java - 不存在主 SDN 标签..(即以 _ 开头的标签)

Question

Spring数据neo4j版本:3.3.0.RELEASENeo4j版本:2.2.2

当我尝试查询 spring-data 存储库上公开的默认方法时，我遇到了以下异常，即

personRepository.findAll(getDefaultPageable());

public static Pageable getDefaultPageable() {
    BiFunction<Integer, Integer, Pageable> biFunction = PageRequest::new; // Method reference syntax in action
    return biFunction.apply(DEFAULT_PAGE_NUMBER, DEFAULT_PAGE_SIZE);
}

Caused by: java.lang.IllegalStateException: No primary SDN label exists .. (i.e one starting with _) at org.springframework.data.neo4j.support.typerepresentation.LabelBasedNodeTypeRepresentationStrategy.readAliasFrom(LabelBasedNodeTypeRepresentationStrategy.java:136) at org.springframework.data.neo4j.support.typerepresentation.LabelBasedNodeTypeRepresentationStrategy.readAliasFrom(LabelBasedNodeTypeRepresentationStrategy.java:40) at org.springframework.data.neo4j.support.mapping.TRSTypeAliasAccessor.readAliasFrom(TRSTypeAliasAccessor.java:36) at org.springframework.data.neo4j.support.mapping.TRSTypeAliasAccessor.readAliasFrom(TRSTypeAliasAccessor.java:26) at org.springframework.data.convert.DefaultTypeMapper.readType(DefaultTypeMapper.java:102) at org.springframework.data.convert.DefaultTypeMapper.getDefaultedTypeToBeUsed(DefaultTypeMapper.java:165) at org.springframework.data.convert.DefaultTypeMapper.readType(DefaultTypeMapper.java:142) at org.springframework.data.neo4j.support.mapping.Neo4jEntityConverterImpl.read(Neo4jEntityConverterImpl.java:77) at org.springframework.data.neo4j.support.mapping.Neo4jEntityPersister$CachedConverter.read(Neo4jEntityPersister.java:170) at org.springframework.data.neo4j.support.mapping.Neo4jEntityPersister.createEntityFromState(Neo4jEntityPersister.java:189) at org.springframework.data.neo4j.support.mapping.Neo4jEntityPersister.projectTo(Neo4jEntityPersister.java:216) at org.springframework.data.neo4j.support.Neo4jTemplate.projectTo(Neo4jTemplate.java:241) at org.springframework.data.neo4j.support.conversion.EntityResultConverter.doConvert(EntityResultConverter.java:73) at org.springframework.data.neo4j.conversion.DefaultConverter.convert(DefaultConverter.java:44) at org.springframework.data.neo4j.support.conversion.EntityResultConverter.convert(EntityResultConverter.java:165) at org.springframework.data.neo4j.conversion.QueryResultBuilder$1.underlyingObjectToObject(QueryResultBuilder.java:86) at org.neo4j.helpers.collection.IterableWrapper$MyIteratorWrapper.underlyingObjectToObject(IterableWrapper.java:57) at org.neo4j.helpers.collection.IteratorWrapper.next(IteratorWrapper.java:47) at org.springframework.data.neo4j.repository.AbstractGraphRepository.subList(AbstractGraphRepository.java:371) at org.springframework.data.neo4j.repository.AbstractGraphRepository.extractPage(AbstractGraphRepository.java:355) at org.springframework.data.neo4j.repository.AbstractGraphRepository.findAll(AbstractGraphRepository.java:321) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:497) at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.executeMethodOn(RepositoryFactorySupport.java:414) at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.doInvoke(RepositoryFactorySupport.java:399) at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.invoke(RepositoryFactorySupport.java:371) at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) at org.springframework.data.projection.DefaultMethodInvokingMethodInterceptor.invoke(DefaultMethodInvokingMethodInterceptor.java:61) at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) at org.springframework.transaction.interceptor.TransactionInterceptor$1.proceedWithInvocation(TransactionInterceptor.java:99) at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:281) at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:96) at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) at org.springframework.dao.support.PersistenceExceptionTranslationInterceptor.invoke(PersistenceExceptionTranslationInterceptor.java:136) at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:207) at com.sun.proxy.$Proxy60.findAll(Unknown Source) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:497) at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:317) at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:201) at com.sun.proxy.$Proxy61.findAll(Unknown Source)

我真的不想在这里做任何复杂的事情，所以我很难理解我是否真的应该引入带有下划线前缀标签的自定义查询并使用注释@Query？ Spring 数据中的默认方法不是只适用于 SDN 吗？

