使用来自Java代码的字符串执行密码查询时发生异常

Question

I am trying to insert data to a neo4j graph database. I am trying to create a Person type node whose name is 'Thamali' by using a jersey client. I have given the java code that I use below. I try to execute the cypher query CREATE (thamali:Person {name:"Thamali"}) By using the below java code.

import com.sun.jersey.api.client.Client;
import com.sun.jersey.api.client.ClientResponse;
import com.sun.jersey.api.client.WebResource;
import com.sun.jersey.api.client.filter.HTTPBasicAuthFilter;

import javax.ws.rs.core.MediaType;

public class NeoAPIClass {
    private final String baseUri = "http://localhost:7474/db/data/cypher";
    private final String user = "neo4j";
    private final String password = "12345";

    public static void main(String args[]){
            NeoAPIClass n=new NeoAPIClass();
            n.runQuery();
    }

    void runQuery(){
        Client client = Client.create();
        client.addFilter(new HTTPBasicAuthFilter(user, password));
        WebResource cypherResource = client.resource(baseUri);

        String s="{\"query\":\"CREATE (thamali:Person{name:\"Thamali\"})\"}";
        ClientResponse cypherResponse = cypherResource.accept(MediaType.APPLICATION_JSON)
                .type(MediaType.APPLICATION_JSON_TYPE).entity(s).post(ClientResponse.class);

        System.out.println("Output from Server .... "+ cypherResponse.getStatus());

    }

}

I get the following exception with http status code 500.

    ERROR The exception contained within MappableContainerException could not be mapped to a response, re-throwing to the HTTP container Unexpected character ('T' (code 84)): was expecting comma to separate OBJECT entries [line: 1, column: 41]
    org.neo4j.server.rest.repr.BadInputException: Unexpected character ('T' (code 84)): was expecting comma to separate OBJECT entries [line: 1, column: 41]
        at org.neo4j.server.rest.repr.formats.JsonFormat.readMap(JsonFormat.java:94)
        at org.neo4j.server.rest.web.CypherService.cypher(CypherService.java:89)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:498)
        at com.sun.jersey.spi.container.JavaMethodInvokerFactory$1.invoke(JavaMethodInvokerFactory.java:60)
        at com.sun.jersey.server.impl.model.method.dispatch.AbstractResourceMethodDispatchProvider$ResponseOutInvoker._dispatch(AbstractResourceMethodDispatchProvider.java:205)

Caused by: org.neo4j.server.rest.domain.JsonParseException: Unexpected character ('T' (code 84)): was expecting comma to separate OBJECT entries [line: 1, column: 41]
    at org.neo4j.server.rest.domain.JsonHelper.readJson(JsonHelper.java:73)
    at org.neo4j.server.rest.domain.JsonHelper.jsonToMap(JsonHelper.java:54)
    at org.neo4j.server.rest.repr.formats.JsonFormat.readMap(JsonFormat.java:90)
    ... 43 more

Can anyone please help me to solve this.

Answer 1

Do not call Neo4j REST interface directly. Currently the recommended way to access Neo4j server from java is to use its java driver.

// imports
import org.neo4j.driver.v1.*;
import static org.neo4j.driver.v1.Values.parameters;

// init
Driver driver = GraphDatabase.driver( "bolt://localhost:7687", AuthTokens.basic( "neo4j", "neo4j" ) );

//run query
Session session = driver.session();
session.run( "CREATE (a:Person {name: {name}, title: {title}})",
        parameters( "name", "Arthur", "title", "King" ) );

// destroy
session.close();
driver.close();

See https://neo4j.com/developer/java/#_neo4j_for_java_developers

Answer 2

The problem in the correct formation of the JSON-string. Two ways to solve:

1) Two additional slash to the internal quotation:

String s="{\"query\":\"CREATE (thamali:Person{name:\\\"Thamali\\\"})\"}";

2) Use JSON library. For example by Douglas Crockford :

JSONObject obj = new JSONObject();
obj.put("query", "CREATE (thamali: Person{name:\"Thamali\"})");
String s = obj.toString();