正確使用RelationshipEntity

我想在Neo4j中創建一個USER - > ROLE關係。我試圖利用RelationshipEntity標籤來允許人們將關係信息添加到關係中。任何人都可以幫助我，或者指點我一個關於如何創建這種關係的好資源？正確使用RelationshipEntity

下面的代碼：

用戶

@NodeEntity 
public class Person { 

    @GraphId Long id; 
    public String name; 

    @RelatedToVia(type="HAS_ROLE", direction=Direction.BOTH) 
    public @Fetch Set<Role> roles; 


    public Person() {} 
    public Person(String name) { this.name = name; } 

    // Mutators below 
}

作用

public class Role { 

    @GraphId Long id; 
    private RoleType roleType; 

    private List<Person> users; 

    private List<PrivilegeType> defaultPrivileges; 


    public Role(){} 

    public Role(RoleType roleType){ 
     this.roleType=roleType; 
     this.defaultPrivileges=roleType.getDefaultPrivileges(); 
    } 
    // Mutators below  
}

USER_ROLE_RELATIONSHIP

@RelationshipEntity(type="HAS_ROLE") 
public class UserRoleRelationship { 
    @GraphId Long id; 

    @StartNode private Person person; 

    @EndNode private Role role; 

    private List<PrivilegeType> customizedPrivileges = new ArrayList<PrivilegeType>(); 

    // Mutators below 
}

應用

@Configuration 
@EnableNeo4jRepositories(basePackages = "neo4j.bakeoff.repo") 
public class CopyOfApplication extends Neo4jConfiguration implements CommandLineRunner { 

    public CopyOfApplication() { 
     setBasePackage("neo4j.bakeoff"); 
    } 

    @Bean 
    GraphDatabaseService graphDatabaseService() { 
     return new GraphDatabaseFactory().newEmbeddedDatabase("test.db"); 
    } 

    @Autowired 
    PersonRepository personRepository; 

    @Autowired 
    RoleRepository roleRepository; 

    @Autowired 
    UserRoleRepository userRoleRepository; 

    @Autowired 
    GraphDatabase graphDatabase; 

    public void run(String... args) throws Exception { 
      // Setting up 
      Person p1 = new Person("person1"); 
      Person p2 = new Person("person1"); 

      Role admin = new Role(RoleType.ADMIN); 
      Role user = new Role(RoleType.USER); 



      System.out.println("Before linking up with Neo4j..."); 
      for (Person person : new Person[]{p1, p2}) { 
       System.out.println(person); 
      } 

      Transaction tx = graphDatabase.beginTx(); 
      try { 
       p1 = personRepository.save(p1); 
       p2 = personRepository.save(p2); 

       admin= roleRepository.save(admin); 
       user = roleRepository.save(user); 

       UserRoleRelationship rel = new UserRoleRelationship(); 
       rel.setPerson(p1); 
       rel.setRole(admin); 
       userRoleRepository.save(rel); 

       UserRoleRelationship rel2 = new UserRoleRelationship(); 
       rel.setPerson(p2); 
       rel.setRole(user); 
       userRoleRepository.save(rel2);    

       System.out.println("Lookup each person by name..."); 
       for (String name: new String[]{p1.name, p2.name}) { 
        System.out.println(personRepository.findByName(name)); 
       } 

       tx.success(); 
      } finally { 
       tx.close(); 
      } 


    } 

    public static void main(String[] args) throws Exception { 
     FileUtils.deleteRecursively(new File("test.db")); 

     SpringApplication.run(CopyOfApplication.class, args); 
    } 

}

這裏是我得到

java.lang.IllegalStateException: Failed to execute CommandLineRunner 
    at org.springframework.boot.SpringApplication.runCommandLineRunners(SpringApplication.java:680) 
    at org.springframework.boot.SpringApplication.afterRefresh(SpringApplication.java:695) 
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:321) 
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:952) 
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:941) 
    at neo4j.bakeoff.config.Application.main(Application.java:109) 
Caused by: java.lang.NullPointerException: null 
    at org.springframework.data.neo4j.support.mapping.EntityStateHandler.getId(EntityStateHandler.java:81) 
    at org.springframework.data.neo4j.support.mapping.EntityStateHandler.getPersistentState(EntityStateHandler.java:102) 
    at org.springframework.data.neo4j.support.mapping.EntityStateHandler.getPersistentState(EntityStateHandler.java:93) 
    at org.springframework.data.neo4j.support.mapping.EntityStateHandler.getOrCreateRelationship(EntityStateHandler.java:164) 
    at org.springframework.data.neo4j.support.mapping.EntityStateHandler.useOrCreateState(EntityStateHandler.java:139) 
    at org.springframework.data.neo4j.support.mapping.Neo4jEntityConverterImpl.write(Neo4jEntityConverterImpl.java:163) 
    at org.springframework.data.neo4j.support.mapping.Neo4jEntityPersister$CachedConverter.write(Neo4jEntityPersister.java:179) 
    at org.springframework.data.neo4j.support.mapping.Neo4jEntityPersister.persist(Neo4jEntityPersister.java:249) 
    at org.springframework.data.neo4j.support.mapping.Neo4jEntityPersister.persist(Neo4jEntityPersister.java:231) 
    at org.springframework.data.neo4j.support.Neo4jTemplate.save(Neo4jTemplate.java:356) 
    at org.springframework.data.neo4j.support.Neo4jTemplate.save(Neo4jTemplate.java:350) 
    at org.springframework.data.neo4j.repository.AbstractGraphRepository.save(AbstractGraphRepository.java:91) 
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) 
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) 
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) 
    at java.lang.reflect.Method.invoke(Unknown Source) 
    at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.executeMethodOn(RepositoryFactorySupport.java:405) 
    at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.doInvoke(RepositoryFactorySupport.java:390) 
    at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.invoke(RepositoryFactorySupport.java:344) 
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) 
    at org.springframework.transaction.interceptor.TransactionInterceptor$1.proceedWithInvocation(TransactionInterceptor.java:98) 
    at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:262) 
    at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:95) 
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) 
    at org.springframework.dao.support.PersistenceExceptionTranslationInterceptor.invoke(PersistenceExceptionTranslationInterceptor.java:136) 
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) 
    at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:207) 
    at com.sun.proxy.$Proxy49.save(Unknown Source) 
    at neo4j.bakeoff.config.Application.run(Application.java:91) 
    at org.springframework.boot.SpringApplication.runCommandLineRunners(SpringApplication.java:677) 
    ... 5 common frames omitted 

