Nebula Graph-06-NebulaGraph Java 使用 和SpringBoot集成Nebula Graph

前言

系列文章：
Nebula Graph-01-Nebula Graph简介和安装以及客户端连接
Nebula Graph-02-NebulaGraph高阶配置、用户管理、日志
Nebula Graph-03-NebulaGraph Studio-可视化web工具安装和使用
Nebula Graph-04-NebulaGraph nGQL的介绍和使用
Nebula Graph-05-NebulaGraph nGQL和SQL区别
Nebula Graph-06-NebulaGraph Java 使用 和SpringBoot集成Nebula Graph

---

Nebula Graph Java

NebulaGraph Java官网地址：https://docs.nebula-graph.com.cn/3.6.0/14.client/1.nebula-client/
官网说明及版本对比：https://github.com/vesoft-inc/nebula-java/tree/release-3.6

导包

如果使用 Maven 管理您的项目，请将以下依赖项添加到您的文件中。 替换为适当的 Nebula Java 版本。

<dependency>
    <groupId>com.vesoft</groupId>
    <artifactId>client</artifactId>
    <version>3.0-SNAPSHOT</version>
</dependency>

客户端版本和Nebula Graph 版本对应

连接

Java调用主要是三部分, 创建连接池, 创建会话, 执行查询

创建 NebulaPool 连接池

NebulaPool pool = new NebulaPool();
try {
	NebulaPoolConfig nebulaPoolConfig = new NebulaPoolConfig();
	nebulaPoolConfig.setMaxConnSize(100);
	List<HostAddress> addresses = Arrays.asList(new HostAddress("127.0.0.1", 9669));
	Boolean initResult = pool.init(addresses, nebulaPoolConfig);
	if (!initResult) {
		log.error("pool init failed.");
		return;
	}
} catch ()
//...

创建 Session 会话

Session session = pool.getSession("root", "nebula", false);

执行查询

创建一个SPACE, 然后使用这个SPACE, 创建一个TAG person, 创建一个EDGE like

String createSchema = "CREATE SPACE IF NOT EXISTS test(vid_type=fixed_string(20)); "
		+ "USE test;"
		+ "CREATE TAG IF NOT EXISTS person(name string, age int);"
		+ "CREATE EDGE IF NOT EXISTS like(likeness double)";
ResultSet resp = session.execute(createSchema);
if (!resp.isSucceeded()) {
	log.error(String.format("Execute: `%s', failed: %s",
			createSchema, resp.getErrorMessage()));
	System.exit(1);
}

简单使用-helloWorld

package com.example.demo;

import com.vesoft.nebula.client.graph.NebulaPoolConfig;
import com.vesoft.nebula.client.graph.data.HostAddress;
import com.vesoft.nebula.client.graph.data.ResultSet;
import com.vesoft.nebula.client.graph.net.NebulaPool;
import com.vesoft.nebula.client.graph.net.Session;


import java.util.Arrays;
import java.util.List;

/**
 * @author wangkanglu
 * @version 1.0
 * @description
 * @date 2024-03-25 14:10
 */
public class TestNebulaGraph {


    public static void main(String[] args) {
        try {
            NebulaPoolConfig nebulaPoolConfig=new NebulaPoolConfig();
            nebulaPoolConfig.setMaxConnSize(10);
            List<HostAddress> addresses= Arrays.asList(new HostAddress("192.168.217.129",9669));
            NebulaPool pool=new NebulaPool();
            Boolean initResult = pool.init(addresses,nebulaPoolConfig);
            //创建 Session 会话,创建会话时需要用户名和密码
            //参数：账号/密码/是否断开后重试
            Session session=pool.getSession("root","nebula",false);
            ResultSet resultSet = session.execute("SHOW HOSTS;");
            //通知服务器不再需要该会话，并将连接返回到池，该连接将被重用。如果用户不再使用会话，则调用此函数。
            session.release();
            pool.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

NebulaGraph Java Client API

地址：https://vesoft-inc.github.io/nebula-java/release-3.6/annotated.html

在 SpringBoot 项目中使用 Nebula Graph

导包

<dependency>
    <groupId>com.vesoft</groupId>
    <artifactId>client</artifactId>
    <version>3.0.0</version>
</dependency>
<dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>fastjson</artifactId>
    <version>1.2.83</version>
</dependency>

