tomcat中有提到：

If the application does not define a MessageHandler.Partial for incoming text messages, any incoming text messages must be buffered so the entire message can be delivered in a single call to the registered MessageHandler.
Whole for text messages. The default buffer size for text messages is 8192 bytes. This may be changed for a web application by setting the servlet context initialization parameter org.apache.tomcat.websocket.
 
textBufferSize to the desired value in bytes.

1、對專案web.xml新增如下配置（注意單位為byte）

<context-param>
    <param-name>org.apache.tomcat.websocket.textBufferSize</param-name>
    <param-value>5242800</param-value>
</context-param>

2、對於spring工程來說這個方法沒問題可以生效，但是springboot並沒有web.xml該如何解決呢？如下：

@Configuration
@ComponentScan
@EnableAutoConfiguration
public class WebSocketConfig implements ServletContextInitializer{
    
    //配置websocket傳輸大小，50M
    @Override
    public void onStartup(ServletContext servletContext) throws ServletException {
        servletContext.addListener(WebAppRootListener.
 
class);
        servletContext.setInitParameter("org.apache.tomcat.websocket.textBufferSize","52428800");
        servletContext.setInitParameter("org.apache.tomcat.websocket.binaryBufferSize","52428800");
    }
}

注意：在使用的時候還發現了一個問題，如上配置假如是以springboot內建tomcat啟動是沒有問題的，但是打成war後使用外接tomcat執行卻不生效，最終發現是因為外接tomcat版本問題，出問題的版本是tomcat8.0.xx，而使用tomcat8.5.xx就沒有這個問題了

參考連結：https://blog.csdn.net/luohualiushui1/article/details/86596754