Servlet flushBuffer() Method Guide

In Servlet, you can use the response.flushBuffer() method to force the response content to be flushed to the client. Once flushBuffer() is called, the container will immediately send the response header and body to the client, and no further modifications can be made to the response.

The usage of the flushBuffer() method is as follows:

1. Response from the servlet
2. Please execute the doGet() method.
3. handle the post request

public void doGet(HttpServletRequest request, HttpServletResponse response)
    throws IOException, ServletException {
    // 获取ServletResponse对象
    HttpServletResponse httpServletResponse = (HttpServletResponse) response;
}

1. clearBuffer()

httpServletResponse.flushBuffer();

Please take note:

1. The flushBuffer() method must be called before the response is committed, otherwise it will throw an IllegalStateException exception.
2. If the response has already been committed before the flushBuffer() method is called, the flushBuffer() method will not take effect.
3. The flushBuffer() method is commonly used when there is a need to immediately send the response to the client, for example in certain special scenarios that require real-time responses.
4. In most cases, there is no need to explicitly call the flushBuffer() method because the container will automatically handle response flushing and committing.