读取JSON密码和Rest API Neo4j时出错

我正试图使用neo4j-REST-graphdb-2.0.0-M06.jar通过java在restapi上执行Cypher查询。从

我使用的java代码是：

RestAPI graphdb1 = new RestAPIFacade(dbpath);
QueryEngine engine1 = new RestCypherQueryEngine(graphdb1);
String cypherQuery= "match (X)-[:rel1]-(Y) where X:LABEL_X and Y:LABEL_Y return X.id,X.name";       
engine1.query(cypherQuery, Collections.EMPTY_MAP);

我得到一个例外：

Exception in thread "main" java.lang.RuntimeException: **Error reading as JSON** ''
    at org.neo4j.rest.graphdb.util.JsonHelper.readJson(JsonHelper.java:57)
    at org.neo4j.rest.graphdb.util.JsonHelper.jsonToSingleValue(JsonHelper.java:62)
    at org.neo4j.rest.graphdb.RequestResult.toEntity(RequestResult.java:114)
    at org.neo4j.rest.graphdb.RequestResult.toMap(RequestResult.java:120)
    at org.neo4j.rest.graphdb.ExecutingRestRequest.toMap(ExecutingRestRequest.java:212)
    at org.neo4j.rest.graphdb.ExecutingRestAPI.query(ExecutingRestAPI.java:544)
    at org.neo4j.rest.graphdb.ExecutingRestAPI.query(ExecutingRestAPI.java:564)
    at org.neo4j.rest.graphdb.RestAPIFacade.query(RestAPIFacade.java:234)
    at org.neo4j.rest.graphdb.query.RestCypherQueryEngine.query(RestCypherQueryEngine.java:50)
    at com.unmetric.graph.test.GraphConnectTest.testRestApi(GraphConnectTest.java:39)
    at com.unmetric.graph.test.GraphConnectTest.main(GraphConnectTest.java:26)
**Caused by: java.io.EOFException: No content to map to Object due to end of input**
    at org.codehaus.jackson.map.ObjectMapper._initForReading(ObjectMapper.java:2775)
    at org.codehaus.jackson.map.ObjectMapper._readMapAndClose(ObjectMapper.java:2718)
    at org.codehaus.jackson.map.ObjectMapper.readValue(ObjectMapper.java:1863)
    at org.neo4j.rest.graphdb.util.JsonHelper.readJson(JsonHelper.java:55)
    ... 10 more

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我遇到了完全相同的问题。经过3个小时的调试，最终发现问题：

RestAPI graphdb1 = new RestAPIFacade(dbpath);

您不仅需要提供dbpath，还需要提供用户名和密码（默认用户名和密码都是neo4j）

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如果在浏览器中执行查询，会发生什么？在neo4j web管理界面中？是的，我得到了结果。我在org.neo4j.rest.graphdb中看到了ExecutingRestApi.class中的代码：公共映射查询（字符串语句，映射参数）{params=（params==null）？Collections.emptyMap（）：params；final RequestResult RequestResult=getRestRequest（）.post（“cypher”，MapUtil.Map（“query”，statement，“params”，params））；return getRestRequest（）.toMap（requestResult）；}这是导致问题的原因吗，方法签名应该改为CypherResult吗？这不意味着响应的实体流是空的或者已经被使用了吗？但这不应该发生，如果你得到一个响应，它应该包含一些实体，不是吗？服务器日志中有什么内容吗？

RestAPI graphdb1 = new RestAPIFacade(dbpath, "neo4j", "neo4j");