如何在spring filter中获取请求体参数？

import javax.servlet.*;
import javax.servlet.http.HttpServletRequest;
import java.io.IOException;

public class CustomFilter implements Filter {
    @Override
    public void init(FilterConfig filterConfig) throws ServletException {
        // 初始化操作
    }

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        HttpServletRequest request = (HttpServletRequest) servletRequest;

        // 获取请求参数
        String param1 = request.getParameter("param1");
        String param2 = request.getParameter("param2");

        // 处理请求参数
        // ...

        // 调用下一个过滤器或目标资源
        filterChain.doFilter(servletRequest, servletResponse);
    }

    @Override
    public void destroy() {
        // 销毁操作
    }
}