如何在 HandshakeInterceptor 中设置主体

我正在使用 Spring 的 WebSockets 的一个非常精简的实现。 WebSocketSession 有 getPrincipal() 方法，但如何在 HandshakeInterceptor 中设置它？

我想将校长放入的方法是：

public boolean beforeHandshake(final ServerHttpRequest request, final ServerHttpResponse response, final WebSocketHandler wsHandler,
        final Map<String, Object> attributes) throws Exception {
    Principal = getPrincipal();
    // Now where to set the principal so it is available in WebSocketSession?

}

registry.addEndpoint("/hello") 
.setHandshakeHandler(new DefaultHandshakeHandler() {
     @Override
     protected Principal determineUser(ServerHttpRequest request, WebSocketHandler wsHandler, Map<String, Object> attributes) {

 //Here you can set and return principal that is used by websocket session.            
}