Firebase使用Swift 3.0返回Optional（）(Firebase returning Optional() with Swift 3.0)

 在你的连接方法中，你可以离开 
 
 不要使用相同的端点“hello”和MessageMapping，会混淆 
 
public void registerStompEndpoints(StompEndpointRegistry registry) {
    registry.addEndpoint("/ws")
        .setAllowedOrigins("*").withSockJS();
}

var socket = new SockJS('/hello');
 
 这里还删除了contextPath vix 
 
stompClient.subscribe('/topic/greetings', function(greeting){
    showGreeting(JSON.parse(greeting.body).content);
});
 
 这里再次相同 
 
 stompClient.send("/app/hello", {}, JSON.stringify({ 'name': name }));
 
 基本上，所有问题都是添加上下文，因为在添加第一个“/”时默认添加上下文 

In your connect method you can just leave
 
Don't use the same endpoint "hello" and MessageMapping, will be confuse 
 
public void registerStompEndpoints(StompEndpointRegistry registry) {
    registry.addEndpoint("/ws")
        .setAllowedOrigins("*").withSockJS();
}

var socket = new SockJS('/hello');
 
Here also remove the contextPath vix
 
stompClient.subscribe('/topic/greetings', function(greeting){
    showGreeting(JSON.parse(greeting.body).content);
});
 
Here again the same
 
 stompClient.send("/app/hello", {}, JSON.stringify({ 'name': name }));
 
Basically, all problem was adding the context because the context was added by default when you add the first "/"