[JAVA版本] Websocket获取B站直播弹幕——基于直播开放平台

教程

B站直播间弹幕Websocket获取 — 哔哩哔哩直播开放平台
基于B站直播开放平台开放且未上架时，只能个人使用。

代码实现

1、相关依赖

fastjson2用于解析JSON字符串，可自行替换成别的框架。
hutool-core用于解压zip数据，可自行替换成别的框架。

<dependency><groupId>com.alibaba.fastjson2</groupId><artifactId>fastjson2</artifactId><version>2.0.40</version>
</dependency>
<!-- https://mvnrepository.com/artifact/cn.hutool/hutool-core -->
<dependency><groupId>cn.hutool</groupId><artifactId>hutool-core</artifactId><version>5.8.21</version>
</dependency>

1、新建ProjectRequest.java

用于发送项目start、end、heartbeat请求。
注意：
没有上架的项目，start返回结果没有场次ID，导致end、heartbeat请求不能正常执行。
但是没有关系，start能获得弹幕服务信息就行。

import com.alibaba.fastjson2.JSONArray;
import com.alibaba.fastjson2.JSONObject;
import jakarta.annotation.Nonnull;
import javax.crypto.Mac;
import javax.crypto.spec.SecretKeySpec;
import java.io.BufferedReader;
import java.io.DataOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.nio.charset.StandardCharsets;
import java.security.InvalidKeyException;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.UUID;
import java.util.stream.Collectors;public class ProjectRequest {/*** 项目ID*/private long appId;/*** 身份验证Key*/private String accessKey;/*** 身份验证密钥*/private String accessSecret;public ProjectRequest(long appId, String accessKey, String accessSecret) {this.appId = appId;this.accessKey = accessKey;this.accessSecret = accessSecret;}public final static String START_URL = "https://live-open.biliapi.com/v2/app/start";public final static String END_URL = "https://live-open.biliapi.com/v2/app/end";public final static String HEART_BEAT_URL = "https://live-open.biliapi.com/v2/app/heartbeat";public final static String BATCH_HEART_BEAT_URL = "https://live-open.biliapi.com/v2/app/batchHeartbeat";/*** 接口描述：开启项目第一步，平台会根据入参进行鉴权校验。鉴权通过后，返回长连信息、场次信息和主播信息。开发者拿到长连和心跳信息后，需要参照[长连说明]和[项目心跳]，与平台保持健康的* @param code 必填	string	[主播身份码]* param appId 必填	integer(13位长度的数值，注意不要用普通int，会溢出的)	项目ID*/public String start(String code) throws IOException, NoSuchAlgorithmException, InvalidKeyException {Map<String,Object> params = new HashMap<>();params.put("code", code);params.put("app_id", appId);return post(START_URL, params);}/*** 接口描述：项目关闭时需要主动调用此接口，使用对应项目Id及项目开启时返回的game_id作为唯一标识，调用后会同步下线互动道具等内容，项目关闭后才能进行下一场次互动。* param appId 必填	integer(13位长度的数值，注意不要用普通int，会溢出的)	项目ID* param gameId 必填	场次id*/public String end(String gameId) throws IOException, NoSuchAlgorithmException, InvalidKeyException {Map<String,Object> params = new HashMap<>();params.put("game_id", gameId);params.put("app_id", appId);return post(END_URL, params);}/*** 接口描述：项目开启后，需要持续间隔20秒调用一次该接口。平台超过60s未收到项目心跳，会自动关闭当前场次（game_id），同时将道具相关功能下线，以确保下一场次项目正常运行。* 接口地址：/v2/app/heartbeat* 方法：POST* param gameId 必填	场次id*/public String heartbeat(String gameId) throws IOException, NoSuchAlgorithmException, InvalidKeyException {Map<String,Object> params = new HashMap<>();params.put("game_id", gameId);return post(HEART_BEAT_URL, params);}/*** 项目批量心跳* 接口地址：/v2/app/batchHeartbeat* 方法：POST* @param gameIds    必填	[]string	场次id* */public String batchHeartbeat(@Nonnull List<String> gameIds) throws IOException, NoSuchAlgorithmException, InvalidKeyException {Map<String,Object> params = new HashMap<>();params.put("game_ids", JSONArray.toJSONString(gameIds));return post(HEART_BEAT_URL, params);}/*** 自定义post请求* @param url* @param dataMap* @throws IOException* @throws NoSuchAlgorithmException* @throws InvalidKeyException*/private String post(String url, Map<String,Object> dataMap) throws IOException, NoSuchAlgorithmException, InvalidKeyException {String bodyStr = JSONObject.toJSONString(dataMap);HttpURLConnection con = (HttpURLConnection) new URL(url).openConnection();con.setRequestMethod("POST");// 设置请求头setHeader(con, bodyStr);// 发送 POST 请求con.setDoOutput(true);try(DataOutputStream wr = new DataOutputStream(con.getOutputStream())) {wr.writeBytes(bodyStr);wr.flush();}// 获取响应结果try(BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(con.getInputStream(), StandardCharsets.UTF_8))){// 返回响应结果return  bufferedReader.lines().collect(Collectors.joining("\n"));}}public static String KEY_CONTENT_MD5 = "x-bili-content-md5";public static String KEY_TIMESTAMP = "x-bili-timestamp";public static String KEY_SIGNATURE_NONCE = "x-bili-signature-nonce";/*** 设置请求头* @param con* @param bodyStr 请求体* @throws NoSuchAlgorithmException* @throws InvalidKeyException*/private void setHeader(HttpURLConnection con,String bodyStr) throws NoSuchAlgorithmException, InvalidKeyException {con.setRequestProperty("User-Agent", "Mozilla/5.0");/**----------------------------------------------------------------------------**///必填：接受的返回结果的类型。目前只支持JSON类型，取值：application/json。con.setRequestProperty("Accept", "application/json");//必填：当前请求体（Request Body）的数据类型。目前只支持JSON类型，取值：application/json。con.setRequestProperty("Content-Type", "application/json");//必填：请求体的编码值，根据请求体计算所得。算法说明：将请求体内容当作字符串进行MD5编码。con.setRequestProperty(KEY_CONTENT_MD5, getContentMd5(bodyStr));//必填：unix时间戳，单位是秒。请求时间戳不能超过当前时间10分钟，否则请求会被丢弃。con.setRequestProperty(KEY_TIMESTAMP, String.valueOf(System.currentTimeMillis()/1000));//必填： 版本1.0con.setRequestProperty("x-bili-signature-version", "1.0");//必填：签名唯一随机数。用于防止网络重放攻击，建议您每一次请求都使用不同的随机数con.setRequestProperty(KEY_SIGNATURE_NONCE, UUID.randomUUID().toString());//必填：加密算法con.setRequestProperty("x-bili-signature-method", "HMAC-SHA256");//必填： accesskey idcon.setRequestProperty("x-bili-accesskeyid", accessKey);//必填：请求签名（注意生成的签名是小写的）。关于请求签名的计算方法，请参见签名机制con.setRequestProperty("Authorization", generateSignature(con));}/*** MD5计算*/private String getContentMd5(String content) throws NoSuchAlgorithmException {MessageDigest md5 = MessageDigest.getInstance("MD5");return byte2Hex( md5.digest(content.getBytes(StandardCharsets.UTF_8)) );}/*** 签名 HmacSHA256计算*/public String generateSignature(HttpURLConnection con) throws NoSuchAlgorithmException, InvalidKeyException {StringBuilder s = new StringBuilder();s.append("x-bili-accesskeyid:").append(accessKey).append("\n");s.append("x-bili-content-md5:").append(con.getRequestProperty(KEY_CONTENT_MD5)).append("\n");s.append("x-bili-signature-method:").append("HMAC-SHA256").append("\n");s.append("x-bili-signature-nonce:").append(con.getRequestProperty(KEY_SIGNATURE_NONCE)).append("\n");s.append("x-bili-signature-version:").append("1.0").append("\n");s.append("x-bili-timestamp:").append(con.getRequestProperty(KEY_TIMESTAMP));byte[] headerByte = s.toString().getBytes(StandardCharsets.UTF_8);byte[] secretByte = accessSecret.getBytes(StandardCharsets.UTF_8);Mac mac = Mac.getInstance("HmacSHA256");mac.init(new SecretKeySpec(secretByte, "HmacSHA256"));byte[] bytes = mac.doFinal(headerByte);return byte2Hex(bytes);}/*** 字节数组转16进制字符串* @param bytes* @return*/private static String byte2Hex(byte[] bytes){StringBuffer stringBuffer = new StringBuffer();String temp = null;for (int i=0;i<bytes.length;i++){temp = Integer.toHexString(bytes[i] & 0xFF);if (temp.length()==1){//1得到一位的进行补0操作stringBuffer.append("0");}stringBuffer.append(temp);}return stringBuffer.toString();}
}

