Neo4j 连接字符串

Question

我正在使用 neo4j 作为我的研究论文的图形数据库，我面临着用简单的 jdbc 连接来连接 neo4j2.3.1 的困难。

这是我用来连接到 neo4j 的一个非常简单的代码。

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;

public class Main {
    Main(){
        try {
            Class.forName("org.neo4j.jdbc.Driver");
        }catch (Exception ex){

        }
    }

    public static void main(String[] args) {

        try {
        Connection con = DriverManager.getConnection("jdbc:neo4j://localhost:7474");
        try(Statement stmt = con.createStatement()) {
            ResultSet rs = stmt.executeQuery("MATCH (n:User) RETURN n.name");
            while(rs.next()) {
                System.out.println(rs.getString("n.name"));
            }
        }

        }catch (Exception ex) {
            ex.printStackTrace();
        }
    }
}

这是显示休息身份验证方案存在问题的日志。

> Aug 27, 2015 10:20:25 PM org.neo4j.jdbc.Driver createDatabases INFO:
> Embedded Neo4j support not enabled
> org/neo4j/graphdb/GraphDatabaseService Aug 27, 2015 10:20:25 PM
> org.neo4j.jdbc.Driver createDatabases INFO: Embedded Neo4j support not
> enabled org/neo4j/graphdb/GraphDatabaseService Starting the Apache
> HTTP client Couldn't find any helper support the HTTP_None challenge
> scheme. Unauthorized (401) - Unauthorized     at
> org.restlet.resource.ClientResource.doError(ClientResource.java:612)
>   at
> org.restlet.resource.ClientResource.handleInbound(ClientResource.java:1202)
>   at
> org.restlet.resource.ClientResource.handle(ClientResource.java:1069)
>   at
> org.restlet.resource.ClientResource.handle(ClientResource.java:1044)
>   at
> org.restlet.resource.ClientResource.handle(ClientResource.java:950)
>   at org.restlet.resource.ClientResource.get(ClientResource.java:658)
>   at org.neo4j.jdbc.rest.Resources.readJsonFrom(Resources.java:97)    at
> org.neo4j.jdbc.rest.Resources$DiscoveryClientResource.readInformation(Resources.java:135)
>   at
> org.neo4j.jdbc.rest.Resources.getDiscoveryResource(Resources.java:65)
>   at
> org.neo4j.jdbc.rest.Resources.getDiscoveryResource(Resources.java:60)
>   at
> org.neo4j.jdbc.Neo4jConnection.getDiscoveryResource(Neo4jConnection.java:80)
>   at
> org.neo4j.jdbc.Neo4jConnection.createExecutor(Neo4jConnection.java:69)
>   at org.neo4j.jdbc.Neo4jConnection.<init>(Neo4jConnection.java:61)   at
> org.neo4j.jdbc.Connections$4.doCreate(Connections.java:51)    at
> org.neo4j.jdbc.Connections.create(Connections.java:62)    at
> org.neo4j.jdbc.Driver.connect(Driver.java:64)     at
> org.neo4j.jdbc.Driver.connect(Driver.java:36)     at
> java.sql.DriverManager.getConnection(DriverManager.java:571)
> Unauthorized (401) - Unauthorized at
> java.sql.DriverManager.getConnection(DriverManager.java:233)  at
> Main.main(Main.java:20)   at
> sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)   at
> sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
>   at
> sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
>   at java.lang.reflect.Method.invoke(Method.java:606)     at
> com.intellij.rt.execution.application.AppMain.main(AppMain.java:140)

我使用的是neo4j2.3.1，因为它带有用户名neo4j的默认身份验证。

Answer 1

你需要导入这些neo4j包，

import org.neo4j.jdbc.Driver;
import org.neo4j.jdbc.Neo4jConnection;

然后尝试这些，

Neo4jConnection conn;
ResultSet rs;     

public static void main(String[] args) {
try{
    final Driver driver = new Driver();   //org.neo4j.jdbc.Driver           
    final Properties props = new Properties();
    props.put("user", "your username");
    props.put("password", "your password");   
    String url="jdbc:neo4j://localhost:7474";
    conn = driver.connect(url, props); 

    Statement stmt = conn.createStatement()
    rs = stmt.executeQuery("MATCH (n:User) RETURN n.name");
        while(rs.next()) {
        System.out.println(rs.getString("n.name"));
        }                       
        }
   catch (SQLException e) {
    throw new RuntimeException(e);
    }
}

Answer 2

您需要提供用户和密码作为 JDBC 连接的属性或在连接字符串中。

Properties properties = new Properties();
properties.put("user", "neo4j");
properties.put("password", "neo4j");

serverConnection = DriverManager.getConnection("jdbc:neo4j://localhost:7474", properties);