Java Neo4j索引找不到节点
我试图按照文档进行操作,最终得到了Neo4j 1.8的以下代码:Java Neo4j索引找不到节点,java,indexing,nullpointerexception,neo4j,Java,Indexing,Nullpointerexception,Neo4j,我试图按照文档进行操作,最终得到了Neo4j 1.8的以下代码: graphDB = new GraphDatabaseFactory() .newEmbeddedDatabaseBuilder( BASE_FOLDER + NEO4J_PATH ) .newGraphDatabase(); registerShutdownHook(); //Check if there are any indexes System.out.println(A
graphDB = new GraphDatabaseFactory()
.newEmbeddedDatabaseBuilder( BASE_FOLDER + NEO4J_PATH )
.newGraphDatabase();
registerShutdownHook();
//Check if there are any indexes
System.out.println(Arrays.toString(graphDB.index().nodeIndexNames()));
Index<Node> testIndex = graphDB.index().forNodes("test");
Transaction tx = graphDB.beginTx();
try {
String nameKey = "name";
String nameValue = "Gevorg";
//The following 3 lines will be commented out
//when I run the program the second time
Node me = graphDB.createNode();
me.setProperty(nameKey, nameValue);
testIndex.add(me, nameKey, nameValue);
Node meAgain = testIndex.get(nameKey, nameValue).getSingle();
System.out.println(meAgain.getProperty(nameKey));
} finally {
tx.finish();
}
在程序终止后,我对节点/索引的创建进行了注释,并再次运行程序以命中NullPointerException(meAgain为null)。由于程序首先打印
[test]
,然后打印节点meAgain=testIndex.get(nameKey,nameValue).getSingle(),因此正确检索索引代码>检索节点失败。我尝试了使用和不使用事务。我做错了什么???在调用Tx.finish
tx.success()
嗯
/彼得
tx.success()