Springboot集成Neo4j

1、配置文件

Pom 文件中引入依赖 Spring生态中Spring-data部分不仅仅提供了Spring-data-jpa ， 也提供了Spring-data-neo4j 支持spring和 neo4j的完美融合，pom.xml 文件中依赖

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

yml文件中配置连接属性

spring:
  data:
    neo4j:
      uri: bolt://localhost:7687
      username: neo4j
      password: 123
#打印neo4j生成的Cypher
logging:
  level:
    org:
      neo4j:
        ogm:
          drivers:
            bolt:
              request:
                BoltRequest: DEBUG

2、实体类（NodeEntity）

/**
*部门节点实体类
*/
@NodeEntity(label = "Dept")
@Data
@Builder
public class Dept {

    @Id
    @GeneratedValue
    private Long id;

    @Property(name = "deptName")
    private String deptName;

}

/**
*关系 实体类
*/
@RelationshipEntity(type = "relationShip")
@Data
@Builder
public class RelationShip {

    @Id
    @GeneratedValue
    private Long id;

    @StartNode
    private Dept parent;

    @EndNode
    private Dept child;
}

• @NodeEntity： 标明是一个节点实体
• @RelationshipEntity：标明是一个关系实体
• @Id：实体主键
• @Property：实体属性
• @GeneratedValue：实体属性值自增
• @StartNode：开始节点（可以理解为父节点）
• @EndNode：结束节点（可以理解为子节点）

3、创建repositories类（类似于封装过的dao）

@Repository
public interface DeptRepository extends Neo4jRepository<Dept,Long> {

    @Query("MATCH (d:dept) WHERE d.deptName CONTAINS $title RETURN d")
    List<Dept> findByTitle(@Param("title") String title);
}

@Query:编写neo4j 的Cypher语句, 变量格式为$

源码解析：Neo4jRepository.class

@NoRepositoryBean
public interface Neo4jRepository<T, ID extends Serializable> extends PagingAndSortingRepository<T, ID> {
    <S extends T> S save(S var1, int var2);

    <S extends T> Iterable<S> save(Iterable<S> var1, int var2);

    Optional<T> findById(ID var1, int var2);

    Iterable<T> findAll();

    Iterable<T> findAll(int var1);

    Iterable<T> findAll(Sort var1);

    Iterable<T> findAll(Sort var1, int var2);

    Iterable<T> findAllById(Iterable<ID> var1);

    Iterable<T> findAllById(Iterable<ID> var1, int var2);

    Iterable<T> findAllById(Iterable<ID> var1, Sort var2);

    Iterable<T> findAllById(Iterable<ID> var1, Sort var2, int var3);

    Page<T> findAll(Pageable var1);

    Page<T> findAll(Pageable var1, int var2);
}

Neo4jRepository已经经过多层封装，包含了实现了crud基本功能外，再集成了分页功能，之后提炼了常用查询的方法，提高了代码复用性。

4、创建Neo4jConfig配置

package io.fredia.femicro.graph.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.demo.repository")
@EnableTransactionManagement // 激活隐式事务
public class Neo4jConfig {
}

注解解析：@Configuration： springboot声明配置类，一般为单例模式@EnableNeo4jRepositories： Neo4j扫描Repositories所在包，可以理解为mybatis扫描mapper包@EnableTransactionManagement： Neo4j完整的支持ACID，所以此处开启事务功能。
5、编写Service类

@Service
public class DeptService {

    @Autowired
    private DeptRepository deptRepository;

    public Iterable<Dept> saveAll(List<Dept> depts) {
        return deptRepository.saveAll(depts);
    }

    public void deleteById(Long id) {
        deptRepository.deleteById(id);
    }

    public void deleteAll() {
        deptRepository.deleteAll();
    }

    public List<Dept> findByTitle(String title) {
        return deptRepository.findByTitle(title);
    }
}

6、编写Controller类

@RestController
public class TestController {

    @Autowired
    private DeptService deptService;

    @Autowired
    private RelationShipService relationShipService;

    /**
     * CEO
     *    -设计部
     *        - 设计1组
     *        - 设计2组
     *    -技术部
     *        - 前端技术部
     *        - 后端技术部
     *        - 测试技术部
     */
    @GetMapping("/create")
    public void create(){
        Dept CEO = Dept.builder().deptName("CEO").build();
        Dept dept1 = Dept.builder().deptName("设计部").build();
        Dept dept11 = Dept.builder().deptName("设计1组").build();
        Dept dept12 = Dept.builder().deptName("设计2组").build();

        Dept dept2 = Dept.builder().deptName("技术部").build();
        Dept dept21 = Dept.builder().deptName("前端技术部").build();
        Dept dept22 = Dept.builder().deptName("后端技术部").build();
        Dept dept23 = Dept.builder().deptName("测试技术部").build();
        List<Dept> depts = new ArrayList<>(Arrays.asList(CEO,dept1,dept11,dept12,dept2,dept21,dept22,dept23));
        deptService.saveAll(depts);

        RelationShip relationShip1 = RelationShip.builder().parent(CEO).child(dept1).build();
        RelationShip relationShip2 = RelationShip.builder().parent(CEO).child(dept2).build();
        RelationShip relationShip3 = RelationShip.builder().parent(dept1).child(dept11).build();
        RelationShip relationShip4 = RelationShip.builder().parent(dept1).child(dept12).build();
        RelationShip relationShip5 = RelationShip.builder().parent(dept2).child(dept21).build();
        RelationShip relationShip6 = RelationShip.builder().parent(dept2).child(dept22).build();
        RelationShip relationShip7 = RelationShip.builder().parent(dept2).child(dept23).build();
        List<RelationShip> relationShips = new ArrayList<>(Arrays.asList(relationShip1,relationShip2,relationShip3,relationShip4,relationShip5
                ,relationShip6,relationShip7));
        relationShipService.saveAll(relationShips);
    }

    @GetMapping("getById")
    public RelationShip getById(Long id){
        Optional<RelationShip> byId = relationShipService.findById(id);
        return byId.orElse(null);
    }

    @GetMapping("deleteRelationShip")
    public void deleteRelationShip(Long id){
        relationShipService.deleteById(id);
    }

    @GetMapping("deleteDept")
    public void deleteDept(Long id){
        deptService.deleteById(id);
    }

    @GetMapping("deleteAll")
    public void deleteAll(){
        deptService.deleteAll();
        relationShipService.deleteAll();
    }

    @GetMapping("getByTitle")
    public List<Dept> getByTitle(@RequestParam("title") String title){
        return deptService.findByTitle(title);
    }
}

测试结果

启动项目 访问本地地址：实现新增功能

http://localhost:8088/create

登录本机的Neo4j ：localhost：7474

查看Neo4j 数据库内容：

访问本地地址：通过Cypher语句实现查询功能

http://localhost:8088/getByTitle?title=技术

控制台打印日志：

查看Neo4j 数据库内容：