Using neo4j without magic

[loki2302]

package org.springframework.data.neo4j.examples.hellograph;

import org.neo4j.graphdb.GraphDatabaseService;
import org.neo4j.kernel.EmbeddedGraphDatabase;
import org.springframework.data.neo4j.core.GraphDatabase;
import org.springframework.data.neo4j.repository.GraphRepository;
import org.springframework.data.neo4j.support.DelegatingGraphDatabase;
import org.springframework.data.neo4j.support.Neo4jTemplate;

public class App {
    public static void main( String[] args ) throws Exception {
    	GraphDatabaseService gds = new EmbeddedGraphDatabase("testdb");
    	GraphDatabase gd = new DelegatingGraphDatabase(gds);
    	Neo4jTemplate neo4jTemplate = new Neo4jTemplate(gd);    	
    	neo4jTemplate.postConstruct();
    	
        final GraphRepository<World> repo = neo4jTemplate.repositoryFor(World.class);        
        
        World w = new World("Andrey", 123);
	repo.save(w);
		        
	for(World ww : repo.findAll()) {
		System.out.printf("w[%s,%d]", ww.getName(), ww.getMoons());
	}
    }
}

This says:

Exception in thread "main" org.neo4j.graphdb.NotInTransactionException
	at org.neo4j.kernel.impl.persistence.PersistenceManager.getResource(PersistenceManager.java:252)
	at org.neo4j.kernel.impl.persistence.PersistenceManager.nodeCreate(PersistenceManager.java:155)
	at org.neo4j.kernel.impl.core.NodeManager.createNode(NodeManager.java:213)
	at org.neo4j.kernel.AbstractGraphDatabase.createNode(AbstractGraphDatabase.java:906)
	at org.springframework.data.neo4j.support.DelegatingGraphDatabase.createNode(DelegatingGraphDatabase.java:89)
	at org.springframework.data.neo4j.support.mapping.EntityStateHandler.useOrCreateState(EntityStateHandler.java:131)
	at org.springframework.data.neo4j.support.mapping.Neo4jEntityConverterImpl.write(Neo4jEntityConverterImpl.java:145)
	at org.springframework.data.neo4j.support.mapping.Neo4jEntityPersister$CachedConverter.write(Neo4jEntityPersister.java:176)
	at org.springframework.data.neo4j.support.mapping.Neo4jEntityPersister.persist(Neo4jEntityPersister.java:238)
	at org.springframework.data.neo4j.support.mapping.Neo4jEntityPersister.persist(Neo4jEntityPersister.java:227)
	at org.springframework.data.neo4j.support.Neo4jTemplate.save(Neo4jTemplate.java:311)
	at org.springframework.data.neo4j.repository.AbstractGraphRepository.save(AbstractGraphRepository.java:108)
	at org.springframework.data.neo4j.examples.hellograph.App.main(App.java:20)

How do I make it work?

Spring Data Neo4j version is 2.1.0.BUILD-SNAPSHOT

[loki2302]

It feels like my "how do I make it work" sounds too newbish, so nobody's going to answer :-)
Let me clarify. I just need help making Spring Data Neo4j _externally_ use as little Spring as possible. None of it ideally.

[MichaelHunger]

You can start, stop your transactions manually around the repository methods using Neo4jTemplate

The repositories and other parts of SDN use the Spring stuff heavily though.

If you want to use object-graph-mapping w/o Spring you might want to look into jo4neo.

Transaction tx = neo4jTemplate.beginTx();
try {
   // mutating neo4j operations here & repository methods
   tx.success();
} finally {
   tx.finish();
}

[loki2302]

Thanks for your answer, Michael. Here's the complete code that includes your snippet:

package org.springframework.data.neo4j.examples.hellograph;

import org.neo4j.graphdb.GraphDatabaseService;
import org.neo4j.graphdb.Transaction;
import org.neo4j.kernel.EmbeddedGraphDatabase;
import org.springframework.data.neo4j.core.GraphDatabase;
import org.springframework.data.neo4j.repository.GraphRepository;
import org.springframework.data.neo4j.support.DelegatingGraphDatabase;
import org.springframework.data.neo4j.support.Neo4jTemplate;

public class App {
    public static void main( String[] args ) throws Exception {
    	GraphDatabaseService gds = new EmbeddedGraphDatabase("testdb");
    	GraphDatabase gd = new DelegatingGraphDatabase(gds);
    	Neo4jTemplate neo4jTemplate = new Neo4jTemplate(gd);    	
    	neo4jTemplate.postConstruct();
    	
    	final GraphRepository<World> repo = neo4jTemplate.repositoryFor(World.class);    
        
        Transaction tx = neo4jTemplate.beginTx();
        try {
            World w = new World("Andrey", 123);
            repo.save(w);
    			        
            for(World ww : repo.findAll()) {
              System.out.printf("w[%s,%d]", ww.getName(), ww.getMoons());
            }

            tx.success();
        } finally {
            tx.finish();
        }	    
    }
}

Here's what it says this time:

Exception in thread "main" java.lang.NullPointerException
	at org.springframework.data.neo4j.support.Neo4jTemplate.beginTx(Neo4jTemplate.java:289)
	at org.springframework.data.neo4j.examples.hellograph.App.main(App.java:20)

[MichaelHunger]

Oh, sorry, if you don't use the spring config/PlatformTransactionManager you have to use the underlying Neo4j transaction system the template still uses the Spring-Tx-Manager.

Transaction tx= gds.beginTx();

[loki2302]

Thanks for your support, Michael. After applying your last snippet:

Exception in thread "main" java.lang.NullPointerException
	at org.springframework.data.neo4j.support.mapping.SourceStateTransmitter.getTemplate(SourceStateTransmitter.java:82)
	at org.springframework.data.neo4j.support.mapping.SourceStateTransmitter.copyPropertiesTo(SourceStateTransmitter.java:116)
	at org.springframework.data.neo4j.support.mapping.Neo4jEntityConverterImpl.write(Neo4jEntityConverterImpl.java:149)
	at org.springframework.data.neo4j.support.mapping.Neo4jEntityPersister$CachedConverter.write(Neo4jEntityPersister.java:176)
	at org.springframework.data.neo4j.support.mapping.Neo4jEntityPersister.persist(Neo4jEntityPersister.java:238)
	at org.springframework.data.neo4j.support.mapping.Neo4jEntityPersister.persist(Neo4jEntityPersister.java:227)
	at org.springframework.data.neo4j.support.Neo4jTemplate.save(Neo4jTemplate.java:311)
	at org.springframework.data.neo4j.repository.AbstractGraphRepository.save(AbstractGraphRepository.java:108)
	at org.springframework.data.neo4j.examples.hellograph.App.main(App.java:23)

(line 23 is a call to repo.save(w) )

Any other ideas? :-)