I'm working on an webserver project with tomact. I have a dataBase in neo4j. How can I link it to the dataBase? I want to get information from there and also add new data, in the servlets that I created. I tried running the dataBase in the background But i still get "Forbidden (403) - Forbidden" in my project. Do I have to set it somehow? I'm using eclipse, how can I do that?
You can try this approach:
import org.neo4j.graphdb.GraphDatabaseService;
import org.neo4j.graphdb.Node;
import org.neo4j.graphdb.Transaction;
import org.neo4j.graphdb.factory.GraphDatabaseFactory;
// ...
public static void main(String[] args) {
GraphDatabaseFactory graphDbFactory = new GraphDatabaseFactory();
GraphDatabaseService graphDb = graphDbFactory.newEmbeddedDatabase("path_to_neo4j_database/your_database_folder");
try (Transaction tx = graphDb.beginTx()) {
// use graphDb object to manipulate the DB content
tx.success();
}
graphDb.shutdown();
System.out.println("Done :) ");
}
// ...
And don't forget to add the Neo4j library to build path:
Related
I'm beginning in Neo4j java embedded graph.
I have made a first test but I cant visualize my graph in neo4j-community.
Here is my code for creating the graph :
package connection;
import java.io.File;
import org.neo4j.graphdb.GraphDatabaseService;
import org.neo4j.graphdb.Label;
import org.neo4j.graphdb.Node;
import org.neo4j.graphdb.RelationshipType;
import org.neo4j.graphdb.Transaction;
import org.neo4j.graphdb.factory.GraphDatabaseFactory;
public class embededdedGraph {
public static void main(String... args) throws Exception {
GraphDatabaseFactory graphDbFactory = new GraphDatabaseFactory();
File graphDir = new File("/home/nicolas/neo4j-community-3.5.14/data/databases/cars.db");
GraphDatabaseService graphDb = graphDbFactory.newEmbeddedDatabase(graphDir);
Transaction tx = graphDb.beginTx();
createNode(graphDb);
tx.close();
}
public static void createNode(GraphDatabaseService graphDb) {
Node car = graphDb.createNode();
car.addLabel(Label.label("Car"));
car.setProperty("make", "tesla");
car.setProperty("model", "model3");
Node owner = graphDb.createNode(Label.label("Person"));
owner.setProperty("firstName", "Oliver");
owner.setProperty("lastName", "John");
owner.createRelationshipTo(car, RelationshipType.withName("owner"));
}
}
Next I changed the value of "#dbms.active_database" to "dbms.active_database=cars.db in the /neo4j-community-3.5.14/conf/neo4.conf file.
When I restart the neo4j-community, the database name is "cars.db" but it indicated that there are no labels and relationships in it.
What is the problem I cannot figure?
Nicolas
It looks like you need to call tx.success() or tx.fail() before tx.close().
https://neo4j.com/docs/java-reference/3.5/javadocs/org/neo4j/graphdb/Transaction.html
I am also new at this API, I hope it helps
I followed several different tutorials for his but everytime more or less nothing happens. Since I had problems with "ClassNotFoundException" I used the mongodb driver jar file suggested in this question:
Stackoverflow Topic
I have a very simple Java Project with a Class Test running the main method to connect to my database "local" and to the collection "Countries" according to several tutorials, the data should be inserted as defined in the code. But when I check the collection in command line or Studio 3T it is still empty. There are some unused imports due to several tests before.
import org.bson.Document;
import com.mongodb.BasicDBObject;
import com.mongodb.DB;
import com.mongodb.DBCollection;
import com.mongodb.Mongo;
import com.mongodb.MongoClient;
import com.mongodb.client.MongoCollection;
import com.mongodb.client.MongoDatabase;
public class Test {
public static void main(String[] args) {
// TODO Auto-generated method stub
try {
MongoClient connection = new MongoClient("localhost", 27017);
DB db = connection.getDB("local");
DBCollection coll = db.getCollection("Countries");
BasicDBObject doc = new BasicDBObject("title", "MongoDB").
append("name","Germany" ).
