Question

尝试连接到Neo4J的java程序我遇到了以下错误

/home/mkgs/Desktop/placement/
Mar 21, 2014 2:53:41 PM org.neo4j.kernel.impl.transaction.xaframework.XaLogicalLog doInternalRecovery
INFO: Non clean shutdown detected on log [/home/mkgs/Desktop/placement/nioneo_logical.log.1Recovery started ...
Mar 21, 2014 2:53:42 PM org.neo4j.kernel.impl.transaction.xaframework.XaLogicalLog doInternalRecovery
INFO: Non clean shutdown detected on log [/home/mkgs/Desktop/placement/index/lucene.log.1]. Recovery started ...
Exception in thread "main" java.lang.ClassCastException: org.neo4j.kernel.TopLevelTransaction cannot be cast to javax.transaction.Transaction
    at neo.main(neo.java:22)

java代码如下

//import javax.transaction.Transaction;

import javax.transaction.Transaction;
import org.neo4j.cypher.ExecutionEngine;
import org.neo4j.cypher.javacompat.ExecutionResult;
import org.neo4j.graphdb.GraphDatabaseService;
import org.neo4j.graphdb.factory.GraphDatabaseFactory;
import org.neo4j.kernel.EmbeddedGraphDatabase;

public class neo {
    public static void main(String args[])
{
    final String DB_PATH = "/home/mkgs/Desktop/placement/";
    GraphDatabaseService graphDb;

    System.out.println(DB_PATH);

    graphDb = new GraphDatabaseFactory().newEmbeddedDatabase(DB_PATH);

    Transaction tx = (Transaction) graphDb.beginTx();

    try  {
        ExecutionEngine engine = new ExecutionEngine(graphDb, null);
        ExecutionResult result = (ExecutionResult) engine.execute("START 
n=node(*) MATCH n-[r]-m RETURN type(r), count(*) ORDER BY count(*) desc");
        System.out.println(result);
    }

    finally {
        ((org.neo4j.graphdb.Transaction) tx).finish();
    }
}
}

Answer 1

不要使用

import javax.transaction.Transaction;

但请使用

import org.neo4j.graphdb.Transaction;

这就是导致ClassCastException。

的原因

java.lang.ClassCastException：org.neo4j.kernel.TopLevelTransaction

1 个答案: