Question

我有两个@NodeEntity类：

@NodeEntity
class User {
    @GraphId
    Long id;
    String username;
}

@NodeEntity
class Data {
    @GraphId
    Long id;
    String data;
    @RelatedTo(direction=Direction.BOTH)
    User user;
}

还有一个存储库：

@RepositoryRestResource(collectionResourceRel="data", itemResourceRel="data", path="data")
public interface DataRepository  extends GraphRepository<Data> {

//     @Query("MATCH (u:User{username:'danne'}) -- (n:Data) RETURN n")
//     This works in CLI but not here...
    @Query("MATCH (u:User{username:'{username}'}) -- (n:Data) RETURN n")
    public Iterable<Data> findByUsername(@Param("username") String username);
}

为了完全清晰，弹簧靴主......

@ComponentScan
@EnableAutoConfiguration
@EnableNeo4jRepositories
@Configuration
public class SpringBootMain extends Neo4jConfiguration {

    public SpringBootMain() {
        setBasePackage("org.example");
    }

    @Bean
    GraphDatabaseService graphDatabaseService() {
        return new GraphDatabaseFactory().newEmbeddedDatabase("build/test/dataneo4j.db");
    }

    @Autowired
    GraphDatabase graphDatabase;

    public static void main(String[] args) {
        SpringApplication.run(SpringBootMain.class, args);

    }
}

当然，有一个完全像上面的UserRepository，但没有搜索功能。

我尝试使用REST界面curl添加一个User节点和一个连接到它的数据节点。

$ curl -i -H "Content-Type: application/json" -d '{ "username" : "danne" }' -X POST         http://localhost:8080/users
HTTP/1.1 201 Created
Server: Apache-Coyote/1.1
Location: http://localhost:8080/users/1
Content-Length: 0
Date: Tue, 09 Dec 2014 19:34:39 GMT

$ curl -i -H "Content-Type: application/json" -d '{ "data" : "dataA", "user":"http://localhost:8080/users/1"}' -X POST http://localhost:8080/data
HTTP/1.1 201 Created
Server: Apache-Coyote/1.1
Location: http://localhost:8080/data/2
Content-Length: 0
Date: Tue, 09 Dec 2014 19:36:59 GMT

这很好用。通过REST检查一切也看起来很好。

$ curl -i  http://localhost:8080/data
HTTP/1.1 200 OK
Server: Apache-Coyote/1.1
Content-Type: application/hal+json
Transfer-Encoding: chunked
Date: Tue, 09 Dec 2014 19:37:32 GMT

{
  "_links" : {
    "self" : {
      "href" : "http://localhost:8080/data{?page,size,sort}",
      "templated" : true
    },
    "search" : {
      "href" : "http://localhost:8080/data/search"
    }
  },
  "_embedded" : {
    "data" : [ {
      "data" : "dataA",
      "_links" : {
        "self" : {
          "href" : "http://localhost:8080/data/2"
        },
        "user" : {
          "href" : "http://localhost:8080/data/2/user"
        }
      }
    } ]
  },
  "page" : {
    "size" : 20,
    "totalElements" : 1,
    "totalPages" : 1,
    "number" : 0
  }
}

我也可以进入neo4jshell并执行上面注释掉的查询，工作得很好。但是，当访问搜索方法findByUsername时在REST接口上，结果集为空。

查询有什么问题，我需要更改以获取REST接口接受它吗？

Frant Artm建议删除引号，但这并不能让春天开心......

