JAVA解决跨域,OPTIONS请求问题,跨域时ajax发送两次请求,文件上传等跨域问题

package com.zz.tiger.config;

import java.io.IOException;

import jakarta.servlet.*;
import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletResponse;
import org.springframework.core.Ordered;
import org.springframework.core.annotation.Order;
import org.springframework.stereotype.Component;
 
@Component
//Spring将使用这些提供的顺序值对组件进行排序,让他处于最前面执行
@Order(Ordered.HIGHEST_PRECEDENCE)
public class ConfigCtrl implements Filter {
    @Override
    public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain) throws IOException, ServletException {
        final HttpServletResponse response = (HttpServletResponse) res;
        response.setHeader("Access-Control-Allow-Origin", "*");
        response.setHeader("Access-Control-Allow-Methods", "POST, PUT, GET, OPTIONS, DELETE");
        response.setHeader("Access-Control-Allow-Headers", "token, Content-Type");//Authorization是token的key,token是token的key,
        response.setHeader("Access-Control-Max-Age", "3600");
        if ("OPTIONS".equalsIgnoreCase(((HttpServletRequest) req).getMethod())) {
            response.setStatus(HttpServletResponse.SC_OK);
        } else {
            chain.doFilter(req, res);
        }
    }
    @Override
    public void destroy() {
    }
    @Override
    public void init(FilterConfig config) throws ServletException {
    }
}`
``