Neo4j+SpringBoot实现节点以及关系的增删改查（Spring Data Neo4j） |
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Neo4j+SpringBoot实现节点以及关系的增删改查（Spring Data Neo4j）
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公司让学习一下Neo4j在SpringBoot框架下的使用，我知道有个Spring DATA Neo4J，在网上找了很多教程，有些地方让我困惑了很久，所以记下来希望能给后面学习的伙伴一些帮助。 先上效果图： IDE：idea JDK：1.8 先搭建一个普通的SpringBoot项目，然后导入依赖。 yml配置： spring: data: neo4j: uri: bolt://localhost:7687 username: neo4j password: cldevpom.xml如下： 4.0.0 org.springframework.boot spring-boot-starter-parent 2.3.2.RELEASE com.example neo4jdemo 0.0.1-SNAPSHOT neo4jdemo Demo project for Spring Boot 1.8 org.springframework.boot spring-boot-starter-data-neo4j org.neo4j neo4j-ogm-core 3.2.14 org.springframework.data spring-data-neo4j 5.3.2.RELEASE com.voodoodyne.jackson.jsog jackson-jsog 1.1 compile org.springframework.boot spring-boot-starter-web org.springframework.boot spring-boot-starter-test test org.junit.vintage junit-vintage-engine org.springframework.boot spring-boot-maven-plugin为了简单，本项目节点只设置一种类型（User），实现的关系的某一个User知道另一User，关系（Know）。 首先编写User节点类（UserNode .java）： package com.example.neo4jdemo.entity.node; import com.fasterxml.jackson.annotation.JsonIdentityInfo; import com.voodoodyne.jackson.jsog.JSOGGenerator; import org.neo4j.ogm.annotation.*; import java.util.HashSet; import java.util.Set; @JsonIdentityInfo(generator= JSOGGenerator.class) @NodeEntity(label = "User") public class UserNode { @Id @GeneratedValue private Long nodeId; @Property(name = "name") private String name; @Property(name = "age") private int age; @Property(name = "sex") private String sex; /*注意这个地方：并不是说加了这个注解，然后下面实现了addKnows这个方法在以后调用addKnows 就可以实现关系的增加，这是不对的，我看了很多教程没有说明。这个addKnows方法，只有在节点未被 添加之前，调用该方法添加关系，然后再调用UserService中的create方法，这样关系才会同时被添加到图 数据库中。如果想实现两个已有节点之间增加关系，需要单独实现*/ @Relationship(type = "know" ,direction = Relationship.OUTGOING) private Set knows = new HashSet(); public Long getNodeId() { return nodeId; } public void setNodeId(Long nodeId) { this.nodeId = nodeId; } public String getName() { return name; } public void setName(String name) { this.name = name; } public int getAge() { return age; } public void setAge(int age) { this.age = age; } public String getSex() { return sex; } public void setSex(String sex) { this.sex = sex; } public Set getKnows() { return knows; } public void setKnows(Set knows) { this.knows = knows; } public Boolean addKnows(UserNode to){ return this.knows.add(to); } @Override public String toString() { return "UserNode{" + "nodeId=" + nodeId + ", name='" + name + '\'' + ", age=" + age + ", sex='" + sex + '\'' + '}'; } public UserNode() {} } 关系类（Know.java） package com.example.neo4jdemo.entity.relationship; import com.example.neo4jdemo.entity.node.UserNode; import com.fasterxml.jackson.annotation.JsonIdentityInfo; import com.voodoodyne.jackson.jsog.JSOGGenerator; import org.neo4j.ogm.annotation.*; /** * @program: neo4jdemo * @description: 知道关系类 * @author: chen * @create: 2020-07-27 **/ @JsonIdentityInfo(generator= JSOGGenerator.class) @RelationshipEntity(type = "know") public class Know { @Id @GeneratedValue private Long id; @StartNode private UserNode from; @EndNode private UserNode to; public Long getId() { return id; } public void setId(Long id) { this.id = id; } public UserNode getFrom() { return from; } public void setFrom(UserNode from) { this.from = from; } public UserNode getTo() { return to; } public void setTo(UserNode to) { this.to = to; } public Know() { } public Know(UserNode from, UserNode to) { this.from = from; this.to = to; } @Override public String toString() { return "Know{" + "id=" + id + ", from=" + from + ", to=" + to + '}'; } } KnowRepository.java package com.example.neo4jdemo.repository; import com.example.neo4jdemo.entity.relationship.Know; import org.springframework.data.neo4j.annotation.Query; import org.springframework.data.neo4j.repository.Neo4jRepository; import org.springframework.data.repository.query.Param; /** * @program: neo4jdemo * @description: 知道关系接口类 * @author: chen * @create: 2020-07-27 **/ public interface KnowRepository extends Neo4jRepository { @Query("MATCH (fromNode) WHERE id(fromNode) = {fromId} MATCH (toNode) WHERE id(toNode) = {toId} MATCH (fromNode)-[r]->(toNode) DELETE r") void deleteByNodeId(@Param(value = "fromId") long fromId,@Param(value = "toId") long toId); } UserRepository.java基础的增删改查Spring Data Neo4j已经封装好在Neo4jRepository里面了。 package com.example.neo4jdemo.repository; import com.example.neo4jdemo.entity.node.