3、新建 WebsocketListener.java

用于监听接收到的数据。

import jakarta.websocket.*;
import java.io.ByteArrayOutputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.nio.ByteBuffer;
import java.nio.charset.StandardCharsets;
import java.util.concurrent.Executors;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.TimeUnit;
import cn.hutool.core.util.ZipUtil;@ClientEndpoint
public class WebsocketListener {private Session session;private String authBody;public WebsocketListener(String authBody) {this.authBody = authBody;}@OnOpenpublic void onOpen(Session session) throws IOException {System.out.println("已连接服务...");this.session = session;RemoteEndpoint.Async remote = session.getAsyncRemote();//鉴权协议包ByteBuffer authPack = ByteBuffer.wrap(generateAuthPack(authBody));remote.sendBinary(authPack);//每30秒发送心跳包ScheduledExecutorService executorService = Executors.newSingleThreadScheduledExecutor();executorService.scheduleAtFixedRate(() -> {try {ByteBuffer heartBeatPack = ByteBuffer.wrap(generateHeartBeatPack());remote.sendBinary(heartBeatPack);} catch (IOException e) {throw new RuntimeException(e);}}, 0, 30, TimeUnit.SECONDS);}@OnMessagepublic void onMessage(ByteBuffer byteBuffer) {//解包unpack(byteBuffer);}@OnClosepublic void onClose(Session session, CloseReason closeReason) {System.out.println("关闭Websocket服务: " + closeReason);}@OnErrorpublic void onError(Session session, Throwable t) {System.out.println("Websocket服务异常: " + t.getMessage());}public interface Opt{short HEARTBEAT = 2;//	客户端发送的心跳包(30秒发送一次)short HEARTBEAT_REPLY = 3;//	服务器收到心跳包的回复 人气值，数据不是JSON，是4字节整数short SEND_SMS_REPLY = 5;//	服务器推送的弹幕消息包short AUTH = 7;//客户端发送的鉴权包(客户端发送的第一个包)short AUTH_REPLY = 8;//服务器收到鉴权包后的回复}public interface Version{short NORMAL = 0;//Body实际发送的数据——普通JSON数据short ZIP = 2; //Body中是经过压缩后的数据，请使用zlib解压，然后按照Proto协议去解析。}/*** 封包* @param jsonStr 数据* @param code 协议包类型* @return* @throws IOException*/public static byte[] pack(String jsonStr, short code) throws IOException {byte[] contentBytes = new byte[0];if(Opt.AUTH == code){contentBytes = jsonStr.getBytes();}try(ByteArrayOutputStream data = new ByteArrayOutputStream();DataOutputStream stream = new DataOutputStream(data)){stream.writeInt(contentBytes.length + 16);//封包总大小stream.writeShort(16);//头部长度 header的长度，固定为16stream.writeShort(Version.NORMAL);stream.writeInt(code);//操作码（封包类型）stream.writeInt(1);//保留字段，可以忽略。if(Opt.AUTH == code){stream.writeBytes(jsonStr);}return data.toByteArray();}}/*** 生成认证包* @return*/public static byte[] generateAuthPack(String jsonStr) throws IOException {return pack(jsonStr, Opt.AUTH);}/*** 生成心跳包* @return*/public static byte[] generateHeartBeatPack() throws IOException {return pack(null, Opt.HEARTBEAT);}/*** 解包* @param byteBuffer* @return*/public static void unpack(ByteBuffer byteBuffer){int packageLen = byteBuffer.getInt();short headLength = byteBuffer.getShort();short protVer = byteBuffer.getShort();int optCode = byteBuffer.getInt();int sequence = byteBuffer.getInt();if(Opt.HEARTBEAT_REPLY == optCode){System.out.println("这是服务器心跳回复");}byte[] contentBytes = new byte[packageLen - headLength];byteBuffer.get(contentBytes);//如果是zip包就进行解包if(Version.ZIP == protVer){unpack(ByteBuffer.wrap(ZipUtil.unZlib(contentBytes)));return;}String content = new String(contentBytes, StandardCharsets.UTF_8);if(Opt.AUTH_REPLY == optCode){//返回{"code":0}表示成功System.out.println("这是鉴权回复："+content);}//真正的弹幕消息if(Opt.SEND_SMS_REPLY == optCode){System.out.println("真正的弹幕消息："+content);// todo 自定义处理}//只存在ZIP包解压时才有的情况//如果byteBuffer游标 小于 byteBuffer大小，那就证明还有数据if(byteBuffer.position() < byteBuffer.limit()){unpack(byteBuffer);}}
}

4、使用

public static void main(String[] args) throws IOException, NoSuchAlgorithmException, InvalidKeyException, URISyntaxException, DeploymentException {ProjectRequest p = new ProjectRequest(你的应用ID, 你的Access_key, 你的 Access_Secret);//获取弹幕服务信息String result = p.start(你的身份码);JSONObject data = JSONObject.parseObject(result).getJSONObject("data");//个人信息JSONObject anchorInfo = data.getJSONObject("anchor_info");//弹幕服务器信息JSONObject websocketInfo = data.getJSONObject("websocket_info");//弹幕服务器地址JSONArray wssLinks = websocketInfo.getJSONArray("wss_link");//websocket鉴权信息String authBody = websocketInfo.getString("auth_body");//选一个服务器节点String uri = wssLinks.getString(0);WebSocketContainer container = ContainerProvider.getWebSocketContainer();// 连接到WebSocket服务器container.connectToServer(new WebsocketListener(authBody), new URI(uri)); 
}

参数获取
Access_key 和 Access_Secret	去B站直播开放平台注册申请个人开发者后就能获得
应用ID	成为个人开发者后，在直播开放平台创建应用后，就能获得应用ID
身份码	登录B站直播间找到幻星-互动玩法，在里面就能找到身份码

其他版本

【flutter / dart 版本】Websocket获取B站直播间弹幕教程——基于B站直播开发平台