java web项目Session获取不到问题及解决

String url=response.encodeRedirectURL("url");
response.sendRedirect(url);

<%=request.getSession().getAttribute("key")%>

import axiOS from 'axios';
axios.defaults.withCredentials=true;

<filter>
    <filter-name>contextFilter</filter-name>
    <filter-class>com.zl.filter.ContextFilter</filter-class>
</filter>
<filter-mapping>
    <filter-name>contextFilter</filter-name>
    <url-pattern>/*</url-pattern>
</filter-mapping>

public class ContextFilter implements Filter {
    @Override
    public void init(FilterConfig filterConfig) throws ServletException {
    }
    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        httpservletResponse response = (HttpServletResponse)servletResponse;
        HttpServletRequest request = (HttpServletRequest)servletRequest;
        String origin = request.getHeader("Origin");
        response.setHeader("Access-Control-Allow-Origin", origin);
        response.setHeader("Access-Control-Allow-Methods", "*");
        String headers = request.getHeader("Access-Control-Request-Headers");
         // 支持所有自定义头
        if (!org.springframework.util.StringUtils.isEmpty(headers)) {
            response.setHeader("Access-Control-Allow-Headers", headers);
        }
        response.setHeader("Access-Control-Allow-Credentials", "true");
        response.setHeader("Access-Control-Max-Age", "3600");
        filterChain.doFilter(request, response);
    }
    @Override
    public void destroy() {
    }
}