append("population", "82 000 000");
coll.insert(doc);
System.out.print("Test");
}
catch(Exception e) {
System.out.print(e);
System.out.print("Test");
}
}
}
The output is the following:
Usage : [--bucket bucketname] action
where action is one of:
list : lists all files in the store
put filename : puts the file filename into the store
get filename1 filename2 : gets filename1 from store and sends to filename2
md5 filename : does an md5 hash on a file in the db (for testing)
I dont get why the insert is not working and in addition why the System.out.print methods are not showing up. The getDB method is also cancelled in eclipse saying "The method getDB(String) from the type Mongo is deprecated" that i do not really understand. I hope someone can help me to get the code working. Mongod.exe is running in the background.
caused by connection reset
I am trying to connect my java program to sql server 20008 r2 through hibernate but i am getting error
main class is as follows
package com.prizm;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;
import org.hibernate.service.ServiceRegistry;
import org.hibernate.service.ServiceRegistryBuilder;
public class SecondPractice {
public static void main(String args[]){
Configuration configuration = new
Configuration().configure("hibernate.cfg.xml");
ServiceRegistryBuilder registry = new ServiceRegistryBuilder();
registry.applySettings(configuration.getProperties());
ServiceRegistry serviceRegistry = registry.buildServiceRegistry();
SessionFactorysessionFactory=configuration.buildSessionFactory(serviceRegistry);
Session session = sessionFactory.openSession();
session.beginTransaction();
Student lecturer = new Student();
lecturer.setFirstname("raj");
lecturer.setLastname("kumar");
session.save(lecturer);
session.getTransaction().commit();
session.close();
}
}
So where i am making mistake, what do i need to know about this error, how to solve it
Thanks in advance
Here i have edited my question and posted the different code from the aforementioned as i am not comfortable with log4J properties so i have tried to connect my java code to database through JDBC , connection is getting done but when it comes about creating any table or any thing else related to data transfer it gives me the same error as i have mentioned.
Here is the code for JDBC along with Logger api of java (java.util.Logger)
package com.prizm;
import java.sql.*;
import java.util.logging.Level;
import java.util.logging.Logger;
import java.util.logging.FileHandler;
import java.util.logging.SimpleFormatter;
public class JKL {
public static Logger logger=Logger.getLogger(JKL.class.getName());
public static FileHandler fh=null;
public static void init(){
try{
fh=new FileHandler("logger.log",false);
}catch(Exception e){}
fh.setFormatter(new SimpleFormatter());
Logger l=Logger.getLogger("");
l.addHandler(fh);
Connection con=null;
try{
DriverManager.registerDriver(new com.microsoft.sqlserver.jdbc.SQLServerDriver());
con=DriverManager.getConnection("jdbc:sqlserver://167.01.09.12;IntegratedSecurity=true");
if(con!=null){
System.out.println("done");
}
Statement st=con.createStatement();
st.executeUpdate("create table hi(id int,name varchar(50))");
}catch(SQLException e){l.log(Level.SEVERE,"Here is your error",e);}
}
public static void main(String args[]){
JKL.init();
}
}
and the log record that i am getting is this
]
so what should i understand from it, do i need to do something with the configuration of microsoft sql server 2008 r2 , as i have sp1 version and this piece of code is working very fine on my friend's computer.
In java 6u29 there was a bug introduced by oracle with bug id : 7103725 which restricts the SSL Connections to SQL Server 2008 and except java version 1.6.0_24 it will give the aforementioned error, to solve this problem we have to pass following property and value to java
-Djsse.enableCBCProtection=false
and as i am using eclipse the steps are as follows
RunAs>>RunConfiguration>>VMArgument and inside the block,copy this property and value, for more detail follow this link.
According to the document of Neo4j, I tried below to create the database using Neo4j Java APIs in Eclipse:
GraphDatabaseService db = new GraphDatabaseFactory().newEmbeddedDatabase("D:/Eclipse/Workplace/test");
and also tried to set the path under the Neo4j folder("D:\Neo4j3.0.1\workplace3"). But I got the same error:
The method newEmbeddedDatabase(File) in the type GraphDatabaseFactory is not applicable for the arguments (String)
Then I tried to import java.io.File; and add:
File dbpath = new File("D:/Neo4j3.0.1/workplace3");
org.neo4j.graphdb.GraphDatabaseService db = dbFactory.newEmbeddedDatabase(dbpath);
then the previous two packages are not used: org.neo4j.graphdb.GraphDatabaseService;, org.neo4j.graphdb.Transaction; But I can compile the program and show "Done successfully" in the Eclipse console.
