此 demo 主要演示了 Spring Boot 如何集成Neo4j操作图数据库，实现一个校园人物关系网。
作者编写本demo时，Neo4j 版本为 3.5.0，使用 docker 运行，下面是所有步骤：
- 下载镜像：
docker pull neo4j:3.5.0 - 运行容器：
docker run -d -p 7474:7474 -p 7687:7687 --name neo4j-3.5.0 neo4j:3.5.0 - 停止容器：
docker stop neo4j-3.5.0 - 启动容器：
docker start neo4j-3.5.0 - 浏览器 http://localhost:7474/ 访问 neo4j 管理后台，初始账号/密码 neo4j/neo4j，会要求修改初始化密码，我们修改为 neo4j/admin
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<artifactId>spring-boot-demo-neo4j</artifactId>
<version>1.0.0-SNAPSHOT</version>
<packaging>jar</packaging>
<name>spring-boot-demo-neo4j</name>
<description>Demo project for Spring Boot</description>
<parent>
<groupId>com.xkcoding</groupId>
<artifactId>spring-boot-demo</artifactId>
<version>1.0.0-SNAPSHOT</version>
</parent>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
<java.version>1.8</java.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-neo4j</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<optional>true</optional>
</dependency>
<dependency>
<groupId>cn.hutool</groupId>
<artifactId>hutool-all</artifactId>
</dependency>
<dependency>
<groupId>com.google.guava</groupId>
<artifactId>guava</artifactId>
</dependency>
</dependencies>
<build>
<finalName>spring-boot-demo-neo4j</finalName>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>spring:
data:
neo4j:
uri: bolt://localhost
username: neo4j
password: admin
open-in-view: false/**
* <p>
* 自定义主键策略
* </p>
*
* @author yangkai.shen
* @date Created in 2018-12-24 14:40
*/
public class CustomIdStrategy implements IdStrategy {
@Override
public Object generateId(Object o) {
return IdUtil.fastUUID();
}
}/**
* <p>
* 学生节点
* </p>
*
* @author yangkai.shen
* @date Created in 2018-12-24 14:38
*/
@Data
@NoArgsConstructor
@RequiredArgsConstructor(staticName = "of")
@AllArgsConstructor
@Builder
@NodeEntity
public class Student {
/**
* 主键，自定义主键策略，使用UUID生成
*/
@Id
@GeneratedValue(strategy = CustomIdStrategy.class)
private String id;
/**
* 学生姓名
*/
@NonNull
private String name;
/**
* 学生选的所有课程
*/
@Relationship(NeoConsts.R_LESSON_OF_STUDENT)
@NonNull
private List<Lesson> lessons;
/**
* 学生所在班级
*/
@Relationship(NeoConsts.R_STUDENT_OF_CLASS)
@NonNull
private Class clazz;
}/**
* <p>
* 学生节点Repository
* </p>
*
* @author yangkai.shen
* @date Created in 2018-12-24 15:05
*/
public interface StudentRepository extends Neo4jRepository<Student, String> {
/**
* 根据名称查找学生
*
* @param name 姓名
* @param depth 深度
* @return 学生信息
*/
Optional<Student> findByName(String name, @Depth int depth);
/**
* 根据班级查询班级人数
*
* @param className 班级名称
* @return 班级人数
*/
@Query("MATCH (s:Student)-[r:R_STUDENT_OF_CLASS]->(c:Class{name:{className}}) return count(s)")
Long countByClassName(@Param("className") String className);
/**
* 查询满足 (学生)-[选课关系]-(课程)-[选课关系]-(学生) 关系的 同学
*
* @return 返回同学关系
*/
@Query("match (s:Student)-[:R_LESSON_OF_STUDENT]->(l:Lesson)<-[:R_LESSON_OF_STUDENT]-(:Student) with l.name as lessonName,collect(distinct s) as students return lessonName,students")
List<ClassmateInfoGroupByLesson> findByClassmateGroupByLesson();
/**
* 查询师生关系，(学生)-[班级学生关系]-(班级)-[班主任关系]-(教师)
*
* @return 返回师生关系
*/
@Query("match (s:Student)-[:R_STUDENT_OF_CLASS]->(:Class)-[:R_BOSS_OF_CLASS]->(t:Teacher) with t.name as teacherName,collect(distinct s) as students return teacherName,students")
List<TeacherStudent> findTeacherStudentByClass();
/**
* 查询师生关系，(学生)-[选课关系]-(课程)-[任教老师关系]-(教师)
*
* @return 返回师生关系
*/
@Query("match ((s:Student)-[:R_LESSON_OF_STUDENT]->(:Lesson)-[:R_TEACHER_OF_LESSON]->(t:Teacher))with t.name as teacherName,collect(distinct s) as students return teacherName,students")
List<TeacherStudent> findTeacherStudentByLesson();
}/**
* <p>
* 测试Neo4j
* </p>
*
* @author yangkai.shen
* @date Created in 2018-12-24 15:17
*/
@Slf4j
public class Neo4jTest extends SpringBootDemoNeo4jApplicationTests {
@Autowired
private NeoService neoService;
/**
* 测试保存
*/
@Test
public void testSave() {
neoService.initData();
}
/**
* 测试删除
*/
@Test
public void testDelete() {
neoService.delete();
}
/**
* 测试查询 鸣人 学了哪些课程
*/
@Test
public void testFindLessonsByStudent() {
// 深度为1，则课程的任教老师的属性为null
// 深度为2，则会把课程的任教老师的属性赋值
List<Lesson> lessons = neoService.findLessonsFromStudent("漩涡鸣人", 2);
lessons.forEach(lesson -> log.info("【lesson】= {}", JSONUtil.toJsonStr(lesson)));
}
/**
* 测试查询班级人数
*/
@Test
public void testCountStudent() {
Long all = neoService.studentCount(null);
log.info("【全校人数】= {}", all);
Long seven = neoService.studentCount("第七班");
log.info("【第七班人数】= {}", seven);
}
/**
* 测试根据课程查询同学关系
*/
@Test
public void testFindClassmates() {
Map<String, List<Student>> classmates = neoService.findClassmatesGroupByLesson();
classmates.forEach((k, v) -> log.info("因为一起上了【{}】这门课，成为同学关系的有：{}", k, JSONUtil.toJsonStr(v.stream()
.map(Student::getName)
.collect(Collectors.toList()))));
}
/**
* 查询所有师生关系，包括班主任/学生，任课老师/学生
*/
@Test
public void testFindTeacherStudent() {
Map<String, Set<Student>> teacherStudent = neoService.findTeacherStudent();
teacherStudent.forEach((k, v) -> log.info("【{}】教的学生有 {}", k, JSONUtil.toJsonStr(v.stream()
.map(Student::getName)
.collect(Collectors.toList()))));
}
}运行测试类之后，可以通过访问 http://localhost:7474 ，查看neo里所有节点和关系
- spring-data-neo4j 官方文档：https://docs.spring.io/spring-data/neo4j/docs/5.1.2.RELEASE/reference/html/
- neo4j 官方文档：https://neo4j.com/docs/getting-started/3.5/