00 概述

本文总结了Neo4j和Spring/SpringBoot、Alibaba Druid、Dynamic Datasource、Mybatis等整合方案，对相应配置做了详细说明。

01 Spring Data Neo4j 整合方案

---

添加Neo4j JDBC Driver依赖

<!--Neo4j-Jdbc-Driver-->
<dependency>
    <groupId>org.neo4j</groupId>
    <artifactId>neo4j-jdbc-driver</artifactId>
    <version>4.0.5</version>
</dependency>

添加application.yml配置

spring:
    neo4j:
      uri: bolt://localhost:7687 # neo4j+s://xxx.xxx.xxx
      authentication:
        username: neo4j
        password: root

02 Alibaba Druid 整合方案

---

添加Neo4j JDBC Driver + Alibaba Druid依赖

<!--Neo4j-Jdbc-Driver-->
<dependency>
    <groupId>org.neo4j</groupId>
    <artifactId>neo4j-jdbc-driver</artifactId>
    <version>4.0.5</version>
</dependency>
<!--Druid-->
<dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>druid-spring-boot-starter</artifactId>
    <version>1.2.12</version>
</dependency>

添加application.yml配置

spring:
    datasource:
      type: com.alibaba.druid.pool.DruidDataSource
      driverClassName: org.neo4j.jdbc.Driver
      url: jdbc:neo4j:bolt://localhost:7687 #jdbc:neo4j:neo4j+s://xxx.xxx.xxx
      username: neo4j
      password: root

03 Dynamic Datasource 多数据源整合方案

---

添加Neo4j JDBC Driver、Alibaba Druid、Dynamic DataSource依赖

<!--Neo4j-Jdbc-Driver-->
<dependency>
    <groupId>org.neo4j</groupId>
    <artifactId>neo4j-jdbc-driver</artifactId>
    <version>4.0.5</version>
</dependency>
<!--Druid-->
<dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>druid-spring-boot-starter</artifactId>
    <version>1.2.12</version>
</dependency>
<!-- Dynamic DataSource -->
<dependency>
    <groupId>com.baomidou</groupId>
    <artifactId>dynamic-datasource-spring-boot-starter</artifactId>
    <version>3.5.2</version>
</dependency>
<!--Mybatis SpringBoot-->
<dependency>
    <groupId>org.mybatis.spring.boot</groupId>
    <artifactId>mybatis-spring-boot-starter</artifactId>
    <version>2.2.2</version>
</dependency>

添加application.yml配置

spring:
  datasource:
    druid:
      initialSize: 5
      minIdle: 5
      maxActive: 20
      maxWait: 60000
      timeBetweenEvictionRunsMillis: 60000
      minEvictableIdleTimeMillis: 300000
      testOnBorrow: false
      testOnReturn: false
      poolPreparedStatements: true
      filters: stat,wall,slf4j
      maxPoolPreparedStatementPerConnectionSize: 20
      useGlobalDataSourceStat: true
      connectionProperties: druid.stat.mergeSql=true;druid.stat.slowSqlMillis=500
    dynamic:
      datasource:
        # Mysql Datasource
        master:
          driver-class-name: com.mysql.cj.jdbc.Driver
          url: jdbc:mysql://127.0.0.1:3306/master
          username: root
          password: root
        # Neo4j Datasource
        neo4j:
          driver-class-name: org.neo4j.jdbc.Driver
          url: jdbc:neo4j:bolt://localhost:7687 #jdbc:neo4j:neo4j+s://xxx.xxx.xxx
          username: neo4j
          password: root
  # Neo4j Setting
  neo4j:
    uri: bolt://localhost:7687 #neo4j+s://xxx.xxx.xxx
    authentication:
      username: neo4j
      password: root

Mapper中加入数据源注解：@DS("neo4j")

@DS("neo4j")
@Repository
public interface Neo4jTestMapper {
    List<SysDept> selectMovies();
}

Mapper.xml

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.kevinwong.mapper.Neo4jTestMapper">

    <select id="selectMovies" resultType="MovieInfo">
        MATCH (people:Movie)
        RETURN
          id(people) as id,
          people.title as title,
          people.tagline as tagline,
          people.released as released LIMIT 10
    </select>

</mapper>

查询日志：

JDBC Connection [com.baomidou.dynamic.datasource.tx.ConnectionProxy@501a99e2] will not be managed by Spring
==>  Preparing: MATCH (people:Movie) RETURN id(people) as id, people.title as title, people.tagline as tagline, people.released as released LIMIT 10
==> Parameters: 
<==    Columns: id, title, tagline, released
<==        Row: 0, The Matrix, Welcome to the Real World, 1999
<==        Row: 9, The Matrix Reloaded, Free your mind, 2003
.........

<==        Row: 56, What Dreams May Come, After life there is more. The end is just the beginning., 1998
<==      Total: 10
Committing JDBC Connection [com.baomidou.dynamic.datasource.tx.ConnectionProxy@501a99e2]

04 注意事项

---

1.datasource中driver的配置

本文driverClassName配置为org.neo4j.jdbc.Driver，方便在uri变化时自动匹配不同driver。neo4j-jdbc-driver提供了HttpDriver、BoltDriver、BoltRoutingNeo4jDriver三种不同Scheme下的驱动，uri前缀不同时需要配置相应的driver，配置出错会产生连接异常。org.neo4j.jdbc.Driver下初始化了三种driver，根据uri配置的前缀自动匹配。

static {
    DRIVERS.put("^neo4j(\\+s|\\+ssc)?$", BoltRoutingNeo4jDriver.class);
    DRIVERS.put("^bolt(\\+s|\\+ssc)?$", BoltDriver.class);
    DRIVERS.put("http[s]?", HttpDriver.class);
}

2.Dynamic Datasource 多数据源的配置

在多数据源配置中，在spring.dynamic.datasource下配置了neo4j数据源， 仍然配置了spring.neo4j相关参数，主要原因为Neo4jDriver会在启动时进行健康检查，如果不配置会产生健康检查失败告警：WARN o.s.b.actuate.neo4j.Neo4jReactiveHealthIndicator - Health check failed

2022-10-10 10:10:00 [Neo4jDriverIO-2-3] WARN  o.s.b.actuate.neo4j.Neo4jReactiveHealthIndicator - Health check failed 
org.neo4j.driver.exceptions.AuthenticationException: Unsupported authentication token, scheme='none' only allowed when auth is disabled: { scheme='none', user_agent='neo4j-java/dev' }
at org.neo4j.driver.internal.util.ErrorUtil.newNeo4jError(ErrorUtil.java:76)
at org.neo4j.driver.internal.async.inbound.InboundMessageDispatcher.handleFailureMessage(InboundMessageDispatcher.java:122)
    .........

at org.neo4j.driver.internal.shaded.io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)
at java.lang.Thread.run(Thread.java:750)
Suppressed: org.neo4j.driver.exceptions.ServiceUnavailableException: Connection to the database terminated. Please ensure that your database is listening on the correct host and port and that you have compatible encryption settings both on Neo4j server and driver. Note that the default encryption setting has changed in Neo4j 4.0.
at org.neo4j.driver.internal.util.ErrorUtil.newConnectionTerminatedError(ErrorUtil.java:56)
    .........