java 操作neo4j代码

以下是使用Java操作Neo4j数据库的示例代码：

1. 首先，需要引入Neo4j的Java驱动程序，例如：

<dependency>
    <groupId>org.neo4j.driver</groupId>
    <artifactId>neo4j-java-driver</artifactId>
    <version>1.7.5</version>
</dependency>

2. 然后，连接到Neo4j数据库：

import org.neo4j.driver.v1.*;

public class Neo4jExample {
    public static void main(String[] args) {
        // 连接到Neo4j数据库
        Driver driver = GraphDatabase.driver("bolt://localhost:7687", AuthTokens.basic("neo4j", "password"));
        
        // 执行Cypher查询
        try (Session session = driver.session()) {
            String query = "MATCH (n) RETURN count(n) as count";
            StatementResult result = session.run(query);
            
            // 处理查询结果
            while (result.hasNext()) {
                Record record = result.next();
                long count = record.get("count").asLong();
                System.out.println("Node count: " + count);
            }
        }
        
        // 关闭连接
        driver.close();
    }
}

3. 可以执行各种Cypher查询和更新操作，例如：

// 创建节点
String query = "CREATE (p:Person {name: 'Alice'}) RETURN p";
StatementResult result = session.run(query);
Record record = result.single();
Node node = record.get("p").asNode();

// 更新节点属性
String query = "MATCH (p:Person {name: 'Alice'}) SET p.age = 30";
session.run(query);

// 查询节点和关系
String query = "MATCH (p:Person)-[r:FRIEND]->(q:Person) WHERE p.name = 'Alice' RETURN r, q";
StatementResult result = session.run(query);
while (result.hasNext()) {
    Record record = result.next();
    Relationship relationship = record.get("r").asRelationship();
    Node node = record.get("q").asNode();
    // 处理查询结果
}

// 删除节点和关系
String query = "MATCH (p:Person)-[r:FRIEND]->() WHERE p.name = 'Alice' DELETE r, p";
session.run(query);

以上代码仅供参考，实际操作中需要根据具体需求进行修改和优化。