I have installed the community edition 3.5.0-alpha07 of Neo4j and I am trying to create a simple graph containing two nodes following this tutorial. The problem is that the keyword Transaction from org.neo4j.graphdb.Transaction shows syntax error. The code is given below :
Operation.java
import java.io.File;
import org.neo4j.graphdb.GraphDatabaseService;
import org.neo4j.graphdb.Label;
import org.neo4j.graphdb.Node;
import org.neo4j.graphdb.Relationship;
import org.neo4j.graphdb.RelationshipType;
import org.neo4j.graphdb.Transaction;
import org.neo4j.graphdb.factory.GraphDatabaseFactory;
public class Operation {
//private static final File file =new File();
public static void main(String[] args) {
GraphDatabaseFactory dbFactory = new GraphDatabaseFactory();
GraphDatabaseService db= dbFactory.newEmbeddedDatabaseBuilder("C:\\Users\\pritom.mazumdar\\Downloads\\neo4j-community-3.5.0-alpha07\\data\\databases\\graph.db").newGraphDatabase();
//Transaction tx = db.beginTx();
try (Transaction tx = db.beginTx()) {
The resource type Transaction does not implement java.lang.AutoCloseable
Node javaNode = db.createNode();
javaNode.setProperty("TutorialID", "JAVA001");
javaNode.setProperty("Title", "Learn Java");
javaNode.setProperty("NoOfChapters", "25");
javaNode.setProperty("Status", "Completed");
Node scalaNode = db.createNode();
scalaNode.setProperty("TutorialID", "SCALA001");
scalaNode.setProperty("Title", "Learn Scala");
scalaNode.setProperty("NoOfChapters", "20");
scalaNode.setProperty("Status", "Completed");
Relationship relationship = javaNode.createRelationshipTo(scalaNode, (RelationshipType) Label.label("JVM_LANG"));
relationship.setProperty("Id","1234");
relationship.setProperty("OOPS","YES");
relationship.setProperty("FP","YES");
tx.success();
}
System.out.println("Done successfully");
}
}
I have tried implementing AutoCloseable and overriding the close method, but it still doesn't work, the syntax error remians.
It is because try-with-resources Only Accepts AutoClosable Objects. The compiler Says that Transaction is not an AutoClosable.
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 am trying to use Neo4j embedded in Java applications, and I am using this code:
package com.tp.neo4j.java.examples;
import org.neo4j.graphdb.GraphDatabaseService;
import org.neo4j.graphdb.Transaction;
import org.neo4j.graphdb.factory.GraphDatabaseFactory;
public class Neo4jJavaAPIDBOperation {
public static void main(String[] args) {
GraphDatabaseFactory dbFactory = new GraphDatabaseFactory();
GraphDatabaseService db = dbFactory.newEmbeddedDatabase("C:/TPNeo4jDB");
try (Transaction tx = db.beginTx()) {
// Perform DB operations
tx.success();
}
}
}
But I got this Exception:
Exception in thread "main" java.lang.Error: Unresolved compilation problems:
The method newEmbeddedDatabase(File) in the type GraphDatabaseFactory is not applicable for the arguments (String)
Syntax error on token ";", try expected after this token
any idea, please
newEmbeddedDatabase expect File as argument
GraphDatabaseService db = dbFactory.newEmbeddedDatabase(new File("C:/TPNeo4jDB"));
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'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:
I am new to neo4j. I have created a java project in Eclipse to create a neo4j database and some nodes in it. I am seeing the database directory getting created in my workspace folder. But how do i view it on the neo4j browser?
Here is the example code i used :
package com.neo4j.demo;
import org.neo4j.graphdb.GraphDatabaseService;
import org.neo4j.graphdb.Node;
import org.neo4j.graphdb.Relationship;
import org.neo4j.graphdb.Transaction;
import org.neo4j.graphdb.factory.GraphDatabaseFactory;
public class Neo4jDemoOperations {
public static void main(String args[]) {
GraphDatabaseFactory dbFactory = new GraphDatabaseFactory();
GraphDatabaseService db = dbFactory.newEmbeddedDatabase("./DemoDatabase");
try (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.println("Done successfully");
}
}
The Tutorials and TutorialRelationships are enums.
Thanks in advance.
I changed the path to the database in the line
org.neo4j.server.database.location=
in the file neo4j-server.properties inside the conf folder. I chose the path as the path to my database in the workspace folder and it worked!