spring data 整合

官方文档

代码案例1

pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<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>org.example</groupId>
    <artifactId>springboot-neo4j-learn</artifactId>
    <version>1.0-SNAPSHOT</version>

    <properties>
        <maven.compiler.source>8</maven.compiler.source>
        <maven.compiler.target>8</maven.compiler.target>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    </properties>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.3.0.RELEASE</version>
    </parent>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-neo4j</artifactId>
            <version>2.2.2.RELEASE</version>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
            <exclusions>
                <exclusion>
                    <groupId>org.junit.vintage</groupId>
                    <artifactId>junit-vintage-engine</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

</project>

配置文件

application.properties

spring.data.neo4j.uri=bolt://localhost:7687
spring.data.neo4j.username=neo4j
spring.data.neo4j.password=12345678

实体定义

Person.java

package com.github.houbb.springboot.neo4j.learn.entity;

import lombok.Data;
import org.neo4j.ogm.annotation.*;

/**
 * 创作一个对应 Person 实体对象 -> 对应我们 Neo4j数据库中的 Node 对象
 */
@Data
@NodeEntity("Person")
public class Person {

    @Id
    @GeneratedValue
    private Long id;

    @Property
    @Index(unique = true)
    private String name;

    public Person() {
    }

    public Person(String name) {
        this.name = name;
    }
}

PersonRelationship.java

package com.github.houbb.springboot.neo4j.learn.entity;

import lombok.Data;
import org.neo4j.ogm.annotation.*;

import java.io.Serializable;

@Data
@RelationshipEntity(type = "徒弟")
public class PersonRelation implements Serializable {

    @Id
    @GeneratedValue
    private Long id;

    @StartNode
    private Person parent;

    @EndNode
    private Person child;

    @Property
    private String relation;

    public PersonRelation(Person parent, Person child) {
        this.parent = parent;
        this.child = child;
        this.relation = "徒弟";
    }

}

DAL

PersonRepository.java

package com.github.houbb.springboot.neo4j.learn.dal;

import com.github.houbb.springboot.neo4j.learn.entity.Person;
import org.springframework.data.neo4j.repository.Neo4jRepository;
import org.springframework.stereotype.Repository;

@Repository
public interface PersonRepository extends Neo4jRepository<Person,Long> {
}

PersonRelationRepository.java

package com.github.houbb.springboot.neo4j.learn.dal;

import com.github.houbb.springboot.neo4j.learn.entity.PersonRelation;
import org.springframework.data.neo4j.repository.Neo4jRepository;
import org.springframework.stereotype.Repository;

@Repository
public interface PersonRelationRepository extends Neo4jRepository<PersonRelation,Long> {
}

测试代码

package com.github.houbb.springboot.neo4j.learn.dal;

import com.github.houbb.springboot.neo4j.learn.Application;
import com.github.houbb.springboot.neo4j.learn.entity.Person;
import com.github.houbb.springboot.neo4j.learn.entity.PersonRelation;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringRunner;

@RunWith(SpringRunner.class)
@SpringBootTest(classes = Application.class)
public class SpringbootNeo4jApplicationTests {

    @Autowired
    private PersonRepository personRepository;

    @Autowired
    private PersonRelationRepository personRelationRepository;

    @Test
    public void savePersonTest() {
        Person person = new Person();
        person.setName("老马啸西风");

        personRepository.save(person);
    }

    @Test
    public void savePersonRelationTest() {
        Person personTang = new Person("唐僧");
        Person personSun = new Person("孙悟空");
        Person personZhu = new Person("猪八戒");
        Person personSha = new Person("沙僧");

        // 都是唐僧的徒弟
        PersonRelation pr1 = new PersonRelation(personTang, personSun);
        PersonRelation pr2 = new PersonRelation(personTang, personZhu);
        PersonRelation pr3 = new PersonRelation(personTang, personSha);

        personRelationRepository.save(pr1);
        personRelationRepository.save(pr2);
        personRelationRepository.save(pr3);
    }

}

效果

@Index 唯一索引无效

仅供参考，我正在使用 Neo4j 服务器版本：3.3.6（社区）和 Spring Boot 2。

但是如果我自己在 Neo4j 浏览器中创建约束，它就可以工作。

CREATE CONSTRAINT ON (user:User) ASSERT user.userName IS UNIQUE

Run Code Online (Sandbox Code Playgroud)

有没有办法强制 Spring Data Neo4J 创建独特的属性，而无需自己在数据库中创建它们？

如果您希望应用程序代码创建约束，则需要配置自动索引管理器。

您可以在文档中找到最合适的选项：

https://docs.spring.io/spring-data/neo4j/docs/current/reference/html/#reference :indexing:creation

关于这个主题的注释：想想像 Hibernate 的 DDL 支持一样的自动索引创建。

它是开发时的好帮手。

您不应该在生产环境中使用assertandupdate而只能使用validate.

