class SocketBuilder {

    websocket: WebSocket;
  
    constructor(url: string) {
      if (typeof (WebSocket) === "undefined") {
        throw new Error('不支持websocket');
      }
      if (!url) {
        throw new Error('websocket url不能为空');
      }
      this.websocket = new WebSocket(url);
    }
  
    static builder(url: string) {
      return new SocketBuilder(url);
    }
  
    open(onopen: any) {
      this.websocket.onopen = onopen;
      return this;
    }
  
    error(onerror: any) {
      this.websocket.onerror = onerror;
      return this;
    }
  
    message(onmessage: any) {
      this.websocket.onmessage = onmessage;
      return this;
    }
  
    close(onclose: any) {
      this.websocket.onclose = onclose;
      return this;
    }
  
    build() {
      return this.websocket;
    }
  }

  
  export default SocketBuilder;