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.Repository; @Repository public interface UserRepository extends Neo4jRepository { // @Query("MATCH (n:User) RETURN n ") // List getUserNodeList(); // // @Query("create (n:User{name:{name},age:{age},sex:{sex}}) RETURN n ") // UserNode addUserNode(@Param("name") String name, @Param("age")int age, @Param("sex") String sex); @Query("MATCH (n) WHERE id(n) = :#{#userNode.nodeId} SET n.name = :#{#userNode.name},n.age = :#{#userNode.age},n.sex = :#{#userNode.sex} RETURN n") UserNode updateByNode(@Param("userNode") UserNode userNode); } UserService.java package com.example.neo4jdemo.service; import com.example.neo4jdemo.entity.node.UserNode; import com.example.neo4jdemo.entity.relationship.Know; import java.util.List; import java.util.Optional; public interface UserService { /** * @Description: 添加user节点 * @Params: [UserNode] * @return: int * @Author: chen * @Date: 2020/7/27 */ UserNode create(UserNode userNode); /** * @Description: 删除 * @Author: chen * @Date: 2020/7/27 */ void deleteById(Long id); /** * @Description: 查询 * @Author: chen * @Date: 2020/7/27 * @return */ Optional findById(long id); /** * @Description: 获取所有User节点 * @Params: null * @return: List * @Author: chen * @Date: 2020/7/27 */ List findAll(); /** * @Description: 增加“知道”关系 * @Author: chen * @Date: 2020/7/27 */ Know addIKnows(UserNode fromNode, UserNode toNode); UserNode updateByNode(UserNode userNode); void deleteKnowByNodeId(long fromId,long toId); } UserServiceImpl.java package com.example.neo4jdemo.service.impl; import com.example.neo4jdemo.entity.node.UserNode; import com.example.neo4jdemo.entity.relationship.Know; import com.example.neo4jdemo.repository.KnowRepository; import com.example.neo4jdemo.repository.UserRepository; import com.example.neo4jdemo.service.UserService; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Service; import java.util.List; import java.util.Optional; @Service public class UserServiceImpl implements UserService { @Autowired private UserRepository userRepository; @Autowired private KnowRepository knowRepository; @Override public UserNode create(UserNode userNode) { return userRepository.save(userNode); } @Override public void deleteById(Long id) { userRepository.deleteById(id); } @Override public Optional findById(long id) { return userRepository.findById(id); } @Override public List findAll() { return (List) userRepository.findAll(); } @Override public Know addIKnows(UserNode fromNode, UserNode toNode) { Know newKnow = new Know(fromNode,toNode); return knowRepository.save(newKnow); } @Override public UserNode updateByNode(UserNode userNode) { return userRepository.updateByNode(userNode); } @Override public void deleteKnowByNodeId(long fromId, long toId) { knowRepository.deleteByNodeId(fromId,toId); } } UserController.java package com.example.neo4jdemo.controller; import com.example.neo4jdemo.entity.node.UserNode; import com.example.neo4jdemo.entity.relationship.Know; import com.example.neo4jdemo.service.UserService; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.web.bind.annotation.*; import java.util.List; import java.util.Optional; /** * @program: neo4jdemo * @description: 控制层 * @author: chen * @create: 2020-07-27 **/ @RestController public class UserController { @Autowired private UserService userService; /** * @Description: 添加节点 * @Author: chen * @Date: 2020/7/27 */ @RequestMapping(path = "/add", method = RequestMethod.POST) public UserNode addUserNode(@RequestBody UserNode userNode) { return userService.create(userNode); } /** * @Description: 根据id删除 * @Author: chen * @Date: 2020/7/27 */ @RequestMapping(path = "/delete", method = RequestMethod.POST) public int delUserNodeById(@RequestParam(value = "id") long id) { userService.deleteById(id); System.out.println(id); return 1; } /** * @Description: 根据id更新 * @Author: chen * @Date: 2020/7/27 */ @RequestMapping(path = "/update", method = RequestMethod.POST) public UserNode updateUserNodeByNode(@RequestBody UserNode userNode) { return userService.updateByNode(userNode); } @RequestMapping(path = "/get", method = RequestMethod.GET) public UserNode getUserNodeById(@RequestParam(value = "id") long id) { Optional optionalUserNode = userService.findById(id); if(optionalUserNode.isPresent()){ return optionalUserNode.get(); }else{ return null; } } /** * @Description: 查找所有节点 * @Author: chen * @Date: 2020/7/27 */ @RequestMapping(path = "/list", method = RequestMethod.GET) public List getUserNodeList() { return userService.findAll(); } @RequestMapping(path = "/addKnows", method = RequestMethod.POST) public Know addKnowsById(@RequestParam(value = "from") long fromId, @RequestParam(value = "to") long toId) { Optional fromOpt = userService.findById(fromId); Optional toOpt = userService.findById(toId); if(fromOpt.isPresent()&&toOpt.isPresent()){ return userService.addIKnows(fromOpt.get(),toOpt.get()); }else{ return null; } } @RequestMapping(path = "/delKnows", method = RequestMethod.POST) public String deleteKnowsByNodeId(@RequestParam(value = "from") long fromId, @RequestParam(value = "to") long toId) { Optional fromOpt = userService.findById(fromId); Optional toOpt = userService.findById(toId); if(fromOpt.isPresent()&&toOpt.isPresent()){ userService.deleteKnowByNodeId(fromId,toId); return "ok"; }else{ return "false"; } } } Neo4jConfig.java 我也不知道干啥的 package com.example.neo4jdemo.config; import org.springframework.context.annotation.Configuration; import org.springframework.data.neo4j.repository.config.EnableNeo4jRepositories; import org.springframework.transaction.annotation.EnableTransactionManagement; @Configuration @EnableNeo4jRepositories(basePackages = "com.example.neo4jdemo.repository") @EnableTransactionManagement // 激活SDN隐式事务 public class Neo4jConfig { }重点就是User中的那段注释，是我困扰了很久的问题，希望大家能够避坑。有什么问题可以留言。 |
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