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Jsr303 and common validator implementations

2022-06-30 17:01:00 【Ibrahimo】

《 Happy people java-validator》 Learning notes

Preface

Traditional parameter verification

Suppose there is a login scenario , The login parameters are LoginForm:

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

The verification logic used is as follows ：

 public void login(LoginForm form){
    
    if(form == null){
    
         throw new RuntimeException("login Login parameters are null");
     }

     if(form.getUsername() == null  || form.getUsername().trim().isEmpty()){
    
         throw new RuntimeException("login Log in as username Non conformity ");
     }

     if(form.getPassword() == null  || form.getPassword().trim().isEmpty()){
    
         throw new RuntimeException("login Log in as password Non conformity ");
     }

     //todo business....
 }

JSR303 standard

What is? Java EE standard

java EE standard Only API, It didn't come true . Concrete implementation , By each manufacturer . for example ：

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

java se The standard that comes with it

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These are not the only , The above is javaee Some common specifications .
For some things that are not above , You need to manually introduce api rely on .

java ee Who made the specification

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

Java Community Process

from javax To jakarta

oracle Acquisition sun after ,oralce Begin to practice java Business authorization . Forced to java Pressure from the open source community ,oracle take javax standard Donated to eclipse.
But it's not allowed to use javax.*, That's why we have the present jakarta.
So there will be ：jakarta.sq.....l

Don't Follow apache.jakarta Confuse STH with STH else .

JSR303 The implementation of the - Hibernate

maven rely on 

<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 It already contains ：validation-api <dependency> <groupId>javax.validation</groupId> <artifactId>validation-api</artifactId> <version>2.0.1.Final</version> </dependency> -->

    <!--  Equivalent to jakarta.validation-api <dependency> <groupId>jakarta.validation</groupId> <artifactId>jakarta.validation-api</artifactId> <version>2.0.1</version> </dependency> -->
   <!--  For parsing message Medium el expression  -->
    <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 {
    
    	// involves SPI
        validator = Validation.buildDefaultValidatorFactory().getValidator();
    }

    public static void valid(UserInfo userInfo){
    
        // If the verification object userInfo  Not through , Then there is a verification failure message 
        Set<ConstraintViolation<UserInfo>> set =   validator.validate(userInfo);
        set.stream().forEach(cv -> {
    
            System.out.println(" attribute :"+cv.getPropertyPath()+", Property value :"+cv.getInvalidValue()+", Verification failed , Trigger rule ："+cv.getMessage());
        });
    }
}

Validator Initialization flow

Validation.buildDefaultValidatorFactory().getValidator(); The logic can be split into the following two steps ：

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

SPI
ValidationProvider(SPI) -> hibernate.jar/META-INF/services/javax.validation.spi.ValidationProvider
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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 );
	}
	
	// return ValidatorFactoryImpl
	@Override
	public ValidatorFactory buildValidatorFactory(ConfigurationState configurationState) {
    
		return new ValidatorFactoryImpl( configurationState );
	}
}

The final acquisition of ValidatorFactory: org.hibernate.validator.internal.engine.ValidatorFactoryImpl

obtain Validator

Final Validator type ： 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);
    }

Execution results
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Common constraints constraints

javax.validation.constraints

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org.hibernate.validator.constraints

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Constraints and Validator Binding relationship of —ConstraintHelper

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

		//......
	}
}

Group check

For example, above UserInfo,

  • id: stay When added Don't check , stay When editing check id
  • Other attributes , When adding or editing All check

Define groups -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 = " Age is less than {value}, A minor ",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 ->
             " attribute :" + cv.getPropertyPath() + ", Property value :" + cv.getInvalidValue() + ", Verification failed , Trigger rule ：" + cv.getMessage()
        ).collect(Collectors.toList());

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

Cascade check

UserInfo in grade Grade information , Grade information has its own verification rules .

@Data
public class UserInfo {
    
   // A little ...
    @javax.validation.Valid // Cascade check 
    private Grade grade;
}
@Data
public class Grade {
    
    @NotEmpty
    private String gradeNo;

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

In execution validator.validate(userInfo), If you need to open cascading annotation , You need to use @javax.validation.Valid annotation .

Custom check

Define validation rules constraints

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

Definition 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 check

In the previous article validator, All non-compliance verification information will be collected , To return to .
How to set up , A non-compliance message was found , Return immediately .

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

Not javabean check

UserInfoService

public class UserInfoService {
    
    public String getByName(@NotNull  String name) throws NoSuchMethodException {
    
        //  check ...
        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 ->
             " attribute :" + cv.getPropertyPath() + ", Property value :" + cv.getInvalidValue() + ", Verification failed , Trigger rule ：" + cv.getMessage()
        ).collect(Collectors.toList());

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

Springboot check

Springboot Environment building

maven rely on 
  <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 The main class 

@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 " Verification failed ";
        }
        return " Add success ";
    }
}

Springmvc check - declarative

@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()+", Values that fail to pass the verification ："+fieldError.getRejectedValue() );
            });
        }
        return " Add success ";
    }

@javax.validation.Valid Cannot specify grouping .

@org.springframework.validation.annotation.Validated - Assign groups 

 @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()+", Values that fail to pass the verification ："+fieldError.getRejectedValue() );
            });
        }
        return " Add success ";
    }

Unified exception handling

controller – nothing BindingResult Handle 

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

If the verification fails , It will throw an exception directly .

@ExceptionHandler

At every controller Add @ExceptionHandler Method of annotation , To deal with the controller Exception information for .

  @ExceptionHandler(BindException.class)
   public String handlerEx(BindException e){
    
       List<FieldError> fieldErrors = e.getFieldErrors();
       StringBuilder sb = new StringBuilder();
       fieldErrors.forEach(fe ->
               sb.append(" attribute :").append(fe.getField()).append(" Verification failed , reason :").append(fe.getDefaultMessage()).append(";")
       );

       return sb.toString();
   }

Global exception handling -ControllerAdvice

See ：SpringMVC- characteristic annotation - @ControllerAdvice part .

Valid and Validate difference

  1. Validate Support grouping
  2. Validate Support automatic verification on method parameters .
	@GetMapping("/getByName")
 	 // Add... To a method or class  @Validated :@Null Fang Youxian 
    public String getByName(@NotNull String name){
    
        return "name:" + name;
    }

At this time @Null Verification does not work , It needs to be Method or class To add @Validate annotation .
When you add this annotation to a class , If the verification fails , Throw out ConstraintViolationException abnormal .


   @ExceptionHandler(ConstraintViolationException.class)
   public String handlerEx2(ConstraintViolationException e){
    
       Set<ConstraintViolation<?>> constraintViolations = e.getConstraintViolations();
       StringBuilder sb = new StringBuilder();
      //TODO ....
       return sb.toString();
   }
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版权声明
本文为[Ibrahimo]所创，转载请带上原文链接，感谢
https://yzsam.com/2022/181/202206301522185442.html

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