1. 框架搭建

springboot集成知识图谱neo4j

1.1 jar

<dependencies>
     <dependency>
         <groupId>org.springframework.boot</groupId>
         <artifactId>spring-boot-starter</artifactId>
         <exclusions>
             <exclusion>
                 <groupId>org.springframework.boot</groupId>
                 <artifactId>spring-boot-starter-logging</artifactId>
             </exclusion>
         </exclusions>
     </dependency>
     <dependency>
         <groupId>org.springframework.boot</groupId>
         <artifactId>spring-boot-starter-web</artifactId>
     </dependency>
     <!-- neo4j -->
     <dependency>
         <groupId>org.springframework.boot</groupId>
         <artifactId>spring-boot-starter-data-neo4j</artifactId>
     </dependency>
     <dependency>
         <groupId>org.neo4j</groupId>
         <artifactId>neo4j-ogm-http-driver</artifactId>
         <version>3.2.39</version>
     </dependency>
     <!-- 配置 log4j2-->
     <dependency>
         <groupId>org.springframework.boot</groupId>
         <artifactId>spring-boot-starter-log4j2</artifactId>
     </dependency>
     <!-- xml和properties支持 -->
     <dependency>
         <groupId>org.springframework.boot</groupId>
         <artifactId>spring-boot-configuration-processor</artifactId>
         <optional>true</optional>
     </dependency>
     <!-- 验证 -->
     <dependency>
         <groupId>org.springframework.boot</groupId>
         <artifactId>spring-boot-starter-validation</artifactId>
     </dependency>
     <!-- lombok -->
     <dependency>
         <groupId>org.projectlombok</groupId>
         <artifactId>lombok</artifactId>
         <version>1.18.24</version>
         <scope>provided</scope>
     </dependency>
     <!-- 工具类 -->
     <dependency>
         <groupId>org.apache.commons</groupId>
         <artifactId>commons-lang3</artifactId>
         <version>3.12.0</version>
     </dependency>
     <dependency>
         <groupId>org.apache.commons</groupId>
         <artifactId>commons-collections4</artifactId>
         <version>4.4</version>
     </dependency>
     <dependency>
         <groupId>commons-io</groupId>
         <artifactId>commons-io</artifactId>
         <version>2.11.0</version>
     </dependency>
     <dependency>
         <groupId>commons-beanutils</groupId>
         <artifactId>commons-beanutils</artifactId>
         <version>1.9.4</version>
     </dependency>
     <dependency>
         <groupId>com.google.guava</groupId>
         <artifactId>guava</artifactId>
         <version>31.1-jre</version>
     </dependency>
     <!--swagger-->
     <dependency>
         <groupId>com.github.xiaoymin</groupId>
         <artifactId>knife4j-spring-boot-starter</artifactId>
         <version>3.0.3</version>
     </dependency>
     <!-- 常用的编码方法的工具类包 -->
     <dependency>
         <groupId>commons-codec</groupId>
         <artifactId>commons-codec</artifactId>
         <version>1.15</version>
     </dependency>
     <!--log4j-->
     <dependency>
         <groupId>log4j</groupId>
         <artifactId>log4j</artifactId>
         <version>1.2.17</version>
         <scope>test</scope>
     </dependency>
     <dependency>
         <groupId>org.apache.logging.log4j</groupId>
         <artifactId>log4j-web</artifactId>
         <version>2.18.0</version>
     </dependency>
     <!-- validation -->
     <dependency>
         <groupId>javax.validation</groupId>
         <artifactId>validation-api</artifactId>
         <version>2.0.1.Final</version>
     </dependency>
     <!-- fastjson -->
     <dependency>
         <groupId>com.alibaba.fastjson2</groupId>
         <artifactId>fastjson2</artifactId>
         <version>2.0.16</version>
     </dependency>
 </dependencies>

1.2 配置

spring:
  neo4j:
    uri: bolt://127.0.0.1:7687
    security:
      encrypted: false
    authentication:
      username: neo4j
      password: neo4j

2 三种集成方式

2.1 默认接口

使用spring-data提供的接口，返回 @Node 注解的 Bean

2.1.1 定义节点

@Data
@Node("User")
public class UserNode {

    @Id
    private String userId;

    @Relationship(type = "UserCard", direction = Direction.OUTGOING)
    private Set<CardRelation> cardRelation = new HashSet<>();

    public UserNode(String cusNo) {
        this.userId = cusNo;
    }
}

@Data
@Node("Card")
public class CardNode {

    @Id
    private String card;

    public CardNode(String card) {
        this.card = card;
    }
}

2.1.2 定义关系

@Data
@RelationshipProperties
public class CardRelation {

    @RelationshipId
    private Long id;

    private String key;

    private LocalDateTime time;