java.lang.NullPointerException: null
at org.neo4j.kernel.TopLevelTransaction.markAsRollbackOnly(TopLevelTransaction.java:93)
at org.neo4j.kernel.TopLevelTransaction.failure(TopLevelTransaction.java:86)
at org.neo4j.cypher.internal.spi.v2_1.TransactionBoundQueryContext.close(TransactionBoundQueryContext.scala:64)
at org.neo4j.cypher.internal.compiler.v2_1.spi.DelegatingQueryContext.close(DelegatingQueryContext.scala:40)
at org.neo4j.cypher.internal.compiler.v2_1.spi.ExceptionTranslatingQueryContext.org$neo4j$cypher$internal$compiler$v2_1$spi$ExceptionTranslatingQueryContext$$super$close(ExceptionTranslatingQueryContext.scala:34)
at org.neo4j.cypher.internal.compiler.v2_1.spi.ExceptionTranslatingQueryContext$$anonfun$close$1.apply$mcV$sp(ExceptionTranslatingQueryContext.scala:34)
at org.neo4j.cypher.internal.compiler.v2_1.spi.ExceptionTranslatingQueryContext$$anonfun$close$1.apply(ExceptionTranslatingQueryContext.scala:34)
at org.neo4j.cypher.internal.compiler.v2_1.spi.ExceptionTranslatingQueryContext$$anonfun$close$1.apply(ExceptionTranslatingQueryContext.scala:34)
at org.neo4j.cypher.internal.compiler.v2_1.spi.ExceptionTranslatingQueryContext.org$neo4j$cypher$internal$compiler$v2_1$spi$ExceptionTranslatingQueryContext$$translateException(ExceptionTranslatingQueryContext.scala:149)
at org.neo4j.cypher.internal.compiler.v2_1.spi.ExceptionTranslatingQueryContext.close(ExceptionTranslatingQueryContext.scala:34)
at org.neo4j.cypher.internal.compiler.v2_1.spi.DelegatingQueryContext.close(DelegatingQueryContext.scala:40)
at org.neo4j.cypher.internal.compiler.v2_1.executionplan.ExecutionWorkflowBuilder$$anonfun$runWithQueryState$1.apply(ExecutionPlanBuilder.scala:165)
at org.neo4j.cypher.internal.compiler.v2_1.executionplan.ExecutionWorkflowBuilder$$anonfun$runWithQueryState$1.apply(ExecutionPlanBuilder.scala:165)
at org.neo4j.cypher.internal.compiler.v2_1.TaskCloser$$anonfun$1.apply(TaskCloser.scala:43)
at org.neo4j.cypher.internal.compiler.v2_1.TaskCloser$$anonfun$1.apply(TaskCloser.scala:41)
at scala.collection.TraversableLike$$anonfun$flatMap$1.apply(TraversableLike.scala:251)
at scala.collection.TraversableLike$$anonfun$flatMap$1.apply(TraversableLike.scala:251)
at scala.collection.immutable.List.foreach(List.scala:318)
at scala.collection.TraversableLike$class.flatMap(TraversableLike.scala:251)
at scala.collection.AbstractTraversable.flatMap(Traversable.scala:105)
at org.neo4j.cypher.internal.compiler.v2_1.TaskCloser.close(TaskCloser.scala:40)
at org.neo4j.cypher.internal.compiler.v2_1.ClosingIterator$$anonfun$close$1.apply$mcV$sp(ClosingIterator.scala:67)
at org.neo4j.cypher.internal.compiler.v2_1.ClosingIterator$$anonfun$close$1.apply(ClosingIterator.scala:67)
at org.neo4j.cypher.internal.compiler.v2_1.ClosingIterator$$anonfun$close$1.apply(ClosingIterator.scala:67)
at org.neo4j.cypher.internal.compiler.v2_1.ClosingIterator$$anonfun$translateException$1.apply(ClosingIterator.scala:72)
at org.neo4j.cypher.internal.compiler.v2_1.ClosingIterator.decoratedCypherException(ClosingIterator.scala:102)
at org.neo4j.cypher.internal.compiler.v2_1.ClosingIterator.translateException(ClosingIterator.scala:70)
at org.neo4j.cypher.internal.compiler.v2_1.ClosingIterator.close(ClosingIterator.scala:66)
at org.neo4j.cypher.internal.compiler.v2_1.ClosingIterator$$anonfun$failIfThrows$1.apply(ClosingIterator.scala:96)
at org.neo4j.cypher.internal.compiler.v2_1.ClosingIterator.decoratedCypherException(ClosingIterator.scala:102)
at org.neo4j.cypher.internal.compiler.v2_1.ClosingIterator.failIfThrows(ClosingIterator.scala:91)
at org.neo4j.cypher.internal.compiler.v2_1.ClosingIterator.hasNext(ClosingIterator.scala:34)
at org.neo4j.cypher.internal.compiler.v2_1.PipeExecutionResult.hasNext(PipeExecutionResult.scala:166)
at scala.collection.Iterator$$anon$11.hasNext(Iterator.scala:327)
at scala.collection.convert.Wrappers$IteratorWrapper.hasNext(Wrappers.scala:29)
at org.neo4j.cypher.internal.compiler.v2_1.PipeExecutionResult$$anon$1.hasNext(PipeExecutionResult.scala:74)
at org.neo4j.helpers.collection.IteratorWrapper.hasNext(IteratorWrapper.java:42)
at org.springframework.data.rest.webmvc.AbstractRepositoryRestController.entitiesToResources(AbstractRepositoryRestController.java:222)
at org.springframework.data.rest.webmvc.AbstractRepositoryRestController.resultToResources(AbstractRepositoryRestController.java:203)
at org.springframework.data.rest.webmvc.RepositorySearchController.executeQueryMethod(RepositorySearchController.java:242)
at org.springframework.data.rest.webmvc.RepositorySearchController.executeSearch(RepositorySearchController.java:146)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at org.springframework.web.method.support.InvocableHandlerMethod.invoke(InvocableHandlerMethod.java:215)
at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:132)
at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:104)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandleMethod(RequestMappingHandlerAdapter.java:749)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:689)
at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:83)
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:938)
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:870)
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:961)
at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:852)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:620)
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:837)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:727)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:77)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:220)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:503)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:170)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:421)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1070)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:611)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1736)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1695)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Thread.java:745)

SOLUTION：

评论中的建议是正确的，引号不应该在那里，和Iterable＆lt;＆gt;需要事务处理，这是一个单独的问题我不会在这里发言。

更改

@Query("MATCH (u:User{username:'{username}'}) -- (n:Data) RETURN n")
public Iterable<Data> findByUsername(@Param("username") String username);

到

@Query("MATCH (u:User{username:{username}}) -- (n:Data) RETURN n")
public Collection<Data> findByUsername(@Param("username") String username);

Answer 1

你不应该在参数周围放置''。 SDN会为您做到这一点。只使用

@Query("MATCH (u:User{username:{username}}) -- (n:Data) RETURN n")
public Iterable<Data> findByUsername(@Param("username") String username);

<强>更新

您还需要将basePackages @EnableNeo4jRepositories设置为包含您的存储库的包

@EnableNeo4jRepositories(basePackages = {"org.example.repositories"})

使用包含您实体的广告

致电setBasePackage

public SpringBootMain() {
    setBasePackage("org.example.entities");
}

来源：

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

示例92.基于Java的配置

Spring Data Neo4j：如何创建工作@Query

1 个答案: