SpringBoot+Thymleaf+Python+Echarts+Neo4j实现知识图谱可视化

方案一：SpringBoot配置多数据源

配置Mysql多数据库

具体可以参考：https://www.w3cschool.cn/article/50807439.html

配置Mysql数据库与Neo4j数据库

参考：https://gitee.com/baomidou/dynamic-datasource-spring-boot-starter
具体如下：

1.引入dynamic-datasource-spring-boot-starter。

<dependency>
  <groupId>com.baomidou</groupId>
  <artifactId>dynamic-datasource-spring-boot-starter</artifactId>
  <version>3.5.1</version>
</dependency>

2.配置数据源。

spring:
  datasource:
    dynamic:
      primary: master #设置默认的数据源或者数据源组,默认值即为master
      strict: false #严格匹配数据源,默认false. true未匹配到指定数据源时抛异常,false使用默认数据源
      datasource:
        master:
          url: jdbc:mysql://xx.xx.xx.xx:3306/dynamic
          username: root
          password: 123456
          driver-class-name: com.mysql.jdbc.Driver # 3.2.0开始支持SPI可省略此配置
        slave_1:
          url: jdbc:neo4j:bolt://192.168.88.1:7687
          username: neo4j
          password: 123
          driver-class-name: org.neo4j.jdbc.bolt.BoltDriver
        slave_2:
          url: ENC(xxxxx) # 内置加密,使用请查看详细文档
          username: ENC(xxxxx)
          password: ENC(xxxxx)
          driver-class-name: com.mysql.jdbc.Driver
          
       #......省略
       #以上会配置一个默认库master，一个组slave下有两个子库slave_1,slave_2

3.使用 @DS 切换数据源。
@DS 可以注解在方法上或类上，同时存在就近原则 方法上注解 优先于 类上注解。

注解	结果
没有@DS	默认数据源
@DS(“dsName”)	dsName可以为组名也可以为具体某个库的名称

@Service
@DS("slave")
public class UserServiceImpl implements UserService {

  @Autowired
  private JdbcTemplate jdbcTemplate;

  public List selectAll() {
    return  jdbcTemplate.queryForList("select * from user");
  }
  
  @Override
  @DS("slave_1")
  public List selectByCondition() {
    return  jdbcTemplate.queryForList("select * from user where age >10");
  }
}

方案二：采用python作为neo4j数据源

思路：通过python获取neo4j数据库数据，将数据写入json文件供SpringBoot访问使用

1、Neo4j数据库数据获取

CyPher语句如下：

MATCH p=(m:Disease)-[r]->(n) return  id(m) as start,labels(m) as mcats,collect(m.name)  as m_name,collect(n.name) as n_name,id(n) as end,labels(n) as ncats,r.name as link limit 20

名称释义:

MATCH p=(m:Disease)-[r]->(n)
提取所有Disease的节点实体有关的关系，节点数据传入p
return id(m) as start
返回m:Disease类型节点的id值，同时赋值别名为start
collect(m.name) as m_name
由于m节点的name属性是多个字符组成的字符串，所以返回时要进行collect组合操作，避免在遍历时赋值不全。
r.name as link
将关系r的name属性赋别名作为link

2、寻找Echarts中关系图Html模板

这里我选择的是：

链接：知识图谱关系图

分析数据结构后，设计的json结构如下

[
	data:{
		node1.name,
		node1.tooltip,
		node1.category
	}，
	{
		node2.name,
		node2.tooltip,
		node2.category
	}
],
[
	link:{
		source:
		target:
		value:
	},
	{
		source:
		target:
		value:
	}
]

3、python将查询cypher语句获得的数据写入json文件

具体参考：

https://blog.csdn.net/luanpeng825485697/article/details/93630060?ops_request_misc=&request_id=&biz_id=102&utm_term=neo4j%E6%9F%A5%E8%AF%A2%E6%9F%90%E4%B8%AA%E5%B1%9E%E6%80%A7cypher&utm_medium=distribute.pc_search_result.none-task-blog-2_blogsobaiduweb~default-8-93630060.nonecase&spm=1018.2226.3001.4450

此处以Neo4j中默认的Movie-Actor数据库为例子说明，用bottle库运行

from py2neo import Graph, Node, Relationship, NodeMatcher

# 连接图库                            初始化账号密码都是neo4j
# graph = Graph('http://localhost:7474', auth=('neo4j', '123'))

# { category: '积极', name: 'cool_polaris', value: 2, symbolSize: 10 }
# { source: '我买不到口罩', target: '野萌君的好朋友', value: 1 },
# 提取实体名称catagory,提取名字name,提取 source-target

import json

from bottle import get, run, request, response, static_file
from py2neo import Graph


#password = {Your neo4j password}
graph = Graph(password = "123")


@get("/")
def get_index():
    return static_file("index.html", root="static")


@get("/graph")
def get_graph():
    results = graph.run(
        "MATCH (m:Movie)<-[:ACTED_IN]-(a:Person) "
        "RETURN m.title as movie, collect(a.name) as cast "
        "LIMIT {limit}", {"limit": 100})
    nodes = []
    rels = []
    i = 0
    print(results)
    for movie, cast in results:
        nodes.append({"title": movie, "label": "movie"})
        target = i
        i += 1
        for name in cast:
            actor = {"name": name, "label": "actor"}
            try:
                source = nodes.index(actor)
            except ValueError:
                nodes.append(actor)
                source = i
                i += 1
            rels.append({"source": source, "target": target,"value":'ACTED_IN'})
    return {"nodes": nodes, "links": rels}


@get("/search")
def get_search():
    try:
        q = request.query["q"]
    except KeyError:
        return []
    else:
        results = graph.run(
            "MATCH (movie:Movie) "
            "WHERE movie.title =~ {title} "
            "RETURN movie", {"title": "(?i).*" + q + ".*"})
        response.content_type = "application/json"
        return json.dumps([{"movie": dict(row["movie"])} for row in results])


@get("/movie/