    @TargetNode
    private CardNode cardNode;

    public CardRelation(String key, LocalDateTime time, CardNode cardNode) {
        this.key = key;
        this.time = time;
        this.cardNode = cardNode;
    }
}

2.1.3 常用接口

2.2 自定义 CypherCql 接口

@Repository
public interface UserRepository extends Neo4jRepository<User, String> {

    @Query(value = "MATCH p=(s:User)-[r]->(t) RETURN p LIMIT $limit")
    List<PathValue> list (Integer limit);

}

2.3 动态拼接 CypherCql

2.3.1 拼接Cql

public RelationshipDto listByCusNo(UserVo vo) {
	String cypher = "MATCH p=(s:User)-[r]-(t) where 1=1 {{where}} RETURN p LIMIT $limit";
	StringBuilder query = new StringBuilder();
	String userId = vo.getUser();
	if (StringUtils.isNotBlank(cusNo)) {
	    query.append(" and s.userId='").append(userId).append("'");
	}
	LocalDateTime time = vo.getTime();
	if (null != time) {
	    query.append(" and r.time >= localdatetime('").append(time).append("') ");
	}
	cypher = StringUtils.replace(cypher, "{{where}}", query.toString());
	Map<String, Object> params = Maps.newHashMap();
	params.put("limit", vo.getLimit());
	log.info("cypher:{}", cypher);
	return neo4jService.selectByCypher(cypher, params);
}

2.3.2 neo4jTemplate 封装

接口

public interface Neo4jService {

    /**
     * @param cypherQuery cypher
     * @return 返回值
     */
    RelationshipDto selectByCypher (String cypherQuery);

    /**
     * @param cypherQuery cypher
     * @param params params
     * @return 返回值
     */
    RelationshipDto selectByCypher (String cypherQuery, Map<String, Object> params);

}

实现类

@Slf4j
@Service
public class Neo4jServiceImpl implements Neo4jService {

    @Resource
    private Neo4jTemplate neo4jTemplate;

    @Override
    public RelationshipDto selectByCypher(String cypherQuery) {
        Map<String, Object> map = Maps.newHashMap();
        return this.selectByCypher(cypherQuery, map);
    }

    @Override
    public RelationshipDto selectByCypher(String cypherQuery, Map<String, Object> params) {
        PreparedQuery<PathValue> condition = PreparedQuery.queryFor(PathValue.class)
                .withCypherQuery(cypherQuery)
                .withParameters(params)
                .build();
        List<PathValue> list = neo4jTemplate.toExecutableQuery(condition).getResults();
        return Neo4jUtil.switchD3(list);
    }
}

工具类 转换D3格式数据

public class Neo4jUtil {

    /**
     * 转换数据格式
     * @param list 查询结果
     * @return D3格式数据
     */
    public static RelationshipDto switchD3 (List<PathValue> list){
        RelationshipDto dto = new RelationshipDto();
        Map<Long, Map<String, Object>> nodeMap = Maps.newHashMap();
        Map<Long, RelationshipDto.EdgeInfo> relationMap = Maps.newHashMap();
        if (CollectionUtils.isNotEmpty(list)) {
            for (PathValue value : list) {
                Path path = value.asPath();
                for (Path.Segment segment : path) {
                    Node start = segment.start();
                    Map<String, Object> startMap = Maps.newHashMap(start.asMap());
                    startMap.put(Constant.NEO4J_ID, start.id());
                    startMap.put(Constant.NEO4J_LABELS, start.labels());
                    nodeMap.putIfAbsent(start.id(), startMap);

                    Node end = segment.end();
                    Map<String, Object> endMap = Maps.newHashMap(end.asMap());
                    endMap.put(Constant.NEO4J_ID, end.id());
                    endMap.put(Constant.NEO4J_LABELS, end.labels());
                    nodeMap.putIfAbsent(end.id(), endMap);

                    Relationship relationship = segment.relationship();
                    Map<String, Object> relMap = Maps.newHashMap(relationship.asMap());
                    relMap.put(Constant.NEO4J_ID, relationship.id());
                    relMap.put(Constant.NEO4J_LABELS, start.labels());
                    RelationshipDto.EdgeInfo edgeInfo = new RelationshipDto.EdgeInfo(start.id(), end.id(), relMap);
                    relationMap.putIfAbsent(relationship.id(), edgeInfo);
                }
            }
            dto.setNodes(Lists.newArrayList(nodeMap.values()));
            dto.setEdges(Lists.newArrayList(relationMap.values()));
        }
        return dto;
    }

}

D3 Bean

@Data
@NoArgsConstructor
@AllArgsConstructor
public class RelationshipDto {

    private List<Map<String, Object>> nodes;
    private List<EdgeInfo> edges;

    @Data
    @AllArgsConstructor
    public static class EdgeInfo{
        private Long source;
        private Long target;
        private Map<String, Object> properties;
    }
}