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。
this.charset = charset;
    }
    public Integer getPayload() {
        return payload;
    }
    public void setPayload(Integer payload) {
        this.payload = payload;
    }
    public Integer getBuffer() {
        return buffer;
    }
    public void setBuffer(Integer buffer) {
        this.buffer = buffer;
    }
    public Integer getHeartbeat() {
        return heartbeat;
    }
    public void setHeartbeat(Integer heartbeat) {
        this.heartbeat = heartbeat;
    }
    public String getServer() {
        return server;
    }
    public void setServer(String server) {
        this.server = server;
    }
    public String getClient() {
        return client;
    }
    public void setClient(String client) {