<小时/>

## 更新 ##

我调整了密码查询，但仍然出现相同的错误。

used by: java.lang.IllegalStateException: No primary SDN label exists .. (i.e one starting with _) at org.springframework.data.neo4j.support.typerepresentation.LabelBasedNodeTypeRepresentationStrategy.readAliasFrom(LabelBasedNodeTypeRepresentationStrategy.java:136) at org.springframework.data.neo4j.support.typerepresentation.LabelBasedNodeTypeRepresentationStrategy.readAliasFrom(LabelBasedNodeTypeRepresentationStrategy.java:40) at org.springframework.data.neo4j.support.mapping.TRSTypeAliasAccessor.readAliasFrom(TRSTypeAliasAccessor.java:36) at org.springframework.data.neo4j.support.mapping.TRSTypeAliasAccessor.readAliasFrom(TRSTypeAliasAccessor.java:26) at org.springframework.data.convert.DefaultTypeMapper.readType(DefaultTypeMapper.java:102) at org.springframework.data.convert.DefaultTypeMapper.getDefaultedTypeToBeUsed(DefaultTypeMapper.java:165) at org.springframework.data.convert.DefaultTypeMapper.readType(DefaultTypeMapper.java:142) at org.springframework.data.neo4j.support.mapping.Neo4jEntityConverterImpl.read(Neo4jEntityConverterImpl.java:77) at org.springframework.data.neo4j.support.mapping.Neo4jEntityPersister$CachedConverter.read(Neo4jEntityPersister.java:170) at org.springframework.data.neo4j.support.mapping.Neo4jEntityPersister.createEntityFromState(Neo4jEntityPersister.java:189) at org.springframework.data.neo4j.support.Neo4jTemplate.createEntityFromState(Neo4jTemplate.java:224)

你能看一下这些类(class)，让我知道我哪里做错了，哪里做错了吗？

这是存储库类

public interface PersonRepository extends GraphRepository<Person>, CypherDslRepository<Person> {
String PERSONS_WITH_SEVERAL_ACME_IDENTITY = "MATCH (p:Person)-[r:HAS_LOGIN]->(a:AcmeIdp) " +
        "SET p:_Person, a:_AcmeIdp "+
        "WITH p, count(p) AS numoutgoing " +
        "WHERE numoutgoing > 1 " +
        "MATCH (p:Person)-[r:HAS_LOGIN]->(a:AcmeIdp) " +
        "SET p:_Person, a:_AcmeIdp "+
        "RETURN p";

Iterable<Person> findByFirstNameAndLastName(@NonNull final String firstName,@NonNull final String lastName);

Page<Person> findByFirstNameLike(@NonNull final String firstName,@NonNull final Pageable pageable);

@Query(PERSONS_WITH_SEVERAL_ACME_IDENTITY)
Page<Person> findOnesWithSeveralAcmeIdentities(@NonNull final Pageable pageable); }

人员实体类

import com.example.analytics.model.AbstractEntity;
import com.example.analytics.model.relationship.Login;
import org.checkerframework.checker.nullness.qual.NonNull;
import org.neo4j.graphdb.Direction;
import org.springframework.data.neo4j.annotation.*;

import java.time.LocalDateTime;
import java.util.Set;

@NodeEntity(useShortNames = true)
public class Person extends AbstractEntity {

    @GraphProperty(propertyName = "title", defaultValue = "")
    private String title;

    @GraphProperty(propertyName = "firstName", defaultValue = "")
    private String firstName;

    @GraphProperty(propertyName = "lastName", defaultValue = "")
    private String lastName;

    @GraphProperty(propertyName = "dateOfBirth", propertyType = String.class)
    private LocalDateTime dateOfBirth;

    @RelatedTo(type = "HAS_LOGIN", direction = Direction.OUTGOING, elementClass = AcmeIdentity.class)
    private Set<Login> logins;

    public String getTitle() {
        return title;
    }

    public void setTitle(final String title) {
        this.title = title;
    }

    public String getFirstName() {
        return firstName;
    }

    public void setFirstName(final String firstName) {
        this.firstName = firstName;
    }

    public String getLastName() {
        return lastName;
    }

    public void setLastName(final String lastName) {
        this.lastName = lastName;
    }

    public LocalDateTime getDateOfBirth() {
        return dateOfBirth;
    }

    public void setDateOfBirth(final LocalDateTime dateOfBirth) {
        this.dateOfBirth = dateOfBirth;
    }

    public Set<Login> getLogins() {
        return logins;
    }

    public void setLogins(@NonNull final Set<Login> logins) {
        this.logins = logins;
    }
}

转换器

import org.checkerframework.checker.nullness.qual.NonNull;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.core.convert.converter.Converter;
import org.springframework.stereotype.Component;

import java.time.LocalDateTime;
import java.time.format.DateTimeFormatter;

@Component
public class LocalDateTimeToStringConverter implements Converter<LocalDateTime, String> {

    private static final Logger LOG = LoggerFactory.getLogger(LocalDateTimeToStringConverter.class);

    @Value("${neo4j.dateTime.format:yyyy-MM-dd HH:mm:ss}")
    private String dateTimeFormat;

    @Override
    public String convert(@NonNull final LocalDateTime source) {
        LOG.debug("Converting LocalDateTime into String using the format: {}", dateTimeFormat);
        return String.valueOf(source.format(DateTimeFormatter.ofPattern(dateTimeFormat)));
    }

}

反向转换器

import org.checkerframework.checker.nullness.qual.NonNull;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.core.convert.converter.Converter;
import org.springframework.stereotype.Component;

import javax.annotation.PostConstruct;
import java.time.LocalDateTime;
import java.time.format.DateTimeFormatter;

@Component
public class StringToLocalDateTimeConverter implements Converter<String, LocalDateTime> {

    private static final Logger LOG = LoggerFactory.getLogger(StringToLocalDateTimeConverter.class);

    @Value("${neo4j.dateTime.format:yyyy-MM-dd HH:mm:ss}")
    private String dateTimeFormat;

    /**
     * Convert the source of type S to target type T.
     *
     * @param source the source object to convert, which must be an instance of S (never {@code null})
     * @return the converted object, which must be an instance of T (potentially {@code null})
     * @throws IllegalArgumentException if the source could not be converted to the desired target type
     */
    @Override
    public LocalDateTime convert(@NonNull final String source) {
        LOG.debug("Converting String {} into LocalDateTime using the format: {}",source, dateTimeFormat);
        return LocalDateTime.parse(source, DateTimeFormatter.ofPattern(dateTimeFormat));
    }

}

主要配置类

import com.example.analytics.converter.LocalDateTimeToStringConverter;
import com.example.analytics.converter.StringToLocalDateTimeConverter;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
import org.springframework.context.annotation.*;
import org.springframework.context.support.PropertySourcesPlaceholderConfigurer;
import org.springframework.core.convert.ConversionService;
import org.springframework.core.convert.converter.ConverterRegistry;
import org.springframework.data.neo4j.config.Neo4jConfiguration;
import org.springframework.transaction.annotation.EnableTransactionManagement;

@Configuration
@EnableAutoConfiguration
@EnableTransactionManagement(mode = AdviceMode.PROXY)
@ComponentScan(basePackages = {"com.example.analytics"})
@PropertySource(value = "classpath:application.yml", ignoreResourceNotFound = false)
@Import({DatabaseConnectionConfiguration.class})
public class MainConfiguration extends Neo4jConfiguration {

    @Autowired
    private StringToLocalDateTimeConverter stringToLocalDateTimeConverter;

    @Autowired
    private LocalDateTimeToStringConverter localDateTimeToStringConverter;

    private static final Logger LOG = LoggerFactory.getLogger(MainConfiguration.class);

    public MainConfiguration() {
        setBasePackage("com.example.analytics.model");
    }

    @Bean
    public static PropertySourcesPlaceholderConfigurer propertyConfigIn() {
        return new PropertySourcesPlaceholderConfigurer();
    }

    @Bean
    @DependsOn({ "stringToLocalDateTimeConverter", "localDateTimeToStringConverter" })
    protected ConversionService neo4jConversionService() throws Exception {
        LOG.debug("Adding custom converters to conversion service ...");
        ConversionService conversionService = super.neo4jConversionService();
        ConverterRegistry registry = (ConverterRegistry) conversionService;
        registry.addConverter(stringToLocalDateTimeConverter);
        registry.addConverter(localDateTimeToStringConverter);
        LOG.debug("Addition of Converter from LocalDateTime to String and vice-versa has been completed!");
        return conversionService;
    }
}

使用存储库的服务片段

public Page<Person> findPersonsWithSeveralAcmeIdentitites(final Pageable pageable) {
    LOG.debug("Fetching persons with several ACME identities");

    if(pageable != null)
        return personRepository.findOnesWithSeveralAcmeIdentities(pageable);
   else 
        return personRepository.findOnesWithSeveralAcmeIdentities(getDefaultPageable());

}

Answer 1

然后，您必须检查节点并在每个节点上调用:

neo4jTemplate.postEntityCreation(node, MyEntity.class);

或者这也应该有效:

MATCH (n:User) set n:_User;

等等

我认为你对 Java8 方法引用过度了!!!只需使用普通的旧new即可。否则你的代码将来将无法维护。

public static Pageable getDefaultPageable() {
    return new PageRequest(DEFAULT_PAGE_NUMBER, DEFAULT_PAGE_SIZE);
}