neo4j的examples之EmbeddedNeo4jWithIndexing.java

neo4j的examples之EmbeddedNeo4jWithIndexing.java

源码：

/* * Licensed to Neo Technology under one or more contributor * license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright * ownership. Neo Technology licenses this file to you under * the Apache License, Version 2.0 (the "License"); you may * not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, * software distributed under the License is distributed on an * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY * KIND, either express or implied. See the License for the * specific language governing permissions and limitations * under the License. */
package org.neo4j.examples;

import java.io.File;
import java.io.IOException;

import org.neo4j.graphdb.GraphDatabaseService;
import org.neo4j.graphdb.Node;
import org.neo4j.graphdb.Transaction;
import org.neo4j.graphdb.factory.GraphDatabaseFactory;
import org.neo4j.graphdb.index.Index;
import org.neo4j.io.fs.FileUtils;

public class EmbeddedNeo4jWithIndexing {
    private static final String DB_PATH = "target/neo4j-store";
    private static final String USERNAME_KEY = "username";
    private static GraphDatabaseService graphDb;
    private static Index<Node> nodeIndex;

    public static void main( final String[] args ) throws IOException
    {
        FileUtils.deleteRecursively( new File( DB_PATH ) );

        // START SNIPPET: startDb
        graphDb = new GraphDatabaseFactory().newEmbeddedDatabase( DB_PATH );
        registerShutdownHook();
        // END SNIPPET: startDb

        // START SNIPPET: addUsers
        try ( Transaction tx = graphDb.beginTx() )
        {
            nodeIndex = graphDb.index().forNodes( "nodes" );
            // Create some users and index their names with the IndexService
            for ( int id = 0; id < 100; id++ )
            {
                createAndIndexUser( idToUserName( id ) );
            }
            // END SNIPPET: addUsers

            // Find a user through the search index
            // START SNIPPET: findUser
            int idToFind = 45;
            String userName = idToUserName( idToFind );
            Node foundUser = nodeIndex.get( USERNAME_KEY, userName ).getSingle();

            System.out.println( "The username of user " + idToFind + " is "
                + foundUser.getProperty( USERNAME_KEY ) );
            // END SNIPPET: findUser

            // Delete the persons and remove them from the index
            for ( Node user : nodeIndex.query( USERNAME_KEY, "*" ) )
            {
                nodeIndex.remove(  user, USERNAME_KEY,
                        user.getProperty( USERNAME_KEY ) );
                user.delete();
            }
            tx.success();
        }
        shutdown();
    }

    private static void shutdown()
    {
        graphDb.shutdown();
    }

    // START SNIPPET: helperMethods
    private static String idToUserName( final int id )
    {
        return "user" + id + "@neo4j.org";
    }

    private static Node createAndIndexUser( final String username )
    {
        Node node = graphDb.createNode();
        node.setProperty( USERNAME_KEY, username );
        nodeIndex.add( node, USERNAME_KEY, username );
        return node;
    }
    // END SNIPPET: helperMethods

    private static void registerShutdownHook()
    {
        // Registers a shutdown hook for the Neo4j and index service instances
        // so that it shuts down nicely when the VM exits (even if you
        // "Ctrl-C" the running example before it's completed)
        Runtime.getRuntime().addShutdownHook( new Thread()
        {
            @Override
            public void run()
            {
                shutdown();
            }
        } );
    }
}

运行结果：

The username of user 45 is user45@neo4j.org

不删除索引：

/* * Licensed to Neo Technology under one or more contributor * license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright * ownership. Neo Technology licenses this file to you under * the Apache License, Version 2.0 (the "License"); you may * not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, * software distributed under the License is distributed on an * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY * KIND, either express or implied. See the License for the * specific language governing permissions and limitations * under the License. */
package n1;
/** * @author xubo601450868 *不删除创建的索引 * * */
import java.io.File;
import java.io.IOException;

import org.neo4j.graphdb.GraphDatabaseService;
import org.neo4j.graphdb.Node;
import org.neo4j.graphdb.Transaction;
import org.neo4j.graphdb.factory.GraphDatabaseFactory;
import org.neo4j.graphdb.index.Index;
import org.neo4j.io.fs.FileUtils;

public class EmbeddedNeo4jWithIndexing {
    private static final String DB_PATH = "target/neo4j-store";
    private static final String USERNAME_KEY = "username";
    private static GraphDatabaseService graphDb;
    private static Index<Node> nodeIndex;

    public static void main( final String[] args ) throws IOException
    {
        FileUtils.deleteRecursively( new File( DB_PATH ) );

        // START SNIPPET: startDb
        graphDb = new GraphDatabaseFactory().newEmbeddedDatabase( DB_PATH );
        registerShutdownHook();
        // END SNIPPET: startDb

