Java操作Neo4J就是这么简单!
Stephen
共 6407字,需浏览 13分钟
·
2022-01-20 14:25
前几天阿粉给大家扩展了关于 Neo4J 图谱数据库的内容,今天阿粉教给大家如何使用 Java 来操作 Neo4j 数据库。
使用 Java 操作 Neo4J
首先我们先使用原生的这种方式,导入 jar 包,然后:
public class TestController {
public static void main(String[] args) {
Driver driver = GraphDatabase.driver("bolt://localhost:7687", AuthTokens.basic("neo4j", "Yinlidong1995."));
Session session = driver.session();
session.run("CREATE (n:Part {name: {name},title: {title}})",
parameters( "name", "Arthur001", "title", "King001" ));
StatementResult result = session.run( "MATCH (a:Part) WHERE a.name = {name} " +
"RETURN a.name AS name, a.title AS title",
parameters( "name", "Arthur001"));
while (result.hasNext()) {
Record record = result.next();
System.out.println( record.get( "title" ).asString() + "" + record.get( "name" ).asString() );
}
session.close();
driver.close();
}
}
这是一种比较古老的方式,来实现的,而且还是需要些 CQL 语句来进行实现。但是胜在非常好理解,这个时候,我们需要再来看看图,看看在 Neo4J 中他是怎么展现的。
通过这个,我们至少证明我们成功连上了,并且创建也成功了。
这时候有细心的读者就会问,为啥我之前在 GraphDatabase.driver
的地方,连接的是
bolt://localhost:7687
.
这是因为,你启动的Neo4J 是7474,也就是说,Neo4J 服务里面可不是这个来连接,
SpringBoot 整合 Neo4j
1.创建SpringBoot项目
常规的创建SpringBoot项目,
创建完成之后,习惯性的要改一下 SpringBoot 的版本号,最好别用最新的,因为阿粉亲身经历,使用最新版的,出现了错误你都不知道怎么出现的,就是这么神奇,你永远都发现不了的bug。
我们把版本号改成2.1.0,这样的话,我们在 pom 文件中加入依赖 jar
org.springframework.boot
spring-boot-starter-data-neo4j
org.projectlombok
lombok
1.16.10
2.增加配置
spring:
data:
neo4j:
url: bolt://localhost:7687
username: neo4j
password: Yinlidong1995.
main:
allow-bean-definition-overriding: true
3.Neo4JConfig
package com.example.neo4j.config;
import org.neo4j.driver.v1.AuthTokens;
import org.neo4j.driver.v1.Driver;
import org.neo4j.driver.v1.GraphDatabase;
import org.neo4j.driver.v1.Session;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.data.neo4j.repository.config.EnableNeo4jRepositories;
import org.springframework.transaction.annotation.EnableTransactionManagement;
@Configuration
@EnableNeo4jRepositories("com.example.neo4j.repository")
@EnableTransactionManagement
public class Neo4jConfig {
@Value("${spring.data.neo4j.url}")
private String url;
@Value("${spring.data.neo4j.username}")
private String userName;
@Value("${spring.data.neo4j.password}")
private String password;
@Bean(name = "session")
public Session neo4jSession() {
Driver driver = GraphDatabase.driver(url, AuthTokens.basic(userName, password));
return driver.session();
}
}
4.编写实体类
package com.example.neo4j.entry;
import org.neo4j.ogm.annotation.*;
import java.util.HashSet;
import java.util.Set;
@NodeEntity("group")
@Data
public class GroupNode {
@Id
@GeneratedValue
private Long id;
/**
* 班级名称
*/
@Property(name = "name")
private String name;
/**
* 编号
*/
private String num;
@Relationship(type = "RelationEdge")
private Set sets = new HashSet<>();
public void addRelation(StudentNode sonNode, String name) {
RelationEdge relationNode = new RelationEdge(this, sonNode, name);
sets.add(relationNode);
sonNode.getSets().add(relationNode);
}
}
学生实体类:
package com.example.neo4j.entry;
import org.neo4j.ogm.annotation.GeneratedValue;
import org.neo4j.ogm.annotation.Id;
import org.neo4j.ogm.annotation.NodeEntity;
import org.neo4j.ogm.annotation.Relationship;
import java.util.HashSet;
import java.util.Set;
/**
* 有点类似于Mysql中的table 映射的对象类,mysql中叫做ORM,neo4j中叫做OGM [object graph mapping]
*/
@NodeEntity("student")
@Data
public class StudentNode {
@Id
@GeneratedValue
private Long id;
/**
* 学生名称
*/
private String name;
/**
* 性别
*/
private String sex;
@Relationship(type = "RelationEdge", direction = "INCOMING")
private Set sets = new HashSet<>();
}
package com.example.neo4j.entry;
import lombok.Data;
import org.neo4j.ogm.annotation.*;
@RelationshipEntity(type = "RelationEdge")
@Data
public class RelationEdge {
@Id
@GeneratedValue
private Long id;
// 关系名
private String name;
@StartNode
private GroupNode groupNode;
@EndNode
private StudentNode studentNode;
public RelationEdge(GroupNode parentNode, StudentNode sonNode, String name) {
this.groupNode = parentNode;
this.studentNode = sonNode;
this.name = name;
}
}
5.Repository接口
对应的学生接口:
package com.example.neo4j.repository;
import com.example.neo4j.entry.StudentNode;
import org.springframework.data.neo4j.repository.Neo4jRepository;
public interface StudentRepository extends Neo4jRepository {
}
对应的班级接口
package com.example.neo4j.repository;
import com.example.neo4j.entry.GroupNode;
import org.springframework.data.neo4j.repository.Neo4jRepository;
public interface GroupRepository extends Neo4jRepository {
}
最后完成编写我们的 Controller
package com.example.neo4j.controller;
import com.example.neo4j.entry.*;
import com.example.neo4j.repository.GroupRepository;
import com.example.neo4j.repository.StudentRepository;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
@RestController
@RequestMapping("/node")
@Slf4j
public class GroupController {
@Autowired
private StudentRepository studentRepository;
@Autowired
private GroupRepository groupRepository;
@GetMapping(value = "/create")
public void createNodeRelation() {
StudentNode studentNode1 = new StudentNode();
studentNode1.setName("Alen");
studentNode1.setSex("男");
StudentNode studentNode2 = new StudentNode();
studentNode2.setName("Kai");
studentNode2.setSex("女");
studentRepository.save(studentNode1);
studentRepository.save(studentNode2);
GroupNode groupNode = new GroupNode();
groupNode.setName("火箭班");
groupNode.setNum("298");
// 增加关系
groupNode.addRelation(studentNode1, "includes");
groupNode.addRelation(studentNode2, "includes");
groupRepository.save(groupNode);
}
}
启动之后,访问http://localhost:8080/node/create
我们再去图谱数据库看看。
怎么样,使用Java 操作是不是也是非常简单的呢?这样的图谱数据库你会选择么?
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