系统环境：

Ubuntu 04.10 x64

一：安装

下载最新版：neo4j-community-2.2.3-unix.tar.gz  解压 

cd neo4j-community-2.2.3/bin

./neo4j start

启动之后，默认的web端口是：7474

三：JAVA操作neo4j

下面例子演示了一个银行层级关系的例子

央行下面有四大行，四大行下面有各自的分行，各自的分行又有各自的支行

package com.lala.neo4j;import org.neo4j.graphdb.Label;public class BankLabel implements Label
{private String name;public BankLabel(String name){this.name = name;}public String name() {return name;}
}

package com.lala.neo4j;import org.neo4j.graphdb.RelationshipType;public class BankRelationshipType implements RelationshipType
{private String ship;public BankRelationshipType(String ship){this.ship = ship;}public String name() {return ship;}
}

package com.lala.neo4j;import org.neo4j.graphdb.GraphDatabaseService;
import org.neo4j.graphdb.Node;
import org.neo4j.graphdb.Transaction;
import org.neo4j.graphdb.factory.GraphDatabaseFactory;public class Neo4j 
{/*** 标签*/static BankLabel top = new BankLabel("总行");static BankLabel sdh = new BankLabel("四大银行");static BankLabel fh = new BankLabel("分行");static BankLabel zh = new BankLabel("支行");/*** 关系*/static BankRelationshipType xj = new BankRelationshipType("XJ");static BankRelationshipType sj = new BankRelationshipType("SJ");/*** 初始化总行和分行的关系数据*/static void init1(GraphDatabaseService db)throws Exception{Node n1 = db.createNode(top);n1.setProperty("name", "央行");Node n2 = db.createNode(sdh);n2.setProperty("name", "农业银行");Node n3 = db.createNode(sdh);n3.setProperty("name", "工商银行");n1.createRelationshipTo(n2, sj);n2.createRelationshipTo(n1, xj);n1.createRelationshipTo(n3, sj);n3.createRelationshipTo(n1, xj);}/*** 初始化农业银行分行数据*/static void init2(GraphDatabaseService db)throws Exception{Node n1 = db.getNodeById(1);Node gd = db.createNode(fh);gd.setProperty("name", "农业银行广东分行");n1.createRelationshipTo(gd, sj);gd.createRelationshipTo(n1, xj);Node hn = db.createNode(fh);hn.setProperty("name", "农业银行湖南分行");n1.createRelationshipTo(hn, sj);hn.createRelationshipTo(n1, xj);Node hb = db.createNode(fh);hb.setProperty("name", "农业银行湖北分行");n1.createRelationshipTo(hb, sj);hb.createRelationshipTo(n1, xj);Node zj = db.createNode(fh);zj.setProperty("name", "农业银行浙江分行");n1.createRelationshipTo(zj, sj);zj.createRelationshipTo(n1, xj);}/*** 初始化工商银行分行数据*/static void init3(GraphDatabaseService db)throws Exception{Node n1 = db.getNodeById(2);Node gd = db.createNode(fh);gd.setProperty("name", "工商银行广东分行");n1.createRelationshipTo(gd, sj);gd.createRelationshipTo(n1, xj);Node hn = db.createNode(fh);hn.setProperty("name", "工商银行湖南分行");n1.createRelationshipTo(hn, sj);hn.createRelationshipTo(n1, xj);Node hb = db.createNode(fh);hb.setProperty("name", "工商银行湖北分行");n1.createRelationshipTo(hb, sj);hb.createRelationshipTo(n1, xj);}/*** 初始化农业银行广东分行下面的支行数据*/static void init4(GraphDatabaseService db)throws Exception{Node n1 = db.getNodeById(3);Node th = db.createNode(zh);th.setProperty("name", "农业银行天河支行营业部");n1.createRelationshipTo(th, sj);th.createRelationshipTo(n1, xj);Node yt = db.createNode(zh);yt.setProperty("name", "农业银行燕塘支行");n1.createRelationshipTo(yt, sj);yt.createRelationshipTo(n1, xj);Node thb = db.createNode(zh);thb.setProperty("name", "农业银行天河北路支行");n1.createRelationshipTo(thb, sj);thb.createRelationshipTo(n1, xj);Node sp = db.createNode(zh);sp.setProperty("name", "农业银行石牌东路支行");n1.createRelationshipTo(sp, sj);sp.createRelationshipTo(n1, xj);Node hy = db.createNode(zh);hy.setProperty("name", "农业银行华苑支行");n1.createRelationshipTo(hy, sj);hy.createRelationshipTo(n1, xj);}/*** start a=node(13) MATCH (a)<-[:SJ*1..3]-(b) return a,b (往上找三级，一共四级)* start a=node(1) MATCH (a)-[:SJ*1..3]->(b) return a,b (往下找三级，一共四级)*/public static void main(String[] args) throws Exception{GraphDatabaseService db = new GraphDatabaseFactory().newEmbeddedDatabase("/home/admin/db/neo4j");Transaction tx = db.beginTx();init1(db);init2(db);init3(db);init4(db);tx.success();tx.close();}
}

这里数据的路径是：/home/admin/db/neo4j

cd neo4j-community-2.2.3/conf

vim neo4j-server.properties 文件，把数据库目录改为上面的路径，然后，重启neo4j

访问

http://127.0.0.1:7474

输入默认的用户名/密码 neo4j/neo4j

然后，修改默认密码

即可查询

下面给几个查询语句

查询所有：match a return a

查询所有标签为'分行'的数据 match (a:分行) return a

start a=node(1) MATCH (a)-[:SJ*1..3]->(b) return a,b (从node id=1开始，往下找三级，一共四级)

start a=node(13) MATCH (a)<-[:SJ*1..3]-(b) return a,b (从node id=13开始，往上找三级，一共四级)

总结：neo4j很适合保存有层级关系的数据，比如说：无限极分类