新建一个maven工程，这里不赘述如何新建maven工程。

添加Neo4j jar到你的工程

有两种方式：

• 上网站官网下载jar包，根据自己的系统下载不同的压缩包，详细过程不描述，请自行搜索其他博客
• 通过maven获得jar包，本文将详细介绍这个方法

pom.xml文件下添加dependency

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"><modelVersion>4.0.0</modelVersion><groupId>nd.esp.com</groupId><artifactId>MyNeo4j</artifactId><version>0.0.1-SNAPSHOT</version><packaging>jar</packaging><name>MyNeo4j</name><url>http://maven.apache.org</url><properties><project.build.sourceEncoding>UTF-8</project.build.sourceEncoding></properties><!-- Embedded Neo4j依赖，目前最新版本是2.3.3--><dependencies><dependency><groupId>org.neo4j</groupId><artifactId>neo4j-slf4j</artifactId><version>2.3.3</version></dependency></dependencies>
</project>

Hello World 程序

代码可以在github上看到：https://github.com/neo4j/neo4j/blob/2.3.3/community/embedded-examples/src/main/java/org/neo4j/examples/EmbeddedNeo4j.java

/** 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.Direction;
import org.neo4j.graphdb.GraphDatabaseService;
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;
import org.neo4j.io.fs.FileUtils;public class EmbeddedNeo4j
{// Embedded Neo4j会在本地产生一个文件夹(类似于Mysql的数据库)private static final String DB_PATH = "target/neo4j-hello-db";public String greeting;// START SNIPPET: varsGraphDatabaseService graphDb;Node firstNode;Node secondNode;Relationship relationship;// END SNIPPET: vars// START SNIPPET: createReltypeprivate static enum RelTypes implements RelationshipType{KNOWS}// END SNIPPET: createReltypepublic static void main( final String[] args ) throws IOException{EmbeddedNeo4j hello = new EmbeddedNeo4j();hello.createDb();// 删除数据hello.removeData();hello.shutDown();}void createDb() throws IOException{FileUtils.deleteRecursively( new File( DB_PATH ) );// START SNIPPET: startDbgraphDb = new GraphDatabaseFactory().newEmbeddedDatabase( DB_PATH );registerShutdownHook( graphDb );// END SNIPPET: startDb// START SNIPPET: transaction// Embedded Neo4j基本上所有的操作都需要在事务内执行try ( Transaction tx = graphDb.beginTx() ){// Database operations go here// END SNIPPET: transaction// START SNIPPET: addDatafirstNode = graphDb.createNode();firstNode.setProperty( "message", "Hello, " );secondNode = graphDb.createNode();secondNode.setProperty( "message", "World!" );relationship = firstNode.createRelationshipTo( secondNode, RelTypes.KNOWS );relationship.setProperty( "message", "brave Neo4j " );// END SNIPPET: addData// START SNIPPET: readDataSystem.out.print( firstNode.getProperty( "message" ) );System.out.print( relationship.getProperty( "message" ) );System.out.print( secondNode.getProperty( "message" ) );// END SNIPPET: readDatagreeting = ( (String) firstNode.getProperty( "message" ) )+ ( (String) relationship.getProperty( "message" ) )+ ( (String) secondNode.getProperty( "message" ) );// START SNIPPET: transactiontx.success();}// END SNIPPET: transaction}// 移除新建的数据void removeData(){try ( Transaction tx = graphDb.beginTx() ){// START SNIPPET: removingData// let's remove the datafirstNode.getSingleRelationship( RelTypes.KNOWS, Direction.OUTGOING ).delete();firstNode.delete();secondNode.delete();// END SNIPPET: removingDatatx.success();}}// 关闭Neo4j 数据库void shutDown(){System.out.println();System.out.println( "Shutting down database ..." );// START SNIPPET: shutdownServergraphDb.shutdown();// END SNIPPET: shutdownServer}// 为Neo4j 实例注册一个关闭的hook，当VM被强制退出时，Neo4j 实例能够正常关闭private static void registerShutdownHook( final GraphDatabaseService graphDb ){// Registers a shutdown hook for the Neo4j instance so that it// shuts down nicely when the VM exits (even if you "Ctrl-C" the// running application).Runtime.getRuntime().addShutdownHook( new Thread(){@Overridepublic void run(){graphDb.shutdown();}} );}
}

在事务中操作

所有的操作都必须在一个事务中完成。这是官方一个刻意的设计，因为他们坚信事务划分是企业型数据库重要的一部分。所以，你可以使用如下的方式开启事务：

try ( Transaction tx = graphDb.beginTx() ){// Database operations go heretx.success();
}

try(){}这种语法是在jdk1.7之后支持的，这种方式能够让vm支持自动释放使用结束的资源。在这里可以不需要自己调用语句:

finally{tx.close();
}

如果你使用低于jdk1.7以后的版本，可以修改为如下的代码：

Transaction tx = graphDb.beginTx()
try{// Database operations go heretx.success();
}finally{tx.close();
}

创建一个简单的图

使用一下代码创建两个节点和一个关系：

firstNode = graphDb.createNode();
firstNode.setProperty( "message", "Hello, " );
secondNode = graphDb.createNode();
secondNode.setProperty( "message", "World!" );relationship = firstNode.createRelationshipTo( secondNode, RelTypes.KNOWS );
relationship.setProperty( "message", "brave Neo4j " );

创建之后的图数据如下：

本文翻译自官网使用手册：http://neo4j.com/docs/stable/tutorials-java-embedded-hello-world.html

教程结束，感谢阅读。
欢迎转载，但请注明本文链接，谢谢。
2016/4/5 20:09:25