidatorConfiguration createSpecializedConfiguration(BootstrapState state) {
    
		return HibernateValidatorConfiguration.class.cast( new ConfigurationImpl( this ) );
	}

	@Override
	public Configuration<?> createGenericConfiguration(BootstrapState state) {
    
		return new ConfigurationImpl( state );
	}
	
	//返回ValidatorFactoryImpl
	@Override
	public ValidatorFactory buildValidatorFactory(ConfigurationState configurationState) {
    
		return new ValidatorFactoryImpl( configurationState );
	}
}

最终获取的ValidatorFactory: org.hibernate.validator.internal.engine.ValidatorFactoryImpl

获取Validator

最终Validator类型： org.hibernate.validator.internal.engine.ValidatorFactoryImpl

demo1

constraints

@Data
public class UserInfo {
    
    @javax.validation.constraints.NotNull
    private Long id;

    @javax.validation.constraints.NotEmpty
    private String name;

    @org.hibernate.validator.constraints.Range
    private Integer age;

    @javax.validation.constraints.Email
    private String email;

    private LocalDate birthdate;
}

test-case

 public void test01(){
    
        UserInfo userInfo = new UserInfo();
        userInfo.setName("");
        userInfo.setAge(120);
        userInfo.setEmail("www.baidu.com");
        ValidatorUtil.valid(userInfo);
    }

执行结果
在这里插入图片描述

常见约束constraints

javax.validation.constraints

在这里插入图片描述

org.hibernate.validator.constraints

在这里插入图片描述

约束与Validator的绑定关系—ConstraintHelper

package org.hibernate.validator.internal.metadata.core;
public class ConstraintHelper {
    
	public ConstraintHelper() {
    
		Map<Class<? extends Annotation>, List<ConstraintValidatorDescriptor<?>>> tmpConstraints = new HashMap<>();
		//为NotNull.class 绑定 NotNullValidator.class
		putConstraint( tmpConstraints, NotNull.class, NotNullValidator.class );
		putConstraint( tmpConstraints, Null.class, NullValidator.class );
		putConstraint( tmpConstraints, Email.class, EmailValidator.class );

		//......
	}
}

分组校验

例如上面的UserInfo,

  • id: 在新增时不校验,在编辑时校验id
  • 其他属性，在新增或编辑时都校验

定义分组-class

public class ValidGroups {
    
    public interface  Add{
    }
    public interface  Edit{
    }
}

UserInfo

@Data
public class UserInfo {
    
    @javax.validation.constraints.NotNull(groups = {
    ValidGroups.Edit.class})
    private Long id;

    @javax.validation.constraints.NotEmpty(groups = {
    ValidGroups.Add.class,ValidGroups.Edit.class})
    private String name;

    @org.hibernate.validator.constraints.Range(min = 18,message = "年龄小于{value},未成年",groups = {
    ValidGroups.Add.class,ValidGroups.Edit.class})
    private Integer age;

    @javax.validation.constraints.Email(groups = {
    ValidGroups.Add.class,ValidGroups.Edit.class})
    private String email;

    private LocalDate birthdate;
}

javax.validation.Validator

public interface Validator {
    
	<T> Set<ConstraintViolation<T>> validate(T object, Class<?>... groups);
}

ValidatorUtil

  public  static List<String>  valid(UserInfo userInfo,Class validGroup){
    
        Set<ConstraintViolation<UserInfo>> set =   validator.validate(userInfo,validGroup);
         List<String> list = set.stream().map(cv ->
             "属性:" + cv.getPropertyPath() + ",属性值:" + cv.getInvalidValue() + ",校验不通过,触发规则：" + cv.getMessage()
        ).collect(Collectors.toList());

        list.forEach(System.out::println);
        return list;
    }

级联校验

UserInfo中存在grade年级信息,年级信息有自己的校验规则。

@Data
public class UserInfo {
    
   //略...
    @javax.validation.Valid //级联校验
    private Grade grade;
}
@Data
public class Grade {
    
    @NotEmpty
    private String gradeNo;

    @Range(min = 5,max = 40)
    private int classNum;
}

在执行validator.validate(userInfo),若需要开启级联注解，则需要使用 @javax.validation.Valid注解。

自定义校验

定义校验规则constraints

@Target({
     FIELD })
@Retention(RUNTIME)
@Documented
@Constraint(validatedBy = {
    UserStatusValidator.class }) //指定validator
public @interface UserStatus {
    
    String message() default "{user_status 必须为100/101/1002}";
    Class<?>[] groups() default {
     };
    Class<? extends Payload>[] payload() default {
     };
}

定义Validator

public class UserStatusValidator implements javax.validation.ConstraintValidator<UserStatus, Integer> {
    
    @Override
    public boolean isValid(Integer value, ConstraintValidatorContext context) {
    
        return value == 100 || value == 101 || value == 102;
    }
}

failfast 校验

前文中的validator，会将所有的不合规校验信息全部收集完成之后，才返回。
如何设置，发现一个不合规信息，立即返回。

    Validator failfastValidator = Validation.byProvider(HibernateValidator.class)
                .configure().failFast(true).buildValidatorFactory().getValidator();

