Java 如何手动触发spring验证？

从json请求体创建POJO时，POJO字段上的带注释的spring验证会起作用。但是，当我手动创建同一个对象（使用setter）并希望触发验证时，我不确定如何执行该操作

下面是注册类，它具有可以构建对象的生成器内部类。在构建方法中，我想触发spring验证。请滚动到底部并检查Builder.build（）和Builder.valiate（）方法以查看当前的实现。我使用javax.validation.Validator触发验证，但如果可能的话，我更喜欢利用spring验证

package com.projcore.dao;

import com.projcore.util.ToString;
import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
import org.hibernate.validator.constraints.NotEmpty;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import javax.validation.ConstraintViolation;
import javax.validation.Valid;
import javax.validation.Validation;
import javax.validation.Validator;
import javax.validation.constraints.Size;
import java.util.List;
import java.util.Set;

/**
 * The data transfer object that contains the information of a Registration
 * and validation rules for attributes.
 */
@JsonIgnoreProperties(ignoreUnknown = true)
public final class Registration {
    private static final Logger LOGGER = LoggerFactory.getLogger(Registration.class);

    private String id;

    @NotEmpty
    @Size(max = 255)
    private String messageId;

    @NotEmpty
    @Size(max = 255)
    private String version;

    @Size(max = 255)
    private String system;

    public Registration() {
    }

    private Registration(Builder builder) {
        this.id = builder.id;
        this.messageId = builder.messageId;
        this.version = builder.version;
        this.system = builder.system;
    }

    public static Builder getBuilder() {
        return new Builder();
    }

    public String getId() {
        return id;
    }

    public void setId(String id) {
        this.id = id;
    }

    public String getMessageId() {
        return messageId;
    }

    public void setMessageId(String messageId) {
        this.messageId = messageId;
    }

    public String getVersion() {
        return version;
    }

    public void setVersion(String version) {
        this.version = version;
    }

    public String getSystem() {
        return system;
    }

    public void setSystem(String system) {
        this.system = system;
    }

    @Override
    public String toString() {
        return ToString.create(this);
    }

    /**
     * Builder pattern makes the object easier to construct in one line.
     */
    public static class Builder {

        private String id;

        private String messageId;

        private String version;

        private String system;

        private Builder() {}

        public Builder id(String id) {
            this.id = id;
            return this;
        }

        public Builder messageId(String messageId) {
            this.messageId = messageId;
            return this;
        }


        public Builder version(String version) {
            this.version = version;
            return this;
        }

        public Builder system(String system) {
            this.system = system;
            return this;
        }

        public Registration build() {
            Registration entry = new Registration(this);

            // *** Would like to trigger spring validation here ***
            Set violations = validate(entry);
            if (violations.isEmpty())
                return entry;
            else
                throw new RuntimeException(violations.toString());
        }

        private Set validate(Registration entry) {
            Validator validator = Validation.buildDefaultValidatorFactory().getValidator();
            Set<ConstraintViolation<Registration>> constraintViolations = validator.validate(entry);
            return constraintViolations;
        }

    }
}

---

解决方案：

已删除registration.Builder.validate（）。已将registration.Builder.build（）更新为：

ValidationUtil.java

package projcore.util;

import com.ericsson.admcore.error.InvalidDataException;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.stereotype.Service;
import org.springframework.validation.BeanPropertyBindingResult;
import org.springframework.validation.Errors;
import org.springframework.validation.beanvalidation.SpringValidatorAdapter;

import javax.validation.Validation;
import javax.validation.Validator;
import java.util.Set;

public class ValidatorUtil {
    private static final Logger LOGGER = LoggerFactory.getLogger(ValidatorUtil.class);
    private static final Validator javaxValidator = Validation.buildDefaultValidatorFactory().getValidator();
    private static final SpringValidatorAdapter validator = new SpringValidatorAdapter(javaxValidator);

    public static Object validate(Object entry) {
        Errors errors = new BeanPropertyBindingResult(entry, entry.getClass().getName());
        validator.validate(entry, errors);
        if (errors == null || errors.getAllErrors().isEmpty())
            return entry;
        else {
            LOGGER.error(errors.toString());
            throw new InvalidDataException(errors.getAllErrors().toString(), errors);
        }
    }
}

InvalidDataException.java

package projcore.error;

import org.springframework.validation.Errors;

/**
 * This exception is thrown when the dao has invalid data.
 */
public class InvalidDataException extends RuntimeException {
    private Errors errors;

    public InvalidDataException(String msg, Errors errors) {
        super(msg);
        setErrors(errors);
    }

    public Errors getErrors() {
        return errors;
    }

    public void setErrors(Errors errors) {
        this.errors = errors;
    }
}

---

Spring提供了对JSR-303bean验证API的全面支持。这包括方便地支持将JSR-303实现引导为Springbean。这允许在应用程序中需要验证的任何地方注入javax.validation.Validator

使用LocalValidatorFactoryBean将默认JSR-303验证器配置为SpringBean：

   <bean id="validator" class="org.springframework.validation.beanvalidation.LocalValidatorFactoryBean" />

如果您的bean需要Spring验证API，则插入对

org.springframework.validation.Validator的引用：

// Spring Validator
import org.springframework.validation.Validator;

@Service
public class MyService {

    @Autowired
    private Validator validator;

}

这里有一个很好的例子

这个链接非常有用。在中包装javax.validation.Validator
org.springframework.validation.beanvalidation.SpringValidatorAdapter
帮助始终如一地处理错误。你能加上这个作为答案吗
我可以接受

及
我认为Spring Boot还为您提供了验证器bean（并不是说您自己很难做到）。这是否意味着Spring Validator只能在@Service类中用于触发验证？我已经在网上读了足够多的书，所以看到过这样的例子，但我仍然不明白如何在POJO中做到这一点，因此我提出了这个问题。我还知道如何触发自定义验证器的验证，但不知道如何触发POJO中的默认验证。如果可能的话，您可以在我所拥有的上下文中提供具体的答案。您可以将验证器注入任何Springbean。这里有一个古老的例子。如果你还有问题，请在此发表评论。此链接非常有用。在org.springframework.validation.beanvalidation.SpringValidatorAdapter中包装javax.validation.Validator有助于一致地处理错误。你能把这个添加为我可以接受的答案吗？我已经编辑了这个答案以包含链接，所以你可以接受这个答案，我很高兴我能提供帮助
   <bean id="validator" class="org.springframework.validation.beanvalidation.LocalValidatorFactoryBean" />

// JSR-303 Validator
import javax.validation.Validator;

@Service
public class MyService {

    @Autowired
    private Validator validator;

}

// Spring Validator
import org.springframework.validation.Validator;

@Service
public class MyService {

    @Autowired
    private Validator validator;

}