SpringBoot中如何使用RequestContextHolder.getRequestAttributes()).getRequest()来获取请求参数，并且解决并发问题

在SpringBoot中，可以使用RequestContextHolder.getRequestAttributes()).getRequest()来获取请求参数。具体实现方式如下：

1. 在Controller中定义一个方法，用于获取请求参数。

public String getRequestParam() {
    HttpServletRequest request = ((ServletRequestAttributes) RequestContextHolder.getRequestAttributes()).getRequest();
    String param = request.getParameter("param");
    //处理业务逻辑
    return "success";
}

2. 在多线程环境中，由于RequestContextHolder是线程绑定的，可能会出现并发问题。为了解决这个问题，可以使用ThreadLocal来保存请求信息。

public class RequestContextHolder {
    private static ThreadLocal<HttpServletRequest> requestHolder = new ThreadLocal<>();

    public static void set(HttpServletRequest request) {
        requestHolder.set(request);
    }

    public static HttpServletRequest get() {
        return requestHolder.get();
    }

    public static void remove() {
        requestHolder.remove();
    }
}

在Filter中设置请求信息到ThreadLocal中：

public class RequestFilter implements Filter {
    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        HttpServletRequest request = (HttpServletRequest) servletRequest;
        RequestContextHolder.set(request);
        filterChain.doFilter(servletRequest, servletResponse);
        RequestContextHolder.remove();
    }
}

然后在Controller中通过RequestContextHolder.get()获取请求信息。

public String getRequestParam() {
    HttpServletRequest request = RequestContextHolder.get();
    String param = request.getParameter("param");
    //处理业务逻辑
    return "success";
}

这样就可以解决并发问题了。