代码案例2-JPA

整体目录

├─java
│  ├─com
│  │  └─github
│  │      └─houbb
│  │          └─springboot
│  │              └─neo4j
│  │                  └─learn
│  │                      │  Application.java
│  │                      │  package-info.java
│  │                      │
│  │                      ├─controller
│  │                      │      UserController.java
│  └─org
│      └─example
│              Main.java
│
└─resources
        application.properties

pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<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>org.example</groupId>
    <artifactId>springboot-neo4j-learn</artifactId>
    <version>1.0-SNAPSHOT</version>

    <properties>
        <maven.compiler.source>8</maven.compiler.source>
        <maven.compiler.target>8</maven.compiler.target>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    </properties>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.3.0.RELEASE</version>
    </parent>

    <dependencies>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-neo4j</artifactId>
            <version>2.2.2.RELEASE</version>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
            <exclusions>
                <exclusion>
                    <groupId>org.junit.vintage</groupId>
                    <artifactId>junit-vintage-engine</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

</project>

配置文件

application.properties

spring.data.neo4j.uri=bolt://localhost:7687
spring.data.neo4j.username=neo4j
spring.data.neo4j.password=12345678

实体定义

UserNode.java

package com.github.houbb.springboot.neo4j.learn.entity;

import lombok.Data;
import org.neo4j.ogm.annotation.Id;
import org.neo4j.ogm.annotation.NodeEntity;
import org.neo4j.ogm.annotation.Property;

//表示节点类型
@NodeEntity(label="User")
@Data
public class UserNode {

    @Id
    private Long nodeId;

    @Property
    private String userId;

    @Property
    private String name;

    @Property
    private int age;

}

UserRelation.java

package com.github.houbb.springboot.neo4j.learn.entity;

import lombok.Data;
import org.neo4j.ogm.annotation.EndNode;
import org.neo4j.ogm.annotation.Id;
import org.neo4j.ogm.annotation.RelationshipEntity;
import org.neo4j.ogm.annotation.StartNode;

//表示关系类型
@RelationshipEntity(type="UserRelation")
@Data
public class UserRelation {

    @Id
    private Long id;

    @StartNode
    private UserNode startNode;

    @EndNode
    private UserNode endNode;

}

DAL

UserRepository.java

package com.github.houbb.springboot.neo4j.learn.dal;

import com.github.houbb.springboot.neo4j.learn.entity.UserNode;
import org.springframework.data.neo4j.annotation.Query;
import org.springframework.data.neo4j.repository.Neo4jRepository;
import org.springframework.data.repository.query.Param;
import org.springframework.stereotype.Component;

import java.util.List;

@Component
public interface UserRepository extends Neo4jRepository<UserNode,Long> {


    /**
     * 查询所有节点
     * @return
     */
    @Query("MATCH (n:User) RETURN n ")
    List<UserNode> getUserNodeList();

    /**
     * 创建节点
     * @param userId
     * @param name
     * @param age
     * @return
     */
    @Query("create (n:User{userId:$userId,age:$age,name:$name}) RETURN n ")
    List<UserNode> addUserNodeList(@Param("userId") String userId,@Param("name") String name, @Param("age")int age);

}

UserRelationRepository.java

package com.github.houbb.springboot.neo4j.learn.dal;

import com.github.houbb.springboot.neo4j.learn.entity.UserRelation;
import org.springframework.data.neo4j.annotation.Query;
import org.springframework.data.neo4j.repository.Neo4jRepository;
import org.springframework.data.repository.query.Param;
import org.springframework.stereotype.Component;

import java.util.List;

@Component
public interface UserRelationRepository extends Neo4jRepository<UserRelation,Long> {