非javabean校验

UserInfoService

public class UserInfoService {
    
    public String getByName(@NotNull  String name) throws NoSuchMethodException {
    
        // 校验...
        Method method = this.getClass().getDeclaredMethod("getByName", String.class);
        ValidatorUtil.validNotBean(this,method,new Object[]{
    name});
        return "name:" + name;
    }
}

ExecutableValidator

public class ValidatorUtil {
    
    private static Validator validator;
    private static ExecutableValidator executableValidator;
    static {
    
  
        validator = Validation.buildDefaultValidatorFactory().getValidator();
        executableValidator = validator.forExecutables();
    }

    public static <T> List<String>  validNotBean(T object , Method method, Object[] params , Class<?> ... groups){
    
        Set<ConstraintViolation<T>> set =  executableValidator.validateParameters(object, method, params, groups);
         List<String> list = set.stream().map(cv ->
             "属性:" + cv.getPropertyPath() + ",属性值:" + cv.getInvalidValue() + ",校验不通过,触发规则：" + cv.getMessage()
        ).collect(Collectors.toList());

        list.forEach(System.out::println);
        return list;
    }
}

Springboot 校验

Springboot环境搭建

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

  <dependencyManagement>
    <dependencies>
      <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-dependencies</artifactId>
        <version>2.6.7</version>
        <scope>import</scope>
        <type>pom</type>
      </dependency>
    </dependencies>
  </dependencyManagement>

App主类

@SpringBootApplication
public class App {
    

    public static void main( String[] args )
    {
    
        SpringApplication.run(App.class);
    }
}

Controller

@RestController
public class UserInfoController {
    

    @GetMapping("/getByName")
    public String getByName(String name){
    
        return "name:" + name;
    }

    @GetMapping("/addUser")
    public String addUser(UserInfo userInfo){
    
        List<String> list = ValidatorUtil.valid(userInfo);
        if(list.size() > 0){
    
            return "校验不成功";
        }
        return "添加成功";
    }
}

Springmvc校验 - 声明式

@javax.validation.Valid

@GetMapping("/addUser2")
    public String addUser2(@javax.validation.Valid UserInfo userInfo, BindingResult bindingResult){
    
        if(bindingResult.hasErrors()){
    
            bindingResult.getAllErrors().forEach(error ->{
    
                System.out.println(error.getObjectName()+"::"+error.getDefaultMessage());
            });

            bindingResult.getFieldErrors().forEach(fieldError -> {
    
                System.out.println(fieldError.getField()+":"+fieldError.getDefaultMessage()+",没有通过校验的值："+fieldError.getRejectedValue() );
            });
        }
        return "添加成功";
    }

@javax.validation.Valid 无法指定分组。

@org.springframework.validation.annotation.Validated - 指定分组

 @GetMapping("/addUser3")
    public String addUser3(@org.springframework.validation.annotation.Validated(ValidGroups.Add.class) UserInfo userInfo, BindingResult bindingResult){
    
        if(bindingResult.hasErrors()){
    
            bindingResult.getAllErrors().forEach(error ->{
    
                System.out.println(error.getObjectName()+"::"+error.getDefaultMessage());
            });
            bindingResult.getFieldErrors().forEach(fieldError -> {
    
                System.out.println(fieldError.getField()+":"+fieldError.getDefaultMessage()+",没有通过校验的值："+fieldError.getRejectedValue() );
            });
        }
        return "添加成功";
    }

统一异常处理

controller – 无BindingResult处理

 @GetMapping("/addUser4")
    public String addUser4(@org.springframework.validation.annotation.Validated(ValidGroups.Add.class) UserInfo userInfo){
    
        return "添加成功";
    }

若校验不通过，则会直接抛出异常。

@ExceptionHandler

在每个controller中添加@ExceptionHandler注解的方法，来处理该controller的异常信息。

  @ExceptionHandler(BindException.class)
   public String handlerEx(BindException e){
    
       List<FieldError> fieldErrors = e.getFieldErrors();
       StringBuilder sb = new StringBuilder();
       fieldErrors.forEach(fe ->
               sb.append("属性:").append(fe.getField()).append("验证不通过，原因:").append(fe.getDefaultMessage()).append(";")
       );

       return sb.toString();
   }

全局异常处理-ControllerAdvice

参见：SpringMVC-特性annotation - @ControllerAdvice部分。

Valid 和 Validate 区别

  1. Validate 支持分组
  2. Validate支持方法参数上的自动校验。
	@GetMapping("/getByName")
 	 //在方法上或者类上增加 @Validated :@Null方有效果
    public String getByName(@NotNull String name){
    
        return "name:" + name;
    }

此时的@Null校验是不起作用的，需要在该方法或者类上增加@Validate注解。
当在类上增加此注解时，若校验不通过，抛出ConstraintViolationException异常.


   @ExceptionHandler(ConstraintViolationException.class)
   public String handlerEx2(ConstraintViolationException e){
    
       Set<ConstraintViolation<?>> constraintViolations = e.getConstraintViolations();
       StringBuilder sb = new StringBuilder();
      //TODO ....
       return sb.toString();
   }
原网站

版权声明
本文为[伊布拉西莫]所创，转载请带上原文链接，感谢
https://blog.csdn.net/it_freshman/article/details/125491461

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