Filter processing garbled

@WebFilter("/*")
public class CharchaterFilter implements Filter {
    
    

    @Override
    public void init(FilterConfig filterConfig) throws ServletException {
    
    

    }

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
    
    
        //父接口转换为子接口
        HttpServletRequest request= (HttpServletRequest) servletRequest;
        HttpServletResponse response= (HttpServletResponse) servletResponse;
        //获取请求方法
        String method = request.getMethod();
        //如果是post方法就处理乱码问题
        if ("post".equalsIgnoreCase(method)){
    
    
            request.setCharacterEncoding("utf-8");
        }
        response.setContentType("text/html;charset=utf-8");
        //放行
        filterChain.doFilter(request,response);



    }

    @Override
    public void destroy() {
    
    

    }
}