    /**
     * 通过id 查询关系
     * @param firstUserId
     * @param secondUserId
     * @return
     */
    @Query("match p=(n:User)<-[r:FRIEND]->(n1:User) where n.userId=$firstUserId and n1.userId=$secondUserId return p")
    List<UserRelation> findUserRelationByEachId(@Param("firstUserId") String firstUserId, @Param("secondUserId") String secondUserId);

    /**
     * 添加关系
     * @param firstUserId
     * @param secondUserId
     * @return
     */
    @Query("match (fu:User),(su:User) where fu.userId=$firstUserId and su.userId=$secondUserId create p=(fu)-[r:FRIEND]->(su) return p")
    List<UserRelation> addUserRelation(@Param("firstUserId") String firstUserId, @Param("secondUserId") String secondUserId);

}

service

UserService.java

package com.github.houbb.springboot.neo4j.learn.service;

import com.github.houbb.springboot.neo4j.learn.dal.UserRelationRepository;
import com.github.houbb.springboot.neo4j.learn.dal.UserRepository;
import com.github.houbb.springboot.neo4j.learn.entity.UserNode;
import com.github.houbb.springboot.neo4j.learn.entity.UserRelation;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.List;

@Service
public class UserService {

    @Autowired
    private UserRepository userRepository;

    @Autowired
    private UserRelationRepository userRelationRepository;

    public void addUserNode(UserNode userNode) {
        userRepository.addUserNodeList(userNode.getUserId(),userNode.getName(), userNode.getAge());
    }

    public void addRelationship(String firstId,String secondId){
        userRelationRepository.addUserRelation(firstId,secondId);
    }

    public List<UserRelation> findUserRelationByEachId(String firstId, String secondId){
        return userRelationRepository.findUserRelationByEachId(firstId, secondId);
    }
}

controller

package com.github.houbb.springboot.neo4j.learn.controller;

import com.github.houbb.springboot.neo4j.learn.entity.UserNode;
import com.github.houbb.springboot.neo4j.learn.entity.UserRelation;
import com.github.houbb.springboot.neo4j.learn.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.bind.annotation.RestController;

import java.util.List;

@RestController
public class UserController {

    @Autowired
    private UserService userService;

    /**
     * http://localhost:8080/saveUser
     * @return
     */
    @RequestMapping("/saveUser")
    public String saveUserNode() {

        UserNode node = new UserNode();
        node.setNodeId(1L);
        node.setUserId("2");
        node.setName("赵六");
        node.setAge(26);

        userService.addUserNode(node);

        UserNode node2 = new UserNode();
        node2.setNodeId(2L);
        node2.setUserId("1");
        node2.setName("王五");
        node2.setAge(27);

        userService.addUserNode(node2);
        return "success";
    }

    /**
     * http://localhost:8080/addship
     * @return
     */
    @RequestMapping("/addship")
    public String saveShip(){
        userService.addRelationship("1","2");
        return "success";
    }

    /**
     * http://localhost:8080/findShip
     * @return
     */
    @RequestMapping("/findShip")
    @ResponseBody
    public List<UserRelation> findShip(){
        return userService.findUserRelationByEachId("1","2");
    }

}

测试

http://localhost:8080/saveUser
http://localhost:8080/addship

图数据库中，可以得到【王五】=》【赵六】这样一个关系。

参考资料

Springboot 集成 Neo4j 完整版教程

https://blog.csdn.net/Coder_ljw/article/details/131347272

https://www.baidu.com/link?url=f0vwPTijY6BJO4Eb1IOqeJJR5rm_a_yXnKfrnewr3i9Pjn9zMlfpeSKUH4yZ_LUI&wd=&eqid=d901bc89000179ce000000056539d611

spring data 整合
代码案例1
代码案例2-JPA
- 整体目录
- pom.xml
- 配置文件
- 实体定义
- DAL
- service
- controller
- 测试
参考资料

Neo4j-04-图数据库 neo4j spring-data-neo4j 整合 springboot

spring data 整合

代码案例1

pom.xml

配置文件

实体定义

DAL

测试代码

效果

@Index 唯一索引无效

代码案例2-JPA

整体目录

pom.xml

配置文件

实体定义

DAL

service

controller

测试

参考资料

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