        // START SNIPPET: addUsers
        try ( Transaction tx = graphDb.beginTx() )
        {
            nodeIndex = graphDb.index().forNodes( "nodes" );
            // Create some users and index their names with the IndexService
            for ( int id = 0; id < 100; id++ )
            {
                createAndIndexUser( idToUserName( id ) );
            }
            // END SNIPPET: addUsers

            // Find a user through the search index
            // START SNIPPET: findUser
            int idToFind = 45;
            String userName = idToUserName( idToFind );
            Node foundUser = nodeIndex.get( USERNAME_KEY, userName ).getSingle();

            System.out.println( "The username of user " + idToFind + " is "
                + foundUser.getProperty( USERNAME_KEY ) );
            // END SNIPPET: findUser

            // Delete the persons and remove them from the index
            for ( Node user : nodeIndex.query( USERNAME_KEY, "*" ) )
            {
// nodeIndex.remove( user, USERNAME_KEY,
// user.getProperty( USERNAME_KEY ) );
// user.delete();
            }
            tx.success();
        }
        shutdown();
    }

    private static void shutdown()
    {
        graphDb.shutdown();
    }

    // START SNIPPET: helperMethods
    private static String idToUserName( final int id )
    {
        return "user" + id + "@neo4j.org";
    }

    private static Node createAndIndexUser( final String username )
    {
        Node node = graphDb.createNode();
        node.setProperty( USERNAME_KEY, username );
        nodeIndex.add( node, USERNAME_KEY, username );
        return node;
    }
    // END SNIPPET: helperMethods

    private static void registerShutdownHook()
    {
        // Registers a shutdown hook for the Neo4j and index service instances
        // so that it shuts down nicely when the VM exits (even if you
        // "Ctrl-C" the running example before it's completed)
        Runtime.getRuntime().addShutdownHook( new Thread()
        {
            @Override
            public void run()
            {
                shutdown();
            }
        } );
    }
}

查询：

/* * Licensed to Neo Technology under one or more contributor * license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright * ownership. Neo Technology licenses this file to you under * the Apache License, Version 2.0 (the "License"); you may * not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, * software distributed under the License is distributed on an * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY * KIND, either express or implied. See the License for the * specific language governing permissions and limitations * under the License. */

//
package n1;
/** * @author xubo601450868 * 不删除 * 查询所有节点和所有relationship * * */
import java.io.File;
import java.io.IOException;

import org.neo4j.cypher.ExecutionEngine;
import org.neo4j.cypher.ExecutionResult;
import org.neo4j.graphdb.GraphDatabaseService;
import org.neo4j.graphdb.Node;
import org.neo4j.graphdb.factory.GraphDatabaseFactory;
import org.neo4j.io.fs.FileUtils;
import org.neo4j.logging.NullLog;
import org.neo4j.logging.Log;
import org.neo4j.logging.LogProvider;

public class searchByCypher {
    private static final String DB_PATH = "target/neo4j-store";
    private static GraphDatabaseService graphDb;

    private static class MyCustomLogProvider implements LogProvider {
        public MyCustomLogProvider( Object output )
        {
        }

        @Override
        public Log getLog( Class loggingClass )
        {
            return NullLog.getInstance();
        }

        @Override
        public Log getLog( String context )
        {
            return NullLog.getInstance();
        }
    }

    public static void main( final String[] args ) throws IOException
    {
        //FileUtils.deleteRecursively( new File( DB_PATH ) );

        Object output = new Object();

        // START SNIPPET: startDbWithLogProvider
        LogProvider logProvider = new MyCustomLogProvider( output );
        graphDb = new GraphDatabaseFactory().setUserLogProvider( logProvider ).newEmbeddedDatabase( DB_PATH );
        // END SNIPPET: startDbWithLogProvider
        System.out.println("hello neo4j log");
        //Node firstNode;
        //firstNode = graphDb.createNode();
        //firstNode.setProperty( "message", "Hello,scala " );

        ExecutionEngine engine =new ExecutionEngine(graphDb,  logProvider);
         ExecutionResult result = engine.execute("start n=node(*) return n;");  
          System.out.println(result.dumpToString());  

