ThreadPoolExhaustedListener 在最新版本中未发现用户配置的入口，这个功能的设计初衷我理解，是发生线程池耗尽通知给应用，目前没看到应用如何添加监听的地方。
private Boolean register;
    /**
     * whether it is a persistent connection
     */
    
    private Boolean keepAlive;
    
    private String optimizer;
    /**
     * The extension
     */
    private String extension;
    /**
     * The customized parameters
     */
    private Map<String, String> parameters;
    private Boolean sslEnabled;
    /*
     * Extra Protocol for this service, using Port Unification Server
     */
    private String extProtocol;
    public ProtocolConfig() {
    }
    public ProtocolConfig(ApplicationModel applicationModel) {
        super(applicationModel);
    }
    public ProtocolConfig(String name) {
        setName(name);
    }
    public ProtocolConfig(ApplicationModel applicationModel, String name) {