@Deprecated public abstract class WebSocketServlet extends HttpServlet
|Constructor and Description|
|Modifier and Type||Method and Description|
Create the instance that will process this inbound connection.
Called by the server (via the
Intended to be overridden by sub-classes that wish to select a sub-protocol if the client provides a list of supported protocols.
Intended to be overridden by sub-classes that wish to verify the origin of a WebSocket request before processing it.
doDelete, doHead, doOptions, doPost, doPut, doTrace, getLastModified, service, service
destroy, getInitParameter, getInitParameterNames, getServletConfig, getServletContext, getServletInfo, getServletName, init, init, log, log
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException
servicemethod) to allow a servlet to handle a GET request.
Overriding this method to support a GET request also automatically supports an HTTP HEAD request. A HEAD request is a GET request that returns no body in the response, only the request header fields.
When overriding this method, read the request data,
write the response headers, get the response's writer or
output stream object, and finally, write the response data.
It's best to include content type and encoding. When using
PrintWriter object to return the response,
set the content type before accessing the
The servlet container must write the headers before committing the response, because in HTTP the headers must be sent before the response body.
Where possible, set the Content-Length header (with the
to allow the servlet container to use a persistent connection
to return its response to the client, improving performance.
The content length is automatically set if the entire response fits
inside the response buffer.
When using HTTP 1.1 chunked encoding (which means that the response has a Transfer-Encoding header), do not set the Content-Length header.
The GET method should be safe, that is, without any side effects for which users are held responsible. For example, most form queries have no side effects. If a client request is intended to change stored data, the request should use some other HTTP method.
The GET method should also be idempotent, meaning that it can be safely repeated. Sometimes making a method safe also makes it idempotent. For example, repeating queries is both safe and idempotent, but buying a product online or modifying data is neither safe nor idempotent.
If the request is incorrectly formatted,
returns an HTTP "Bad Request" message.
HttpServletRequestobject that contains the request the client has made of the servlet
HttpServletResponseobject that contains the response the servlet sends to the client
ServletException- if the request for the GET could not be handled
IOException- if an input or output error is detected when the servlet handles the GET request
protected boolean verifyOrigin(String origin)
origin- The value of the origin header from the request which may be
trueto accept the request.
falseto reject it. This default implementation always returns
subProtocols- The list of sub-protocols supported by the client in client preference order. The server is under no obligation to respect the declared preference
nullif no sub-protocol is selected or the name of the protocol which must be one of the protocols listed by the client. This default implementation always returns
protected abstract StreamInbound createWebSocketInbound(String subProtocol, HttpServletRequest request)
subProtocol- The sub-protocol agreed between the client and server or
nullif none was agreed
request- The HTTP request that initiated this WebSocket connection. Note that this object is only valid inside this method. You must not retain a reference to it outside the execution of this method. If Tomcat detects such access, it will throw an IllegalStateException
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