java.lang.ClassNotFoundException: javax.validation.Validation

Question

import java.util.ArrayList;
import java.util.List;
import java.util.Set;
import javax.validation.ConstraintViolation;
import javax.validation.Valid;
import javax.validation.Validation;
import javax.validation.Validator;
import javax.validation.ValidatorFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.HttpStatus;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.server.ResponseStatusException;
import lombok.extern.slf4j.Slf4j;
import com.example.demo.entity.Country;
import com.example.demo.repository.CountryRepository;

@Slf4j
@RestController
@RequestMapping("/countries")
public class CountryController {
    @Autowired
    private Country country;
    
    @PostMapping
    public Country addCountry(@RequestBody @Valid Country country){
        log.info("Started");
        // Create validator factory

        ValidatorFactory factory = Validation.buildDefaultValidatorFactory();
        Validator validator = factory.getValidator();
        // Validation is done against the annotations defined in country bean
        Set<ConstraintViolation<Country>> violations = validator.validate(country);
        List<String> errors = new ArrayList<String>();
        // Accumulate all errors in an ArrayList of type String
        for (ConstraintViolation<Country> violation : violations) {
            errors.add(violation.getMessage());
        }
        // Throw exception so that the user of this web service receives appropriate error message
        if (violations.size() > 0) {
            throw new ResponseStatusException(HttpStatus.BAD_REQUEST, errors.toString());
        }
        return country;
    }
        
}

每当我发送post请求时，我都会收到错误消息java.lang.ClassNotFoundException: javax.validation.Validation。我尝试在git bash -> curl -i -H 'Content-Type: application/json‘-X POST -s -d '{"code":" in "，"nae":"India"}’http://localhost:8080/countries中写下这段代码，得到错误信息

Answer 1

您必须将javax.validation应用程序接口的实现添加到项目的依赖项中。如果您使用maven构建它，则可以在pom文件的依赖项部分添加以下内容。

<dependency>
  <groupId>org.hibernate</groupId>
  <artifactId>hibernate-validator</artifactId>
  <version>6.1.2.Final</version>
</dependency>

Answer 2

此问题是由于hibernate-validator依赖项的版本不正确造成的。您需要尝试此依赖项的其他版本来解决此问题。

在pom文件中添加以下依赖项可能会解决此问题：

<dependency>
    <groupId>javax.validation</groupId>
    <artifactId>validation-api</artifactId>
    <version>1.0.0.GA</version>
</dependency>
 
<dependency>
    <groupId>org.hibernate</groupId>
    <artifactId>hibernate-validator</artifactId>
    <version>4.3.1.Final</version>
</dependency>