配合FastJson一起用比较方便, 为了解决fastjson漏洞问题, 使用1.2.83及其以上版本

配置文件

nebula:
  address[0]:
    host: 192.168.247.130
    port: 9669
  username: root
  password: 123456
  reconnect: false
  space: my_space

• address[0]: 因为是开发, 所以配置为单机的, 等部署生产的话, 可以增加address[1-…]来完成集群的配置
• space: 图空间

配置连接

1：声明 NebulaProperties 接收上面的配置信息：

package com.example.demo.nebula;

import lombok.Data;

@Data
public class NebulaAddress {
    private String host;
    private Integer port;
}

package com.example.demo.nebula;

import lombok.Data;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.context.annotation.Configuration;

import java.util.List;
 
@Data
@Configuration
@ConfigurationProperties(prefix = "nebula")
public class NebulaProperties {
    private List<NebulaAddress> address;
    private String username;
    private String password;
    private boolean reconnect;
    private String space;
}

2：声明 NebulaConfig ，初始化 NebulaPool ，及声明 Session 的获取方式：

package com.example.demo.nebula;

import com.sun.javafx.binding.StringFormatter;
import com.vesoft.nebula.client.graph.NebulaPoolConfig;
import com.vesoft.nebula.client.graph.data.HostAddress;
import com.vesoft.nebula.client.graph.net.NebulaPool;
import com.vesoft.nebula.client.graph.net.Session;
import lombok.extern.slf4j.Slf4j;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Scope;
import org.springframework.context.annotation.ScopedProxyMode;

import java.util.stream.Collectors;

/**
 * @author wangkanglu
 * @version 1.0
 * @description
 * @date 2024-03-25 15:35
 */
@Slf4j
@Configuration
public class NebulaConfig {

    @Bean
    public NebulaPool nebulaPool(NebulaProperties nebulaProperties) throws Exception {
        NebulaPool pool = new NebulaPool();
        NebulaPoolConfig nebulaPoolConfig = new NebulaPoolConfig();
        nebulaPoolConfig.setMaxConnSize(1000);
        boolean init = pool.init(nebulaProperties.getAddress().stream().map(d -> new HostAddress(d.getHost(), d.getPort())).collect(Collectors.toList()), nebulaPoolConfig);
        if (!init){
            throw new RuntimeException("NebulaGraph init err !");
        }else {
            log.info("NebulaGraph init Success ！");
        }
        return pool;
    }

    @Bean
    @Scope(scopeName = "prototype",proxyMode = ScopedProxyMode.TARGET_CLASS)
    public Session session(NebulaPool nebulaPool, NebulaProperties nebulaProperties) {
        try {
            Session session = nebulaPool.getSession(nebulaProperties.getUsername(), nebulaProperties.getPassword(), nebulaProperties.isReconnect());
            session.execute(StringFormatter.concat(NebulaConstant.USE, nebulaProperties.getSpace(), NebulaConstant.SEMICOLON).getValue());
            return session;
        } catch (Exception e) {
            log.error("get nebula session err , {} ", e.toString());
        }
        return null;
    }

}

定义Nebula 常量和返回结果

1:定义常量

package com.example.demo.nebula;

import lombok.AllArgsConstructor;
import lombok.Getter;

/**
 * @author wangkanglu
 * @version 1.0
 * @description
 * @date 2024-03-25 15:36
 */
public class NebulaConstant {

    public static final String USE = "USE ";
    public static final String SEMICOLON = "; ";
    public static final String ERROR_CODE = "-1";

    @Getter
    @AllArgsConstructor
    public enum NebulaJson{
        ERRORS("errors"),
        CODE("code"),
        MESSAGE("message"),
        RESULTS("results"),
        COLUMNS("columns"),
        DATA("data"),
        ROW("row");
        private String key;
    }
}

2：为了方便对结果的解析，再声明一个 NebulaResult 用来接收结果

package com.example.demo.nebula;

import lombok.Data;

import java.util.List;

