非托管扩展neo4j上的密码查询
[英]cypher query on unmanaged extension neo4j
问题描述
i have an unmanaged extension for my neo4j server. 
我的neo4j服务器有一个不受管的扩展。
and the code like the following. 和如下代码。
@Path("/helloworld")
public class HelloWorldResource {
private final GraphDatabaseService database;
public HelloWorldResource(@Context GraphDatabaseService database) {
this.database = database;
}
@GET
@Produces(MediaType.TEXT_PLAIN)
@Path("/{nodeId}")
public Response hello(@PathParam("nodeId") long nodeId) {
String res = "";
try ( Transaction ignored = database.beginTx();)
{
//@@problem
Result result = database.execute( "MATCH (n:KISI) where id(n)=1 return n" );
} catch (Exception e) {
res = "Error = " + e.getMessage();
}
return Response
.status(Status.OK)
.entity(("nodeId =" + nodeId + " " + res).getBytes(Charset
.forName("UTF-8"))).build();
}
}
When i deploy the code i got 500 internal error. 当我部署代码时，我得到了500个内部错误。 if i remove the code 如果我删除代码
Result result = database.execute( "MATCH (n:KISI) where id(n)=1 return n" );
then everything is fine. 那一切都很好
i checked the log file and the error is the following 我检查了日志文件，错误如下
Aug 13, 2015 3:34:36 AM com.sun.jersey.spi.container.ContainerResponse mapMappableContainerException SEVERE: The exception contained within MappableContainerException could not be mapped to a response, re-throwing to the HTTP container java.lang.NoSuchMethodError: org.neo4j.graphdb.GraphDatabaseService.execute(Ljava/lang/String;)Lorg/neo4j/graphdb/Result;
so whats wrong with my code? 那我的代码怎么了？
1 个解决方案
解决方案1
4 已采纳 2015-08-13 09:05:22
I guess that your Neo4j distribution version and maven dependency version in pom.xml are not same. 我猜您pom.xml中的Neo4j发行版本和maven依赖版本不相同。
But there are several things to check: 但是有几件事要检查：
1) You should always close Result object. 1）您应始终关闭Result对象。 Example: 例：
try(Result result = database.execute( "MATCH (n:KISI) where id(n)=1 return n" )) {
// do stuff here
}
``` ```
2) Exception occurs not in try-catch but later. 2）异常不是在try-catch发生的，而是以后发生的。 You should change your code to this: 您应该将代码更改为此：
try ( Transaction tx = database.beginTx()) {
String query = "MATCH (n:KISI) where id(n)=1 return n";
// use result with try-with-resource to ensure that it will be closed
try(Result result = database.execute(query)) {
// do stuff you need with result here
return Response.ok("nodeId =" + nodeId).build();
}
tx.success(); // mark transaction as successful
} catch (Exception e) {
// If exception occurs - send exception message with 500 status code
// It's good idea to write Exception stacktrace to log there
return Response.serverError().entity(e.getMessage()).build()
}
3) You should check how unmanaged extension .jar file is build. 3）您应该检查非托管扩展.jar文件的构建方式。
- All Neo4j dependencies should be
providedin pom.xml (there are already there in Neo4j distribution).所有Neo4j依赖项都应在pom.xml中provided（Neo4j发行版中已经存在）。 - Check that your database version and your dependency version in pom.xml are same. 检查pom.xml中的数据库版本和依赖版本是否相同。
GraphDatabaseService::executemethod is invented recently (2.2.3 if I remember correctly).GraphDatabaseService::execute方法是最近发明的（如果我没记错的话，请GraphDatabaseService::execute2.2.3）。 Probably your database distribution is older than your maven dependencies.可能您的数据库发行版比您的Maven依赖项还旧。
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