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尝试运行简单的密码查询时遇到一个奇怪的异常。首先我将介绍我的代码，然后我将展示导致异常的原因。所以我有以下课程：

一个表示用户配置文件的简单类：

public abstract class Profile extends AbstractEntity {

    @Indexed
    ProfileType profileType;

    @Indexed(indexType = IndexType.FULLTEXT, indexName = "name")
    String firstName;

    @Indexed(indexType = IndexType.FULLTEXT, indexName = "name")
    String lastName;

    @Indexed
    EyeColor eyeColor;

    @Indexed    
    HairColor hairColor;

    @Indexed
    Nationality nationality;

    @Indexed
    int height;

    public Profile() {
        setProfileType();
    }

    public Profile(String firstName, String lastName, Nationality nationality, EyeColor eyeColor, HairColor hairColor, int height) {
        this();
        this.setFirstName(firstName);
        this.setLastName(lastName);
        this.setNationality(nationality);
        this.setHairColor(hairColor);
        this.setEyeColor(eyeColor);
        this.setHeight(height);
    }   

    /* Getters and Setters */
}

还有一个简单的类，它继承自Profile并代表平民：

@NodeEntity
public class Civilian extends Profile {

    @GraphProperty(propertyType = Long.class)
    DateTime dateOfBirth;

    @Indexed
    boolean missing;

    @RelatedTo
    @Fetch
    Set<Casualty> casualties = new HashSet<Casualty>(); //TODO: design

    public Civilian() {
        this.profileType = ProfileType.CIVILIAN;
    }

    public Civilian(String firstName, String lastName, Nationality nationality, EyeColor eyeColor, HairColor hairColor, int height, DateTime dateOfBirth, boolean missing) {
        super(firstName, lastName, nationality, eyeColor, hairColor, height);
        this.setDateOfBirth(dateOfBirth);
        this.setMissing(missing);
    }

    /* Getters and Setters */
}

所以我为该类创建了以下存储库Civilian：

public interface CivilianRepository extends GraphRepository<Civilian> {
    @Query("start n=node(*) where n.firstName=~{0} return n")   
    Page<Civilian> findCiviliansProperties(String firstName, Pageable page);    
}

好的。所以我创建了几个Civilian节点，并用它们填充了图表。图中没有其他节点，除了Civilian节点。当我运行该findCiviliansProperties方法时，出现以下异常：

Exception in thread "main" org.springframework.dao.InvalidDataAccessResourceUsageException: Error executing statement start n=node(*) where n.firstName=~{0} return n skip 0 limit 10; nested exception is org.springframework.dao.InvalidDataAccessResourceUsageException: Error executing statement start n=node(*) where n.firstName=~{0} return n skip 0 limit 10; nested exception is org.neo4j.cypher.EntityNotFoundException: The property 'firstName' does not exist on Node[0]
    at org.springframework.data.neo4j.support.query.CypherQueryEngine.query(CypherQueryEngine.java:52)
    at org.springframework.data.neo4j.repository.query.GraphRepositoryQuery.dispatchQuery(GraphRepositoryQuery.java:98)
    at org.springframework.data.neo4j.repository.query.GraphRepositoryQuery.execute(GraphRepositoryQuery.java:81)
    at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.invoke(RepositoryFactorySupport.java:312)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)
    at org.springframework.transaction.interceptor.TransactionInterceptor$1.proceedWithInvocation(TransactionInterceptor.java:96)
    at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:260)
    at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:94)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)
    at org.springframework.dao.support.PersistenceExceptionTranslationInterceptor.invoke(PersistenceExceptionTranslationInterceptor.java:155)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)
    at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:204)
    at com.sun.proxy.$Proxy33.findCiviliansProperties(Unknown Source)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:317)
    at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:198)
    at com.sun.proxy.$Proxy36.findCiviliansProperties(Unknown Source)
    at org.technion.socialrescue.playground.Playground.main(Playground.java:38)
Caused by: org.springframework.dao.InvalidDataAccessResourceUsageException: Error executing statement start n=node(*) where n.firstName=~{0} return n skip 0 limit 10; nested exception is org.neo4j.cypher.EntityNotFoundException: The property 'firstName' does not exist on Node[0]
    at org.springframework.data.neo4j.support.query.CypherQueryEngine.parseAndExecuteQuery(CypherQueryEngine.java:63)
    at org.springframework.data.neo4j.support.query.CypherQueryEngine.query(CypherQueryEngine.java:49)
    ... 20 more
Caused by: org.neo4j.cypher.EntityNotFoundException: The property 'firstName' does not exist on Node[0]
    at org.neo4j.cypher.internal.commands.expressions.Property.apply(Property.scala:35)
    at org.neo4j.cypher.internal.commands.expressions.Property.apply(Property.scala:29)
    at org.neo4j.cypher.internal.commands.RegularExpression.isMatch(Predicate.scala:259)
    at org.neo4j.cypher.internal.pipes.FilterPipe$$anonfun$createResults$1.apply(FilterPipe.scala:29)
    at org.neo4j.cypher.internal.pipes.FilterPipe$$anonfun$createResults$1.apply(FilterPipe.scala:29)
    at scala.collection.Iterator$$anon$22.hasNext(Iterator.scala:390)
    at scala.collection.Iterator$$anon$19.hasNext(Iterator.scala:334)
    at scala.collection.Iterator$class.isEmpty(Iterator.scala:272)
    at scala.collection.Iterator$$anon$19.isEmpty(Iterator.scala:333)
    at org.neo4j.cypher.internal.pipes.SlicePipe.createResults(SlicePipe.scala:32)
    at org.neo4j.cypher.internal.pipes.ColumnFilterPipe.createResults(ColumnFilterPipe.scala:37)
    at org.neo4j.cypher.internal.executionplan.ExecutionPlanImpl$$anonfun$6.apply(ExecutionPlanImpl.scala:127)
    at org.neo4j.cypher.internal.executionplan.ExecutionPlanImpl$$anonfun$6.apply(ExecutionPlanImpl.scala:125)
    at org.neo4j.cypher.internal.executionplan.ExecutionPlanImpl.execute(ExecutionPlanImpl.scala:33)
    at org.neo4j.cypher.ExecutionEngine.execute(ExecutionEngine.scala:59)
    at org.neo4j.cypher.ExecutionEngine.execute(ExecutionEngine.scala:63)
    at org.neo4j.cypher.javacompat.ExecutionEngine.execute(ExecutionEngine.java:79)
    at org.springframework.data.neo4j.support.query.CypherQueryEngine.parseAndExecuteQuery(CypherQueryEngine.java:61)
    ... 21 more
Caused by: org.neo4j.graphdb.NotFoundException: 'firstName' property not found for NodeImpl#0.
    at org.neo4j.kernel.impl.core.Primitive.newPropertyNotFoundException(Primitive.java:184)
    at org.neo4j.kernel.impl.core.Primitive.getProperty(Primitive.java:179)
    at org.neo4j.kernel.impl.core.NodeImpl.getProperty(NodeImpl.java:52)
    at org.neo4j.kernel.impl.core.NodeProxy.getProperty(NodeProxy.java:155)
    at org.neo4j.cypher.internal.commands.expressions.Property.apply(Property.scala:33)
    ... 38 more

所以关于这个例外最重要的是下面这行 - The property 'firstName' does not exist on Node[0].. 但它怎么可能呢？图中只有Civilian节点，它们都具有firstName属性。是不是 neo4j 框架在我的图中添加了一些我不知道的隐藏节点？因为当我将查询更改为：

start n=node(*) where has(n.firstName) AND n.firstName=~{0} return n

一切正常...

怎么了？

谢谢！！

4

1 回答 1

1

neo4j创建新实例时自动附带 1 个节点，即参考节点。你应该删除这个。

graphDatabaseService.getNodeById(0).delete()
于 2013-05-03T04:12:28.863 回答