我的sockjs客户端在网页中,发送帧大小为16k的消息。消息大小限制是决定我可以传输文件的最大大小的最大大小。
以下是我在文档中发现的。
/**
* Configure the maximum size for an incoming sub-protocol message.
* For example a STOMP message may be received as multiple WebSocket messages
* or multiple HTTP POST requests when SockJS fallback options are in use.
*
* <p>In theory a WebSocket message can be almost unlimited in size.
* In practice WebSocket servers impose limits on incoming message size.
* STOMP clients for example tend to split large messages around 16K
* boundaries. Therefore a server must be able to buffer partial content
* and decode when enough data is received. Use this property to configure
* the max size of the buffer to use.
*
* <p>The default value is 64K (i.e. 64 * 1024).
*
* <p><strong>NOTE</strong> that the current version 1.2 of the STOMP spec
* does not specifically discuss how to send STOMP messages over WebSocket.
* Version 2 of the spec will but in the mean time existing client libraries
* have already established a practice that servers must handle.
*/
public WebSocketTransportRegistration setMessageSizeLimit(int messageSizeLimit) {
this.messageSizeLimit = messageSizeLimit;
return this;
}
我的问题:我可以设置部分消息传递,以便将文件部分传输,并且在现在完成时不会被传输为单个消息?
更新:仍在寻找通过部分消息传递的解决方案同时,现在使用http进行大消息(我的应用程序中的文件上传/下载)。
我可以设置部分消息传递,以便将文件部分传输到部分,并且在现在完成时不会被传输为单个消息?
是。这是我的Spring Boot实验项目中的相关配置 - 基本上是UploadWSHandler
已注册并设置了WebSocketTransportRegistration.setMessageSizeLimit
。
@Configuration
@EnableWebSocket
public class WebSocketConfig extends AbstractWebSocketMessageBrokerConfigurer implements WebSocketConfigurer {
public void registerWebSocketHandlers(WebSocketHandlerRegistry registry) {
registry.addHandler(new UploadWSHandler(), "/binary");
}
@Override
public void configureWebSocketTransport(WebSocketTransportRegistration registration) {
registration.setMessageSizeLimit(50 * 1024 * 1024);
}
}
uploadwshandler如下。对不起,这里的代码太多 - 要点
- 返回true的
supportsPartialMessage
-
handleBinaryMessage
将被多次调用,并带有部分消息,因此我们需要组装字节。因此,afterConnectionEstablished
使用WebSocket URL查询建立身份。但是您不必使用这种机制。之所以选择这种机制是要使客户端简单地使客户端简单,以便我只在javascript端将文件blob对象切成webSocket.send(files[0])
。(侧点:我想在客户端使用普通的Websocket -no Stomp/socks) - Iternal客户端块机制提供
message.isLast()
最后消息 - 出于演示目的,我将其写入文件系统并用
FileUploadInFlight
在内存中累积这些字节,但您不必这样做,并且可以在其他地方进行流式传输。
public class UploadWSHandler extends BinaryWebSocketHandler {
Map<WebSocketSession, FileUploadInFlight> sessionToFileMap = new WeakHashMap<>();
@Override
public boolean supportsPartialMessages() {
return true;
}
@Override
protected void handleBinaryMessage(WebSocketSession session, BinaryMessage message) throws Exception {
ByteBuffer payload = message.getPayload();
FileUploadInFlight inflightUpload = sessionToFileMap.get(session);
if (inflightUpload == null) {
throw new IllegalStateException("This is not expected");
}
inflightUpload.append(payload);
if (message.isLast()) {
Path basePath = Paths.get(".", "uploads", UUID.randomUUID().toString());
Files.createDirectories(basePath);
FileChannel channel = new FileOutputStream(
Paths.get(basePath.toString() ,inflightUpload.name).toFile(), false).getChannel();
channel.write(ByteBuffer.wrap(inflightUpload.bos.toByteArray()));
channel.close();
session.sendMessage(new TextMessage("UPLOAD "+inflightUpload.name));
session.close();
sessionToFileMap.remove(session);
}
String response = "Upload Chunk: size "+ payload.array().length;
System.out.println(response);
}
@Override
public void afterConnectionEstablished(WebSocketSession session) throws Exception {
sessionToFileMap.put(session, new FileUploadInFlight(session));
}
static class FileUploadInFlight {
String name;
String uniqueUploadId;
ByteArrayOutputStream bos = new ByteArrayOutputStream();
/**
* Fragile constructor - beware not prod ready
* @param session
*/
FileUploadInFlight(WebSocketSession session) {
String query = session.getUri().getQuery();
String uploadSessionIdBase64 = query.split("=")[1];
String uploadSessionId = new String(Base64Utils.decodeUrlSafe(uploadSessionIdBase64.getBytes()));
System.out.println(uploadSessionId);
List<String> sessionIdentifiers = Splitter.on("\").splitToList(uploadSessionId);
String uniqueUploadId = session.getRemoteAddress().toString()+sessionIdentifiers.get(0);
String fileName = sessionIdentifiers.get(1);
this.name = fileName;
this.uniqueUploadId = uniqueUploadId;
}
public void append(ByteBuffer byteBuffer) throws IOException{
bos.write(byteBuffer.array());
}
}
}
顺便说一句,一个工作项目也是sprint-boot-with-websocked-chunking-sembly-emembly and fetch in with-websocked-chunking-assembly-and-fetch
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