When I tried to connect to the database using neo4j-ce.exe, it gave me below Alert:
Starting Neo4j failed: Component org.neo4j.server.database.LifecycleManagingDatabase#397b7f" was successfully initialized, but failed to start. Please see attached cause exception.
My code:
package com.peterlan522.neo4j.java.example;
import java.io.File;
import org.neo4j.graphdb.GraphDatabaseService;
import org.neo4j.graphdb.Transaction;
import org.neo4j.graphdb.factory.GraphDatabaseFactory;
import org.neo4j.graphdb.Node;
import org.neo4j.graphdb.Relationship;
import org.neo4j.graphdb.Label;
import org.neo4j.graphdb.RelationshipType;
public class Neo4jJavaAPIDBOperation {
public enum Tutorials implements Label { JAVA, SCALA, SQL, NEO4J,}
public enum TutorialRelationships implements RelationshipType { JVM_LANGIAGES, NON_JVM_LANGIAGES,}
public static void main(String[] args) {
org.neo4j.graphdb.factory.GraphDatabaseFactory dbFactory = new GraphDatabaseFactory();
File dbpath = new File("D:/Neo4j3.0.1/workplace3");
//GraphDatabaseService db = new GraphDatabaseFactory().newEmbeddedDatabase("D:/Eclipse/Workplace/test");
org.neo4j.graphdb.GraphDatabaseService db = dbFactory.newEmbeddedDatabase(dbpath);
try (org.neo4j.graphdb.Transaction tx = db.beginTx()) {
Node javaNode = db.createNode(Tutorials.JAVA);
javaNode.setProperty("TutorialID", "JAVA001");
javaNode.setProperty("Title", "Learn Java");
javaNode.setProperty("NoOfChapters", "25");
javaNode.setProperty("Status", "Completed");
Node scalaNode = db.createNode(Tutorials.SCALA);
scalaNode.setProperty("TutorialID", "SCALA001");
scalaNode.setProperty("Title", "Learn Scala");
scalaNode.setProperty("NoOfChapters", "20");
scalaNode.setProperty("Status", "Completed");
Relationship relationship = javaNode.createRelationshipTo
(scalaNode,TutorialRelationships.JVM_LANGIAGES);
relationship.setProperty("Id","1234");
relationship.setProperty("OOPS","YES");
relationship.setProperty("FP","YES");
tx.success();
}
System.out.print("Done successfully");
}
}
Could anyone help on this? And give executable examples on this. Thank you so much!
Below are the softwares version:
Neo4j community version 3.0.1,
Eclipse Mars(4.5.0),
Java 1.8.0_91,
JRE System Library: JavaSE-1.8
And please get in below link to see the log.txt:
https://drive.google.com/file/d/0B2xDq3--mwK4a0FoanlDengzVWs/view?usp=sharing
I would like to pre-fill and periodically put data to the Google Appengine database.
I would like to write a program in java and python that connect to my GAE service and upload data to my database.
How can I do that?
Thanks
Please use RemoteAPI for doing this programmatically.
In python, you can first configure the appengine_console.py as described here
Once you have that, you can launch and write the following commands in the python shell:
$ python appengine_console.py yourapp
>>> import yourdbmodelclassnamehere
>>> m = yourmodelclassnamehere(x='',y='')
>>> m.put()
And here is code from the java version which is self explanatory (directly borrowed from the remote api page on gae docs):
package remoteapiexample;
import com.google.appengine.api.datastore.DatastoreService;
import com.google.appengine.api.datastore.DatastoreServiceFactory;
import com.google.appengine.api.datastore.Entity;
import com.google.appengine.tools.remoteapi.RemoteApiInstaller;
import com.google.appengine.tools.remoteapi.RemoteApiOptions;
import java.io.IOException;
public class RemoteApiExample {
public static void main(String[] args) throws IOException {
String username = System.console().readLine("username: ");
String password =
new String(System.console().readPassword("password: "));
RemoteApiOptions options = new RemoteApiOptions()
.server("<your app>.appspot.com", 443)
.credentials(username, password);
RemoteApiInstaller installer = new RemoteApiInstaller();
installer.install(options);
try {
DatastoreService ds = DatastoreServiceFactory.getDatastoreService();
System.out.println("Key of new entity is " +
ds.put(new Entity("Hello Remote API!")));
} finally {
installer.uninstall();
}
}
}