/**
 * @author wangkanglu
 * @version 1.0
 * @description
 * @date 2024-03-25 15:37
 */
@Data
public class NebulaResult<T>{
    private Integer code;
    private String message;
    private List<T> data;

    public boolean isSuccessed(){
        return code == 0;
    }
}

封装一个 NebulaTemplate

package com.example.demo.nebula;

import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONArray;
import com.alibaba.fastjson.JSONObject;
import com.vesoft.nebula.client.graph.net.Session;
import lombok.extern.slf4j.Slf4j;
import org.springframework.stereotype.Component;

import javax.annotation.Resource;
import java.util.ArrayList;
import java.util.List;
import java.util.Objects;
import java.util.Optional;
import java.util.stream.Collectors;

/**
 * @author wangkanglu
 * @version 1.0
 * @description
 * @date 2024-03-25 15:37
 */
@Slf4j
@Component
public class NebulaTemplate {

    @Resource
    Session session;

    public <T> NebulaResult<T> queryObject(String stmt, Class<T> tClass) {
        NebulaResult<T> nebulaResult = executeObject(stmt);
        if (Objects.isNull(nebulaResult.getData())) {
            return nebulaResult;
        }
        Optional.ofNullable(nebulaResult.getData()).ifPresent(data -> nebulaResult.setData(data.stream().map(d -> JSONObject.toJavaObject(((JSONObject) d), tClass)).collect(Collectors.toList())));
        return nebulaResult;
    }

    public NebulaResult executeObject(String stmt) {
        JSONObject jsonObject = executeJson(stmt);
        return JSONObject.toJavaObject(jsonObject, NebulaResult.class);
    }

    public JSONObject executeJson(String stmt) {
        JSONObject restJson = new JSONObject();
        try {
            JSONObject jsonObject = JSON.parseObject(Objects.requireNonNull(session).executeJson(stmt));
            JSONObject errors = jsonObject.getJSONArray(NebulaConstant.NebulaJson.ERRORS.getKey()).getJSONObject(0);
            restJson.put(NebulaConstant.NebulaJson.CODE.getKey(), errors.getInteger(NebulaConstant.NebulaJson.CODE.getKey()));
            if (errors.getInteger(NebulaConstant.NebulaJson.CODE.getKey()) != 0) {
                restJson.put(NebulaConstant.NebulaJson.MESSAGE.getKey(), errors.getString(NebulaConstant.NebulaJson.MESSAGE.getKey()));
                return restJson;
            }
            JSONObject results = jsonObject.getJSONArray(NebulaConstant.NebulaJson.RESULTS.getKey()).getJSONObject(0);
            JSONArray columns = results.getJSONArray(NebulaConstant.NebulaJson.COLUMNS.getKey());
            if (Objects.isNull(columns)) {
                return restJson;
            }
            JSONArray data = results.getJSONArray(NebulaConstant.NebulaJson.DATA.getKey());
            if (Objects.isNull(data)) {
                return restJson;
            }
            List<JSONObject> resultList = new ArrayList<>();
            data.stream().map(d -> (JSONObject) d).forEach(d -> {
                JSONArray row = d.getJSONArray(NebulaConstant.NebulaJson.ROW.getKey());
                JSONObject map = new JSONObject();
                for (int i = 0; i < columns.size(); i++) {
                    map.put(columns.getString(i), row.get(i));
                }
                resultList.add(map);
            });
            restJson.put(NebulaConstant.NebulaJson.DATA.getKey(), resultList);
        } catch (Exception e) {
            restJson.put(NebulaConstant.NebulaJson.CODE.getKey(), NebulaConstant.ERROR_CODE);
            restJson.put(NebulaConstant.NebulaJson.MESSAGE.getKey(), e.toString());
            log.error("nebula execute err：", e);
        }
        return restJson;
    }

}

测试

 package com.example.demo;

import com.example.demo.nebula.NebulaResult;
import com.example.demo.nebula.NebulaTemplate;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;

@SpringBootTest
class DemoApplicationTests {

    @Autowired
    NebulaTemplate nebulaTemplate;


    @Test
    public void test1(){
        String sql = "SHOW HOSTS;";
        NebulaResult nebulaResult = nebulaTemplate.executeObject(sql);
        System.out.println(nebulaResult);
    }


}