Springboot+springDataNeo4j 整合记录 (一) 并解决java.lang.NullPointerException_springboot langchain4j

linux 安装Neo4J

项目集成比较完美的教程

下面就是花了好长时间解决的空指针问题

java.lang.NullPointerException: null
	at org.neo4j.ogm.metadata.MetaData.entityType(MetaData.java:296) ~[neo4j-ogm-core-3.1.11.jar:3.1.11]
	at org.neo4j.ogm.session.Neo4jSession.entityType(Neo4jSession.java:642) ~[neo4j-ogm-core-3.1.11.jar:3.1.11]
	at org.neo4j.ogm.session.delegates.LoadByTypeDelegate.loadAll(LoadByTypeDelegate.java:72) ~[neo4j-ogm-core-3.1.11.jar:3.1.11]
	at org.neo4j.ogm.session.delegates.LoadByTypeDelegate.loadAll(LoadByTypeDelegate.java:159) ~[neo4j-ogm-core-3.1.11.jar:3.1.11]
	at org.neo4j.ogm.session.Neo4jSession.loadAll(Neo4jSession.java:273) ~[neo4j-ogm-core-3.1.11.jar:3.1.11]
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_181]
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[?:1.8.0_181]
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:1.8.0_181]
	at java.lang.reflect.Method.invoke(Method.java:498) ~[?:1.8.0_181]
	at org.springframework.util.ReflectionUtils.invokeMethod(ReflectionUtils.java:282) ~[spring-core-5.1.9.RELEASE.jar:5.1.9.RELEASE]
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看了源码是实体类没有映射
解决方法

package com.example.demo;

import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.autoconfigure.domain.EntityScan;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.data.neo4j.repository.config.EnableNeo4jRepositories;
import org.springframework.transaction.annotation.EnableTransactionManagement;

//启动的时候扫描注解
@SpringBootApplication(scanBasePackages={"service","ctl","config","com.Utils"})//"com.shiro",
//扫描mybatis.xml 文件
@MapperScan({"com.shop.dao"})
//开启事务支持
@EnableTransactionManagement
@EntityScan("com.shop.Neo4jRepository.neoPojo")
@EnableNeo4jRepositories(basePackages = "com.shop.Neo4jRepository")
public class Main {

	public static void main(String[] args) {
		SpringApplication.run(Main.class, args);
	}

}```


@EntityScan("com.shop.Neo4jRepository.neoPojo") 去扫描有@NodeEntity注解的包才能生效

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