2014-12-19 18:22:50.125 INFO 23660 --- [   main] s.c.a.AnnotationConfigApplicationContext : Closing org.spring[email protected]234b74fd: startup date [Fri Dec 19 18:22:46 EST 2014]; root of context hierarchy 
Exception in thread "main" java.lang.IllegalStateException: Failed to execute CommandLineRunner 
    at org.springframework.boot.SpringApplication.runCommandLineRunners(SpringApplication.java:680) 
    at org.springframework.boot.SpringApplication.afterRefresh(SpringApplication.java:695) 
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:321) 
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:952) 
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:941) 
    at neo4j.bakeoff.config.Application.main(Application.java:109) 
Caused by: java.lang.NullPointerException 
    at org.springframework.data.neo4j.support.mapping.EntityStateHandler.getId(EntityStateHandler.java:81) 
    at org.springframework.data.neo4j.support.mapping.EntityStateHandler.getPersistentState(EntityStateHandler.java:102) 
    at org.springframework.data.neo4j.support.mapping.EntityStateHandler.getPersistentState(EntityStateHandler.java:93) 
    at org.springframework.data.neo4j.support.mapping.EntityStateHandler.getOrCreateRelationship(EntityStateHandler.java:164) 
    at org.springframework.data.neo4j.support.mapping.EntityStateHandler.useOrCreateState(EntityStateHandler.java:139) 
    at org.springframework.data.neo4j.support.mapping.Neo4jEntityConverterImpl.write(Neo4jEntityConverterImpl.java:163) 
    at org.springframework.data.neo4j.support.mapping.Neo4jEntityPersister$CachedConverter.write(Neo4jEntityPersister.java:179) 
    at org.springframework.data.neo4j.support.mapping.Neo4jEntityPersister.persist(Neo4jEntityPersister.java:249) 
    at org.springframework.data.neo4j.support.mapping.Neo4jEntityPersister.persist(Neo4jEntityPersister.java:231) 
    at org.springframework.data.neo4j.support.Neo4jTemplate.save(Neo4jTemplate.java:356) 
    at org.springframework.data.neo4j.support.Neo4jTemplate.save(Neo4jTemplate.java:350) 
    at org.springframework.data.neo4j.repository.AbstractGraphRepository.save(AbstractGraphRepository.java:91) 
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) 
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) 
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) 
    at java.lang.reflect.Method.invoke(Unknown Source) 
    at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.executeMethodOn(RepositoryFactorySupport.java:405) 
    at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.doInvoke(RepositoryFactorySupport.java:390) 
    at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.invoke(RepositoryFactorySupport.java:344) 
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) 
    at org.springframework.transaction.interceptor.TransactionInterceptor$1.proceedWithInvocation(TransactionInterceptor.java:98) 
    at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:262) 
    at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:95) 
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) 
    at org.springframework.dao.support.PersistenceExceptionTranslationInterceptor.invoke(PersistenceExceptionTranslationInterceptor.java:136) 
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) 
    at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:207) 
    at com.sun.proxy.$Proxy49.save(Unknown Source) 
    at neo4j.bakeoff.config.Application.run(Application.java:91) 
    at org.springframework.boot.SpringApplication.runCommandLineRunners(SpringApplication.java:677) 
    ... 5 more

來源

2014-12-19 Dan

爲了使用@RelatedToVia堆棧跟蹤，你需要有兩個已連接的節點，例如用戶，任務。在他們之後，您使用@RelatedToVia添加一個Role屬性。

檢查Spring文檔：http://docs.spring.io/spring-data/neo4j/docs/current/reference/html/

和完整的項目代碼：https://github.com/spring-projects/spring-data-neo4j/tree/master/spring-data-neo4j-examples/cineasts

來源

2015-07-25 09:39:40 christinasantz

正確使用RelationshipEntity

回答

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