          ExecutionResult result2 = engine.execute("start n=node(*) match (n)-[r]->() return r;");  
          System.out.println(result2.dumpToString());  
        shutdown();
    }

    private static void shutdown()
    {
        graphDb.shutdown();
    }
}

返回结果：

hello neo4j log
+---------------------------------------+
| n |
+---------------------------------------+
| Node[0]{username:"[email protected]"} |
| Node[1]{username:"[email protected]"} |
| Node[2]{username:"[email protected]"} |
| Node[3]{username:"[email protected]"} |
| Node[4]{username:"[email protected]"} |
| Node[5]{username:"[email protected]"} |
| Node[6]{username:"[email protected]"} |
| Node[7]{username:"[email protected]"} |
| Node[8]{username:"[email protected]"} |
| Node[9]{username:"[email protected]"} |
| Node[10]{username:"[email protected]"} |
| Node[11]{username:"[email protected]"} |
| Node[12]{username:"[email protected]"} |
| Node[13]{username:"[email protected]"} |
| Node[14]{username:"[email protected]"} |
| Node[15]{username:"[email protected]"} |
| Node[16]{username:"[email protected]"} |
| Node[17]{username:"[email protected]"} |
| Node[18]{username:"[email protected]"} |
| Node[19]{username:"[email protected]"} |
| Node[20]{username:"[email protected]"} |
| Node[21]{username:"[email protected]"} |
| Node[22]{username:"[email protected]"} |
| Node[23]{username:"[email protected]"} |
| Node[24]{username:"[email protected]"} |
| Node[25]{username:"[email protected]"} |
| Node[26]{username:"[email protected]"} |
| Node[27]{username:"[email protected]"} |
| Node[28]{username:"[email protected]"} |
| Node[29]{username:"[email protected]"} |
| Node[30]{username:"[email protected]"} |
| Node[31]{username:"[email protected]"} |
| Node[32]{username:"[email protected]"} |
| Node[33]{username:"[email protected]"} |
| Node[34]{username:"[email protected]"} |
| Node[35]{username:"[email protected]"} |
| Node[36]{username:"[email protected]"} |
| Node[37]{username:"[email protected]"} |
| Node[38]{username:"[email protected]"} |
| Node[39]{username:"[email protected]"} |
| Node[40]{username:"[email protected]"} |
| Node[41]{username:"[email protected]"} |
| Node[42]{username:"[email protected]"} |
| Node[43]{username:"[email protected]"} |
| Node[44]{username:"[email protected]"} |
| Node[45]{username:"[email protected]"} |
| Node[46]{username:"[email protected]"} |
| Node[47]{username:"[email protected]"} |
| Node[48]{username:"[email protected]"} |
| Node[49]{username:"[email protected]"} |
| Node[50]{username:"[email protected]"} |
| Node[51]{username:"[email protected]"} |
| Node[52]{username:"[email protected]"} |
| Node[53]{username:"[email protected]"} |
| Node[54]{username:"[email protected]"} |
| Node[55]{username:"[email protected]"} |
| Node[56]{username:"[email protected]"} |
| Node[57]{username:"[email protected]"} |
| Node[58]{username:"[email protected]"} |
| Node[59]{username:"[email protected]"} |
| Node[60]{username:"[email protected]"} |
| Node[61]{username:"[email protected]"} |
| Node[62]{username:"[email protected]"} |
| Node[63]{username:"[email protected]"} |
| Node[64]{username:"[email protected]"} |
| Node[65]{username:"[email protected]"} |
| Node[66]{username:"[email protected]"} |
| Node[67]{username:"[email protected]"} |
| Node[68]{username:"[email protected]"} |
| Node[69]{username:"[email protected]"} |
| Node[70]{username:"[email protected]"} |
| Node[71]{username:"[email protected]"} |
| Node[72]{username:"[email protected]"} |
| Node[73]{username:"[email protected]"} |
| Node[74]{username:"[email protected]"} |
| Node[75]{username:"[email protected]"} |
| Node[76]{username:"[email protected]"} |
| Node[77]{username:"[email protected]"} |
| Node[78]{username:"[email protected]"} |
| Node[79]{username:"[email protected]"} |
| Node[80]{username:"[email protected]"} |
| Node[81]{username:"[email protected]"} |
| Node[82]{username:"[email protected]"} |
| Node[83]{username:"[email protected]"} |
| Node[84]{username:"[email protected]"} |
| Node[85]{username:"[email protected]"} |
| Node[86]{username:"[email protected]"} |
| Node[87]{username:"[email protected]"} |
| Node[88]{username:"[email protected]"} |
| Node[89]{username:"[email protected]"} |
| Node[90]{username:"[email protected]"} |
| Node[91]{username:"[email protected]"} |
| Node[92]{username:"[email protected]"} |
| Node[93]{username:"[email protected]"} |
| Node[94]{username:"[email protected]"} |
| Node[95]{username:"[email protected]"} |
| Node[96]{username:"[email protected]"} |
| Node[97]{username:"[email protected]"} |
| Node[98]{username:"[email protected]"} |
| Node[99]{username:"[email protected]"} |
+---------------------------------------+
100 rows

+---+
| r |
+---+
+---+
0 row