Neo4j简单的样例

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webport是：7474

三：JAVA操作neo4j

以下样例演示了一个银行层级关系的样例

央行以下有四大行，四大行以下有各自的分行。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以下的支行数据
	 */
	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。把数据库文件夹改为上面的路径，然后，重新启动neo4j

訪问

http://127.0.0.1:7474

输入默认的username/password neo4j/neo4j

然后。改动默认password

就可以查询

以下给几个查询语句

查询全部：match a return a

查询全部标签为'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開始，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開始。往上找三级。一共四级)

总结：neo4j非常适合保存有层级关系的数据，比方说：无限极分类