ajax跨域问题解决sessionid不一致问题

java的web项目中由于前后台分离导致每次请求springmvc的session都不一样，所以无法在session中保存数据

解决方法：

ajax 跨域请求前台处理，红色字段为ajax处理跨域属性

function  login() {
    $.ajax({
        url:"http://citygame1234.4kb.cn/CityServer/w/login",
        type:"post",
        async:"false",
        dataType:"json"，
        crossDomain: true,
        xhrFields: {
            withCredentials: true
        },
        success:function(data){
            console.log(data);
        }
       
    });
}    

ajax 跨域请求 java后台filter处理

public class MyFilter implements Filter{
@Override
public void destroy() {
}
@Override
public void doFilter(ServletRequest arg0, ServletResponse arg1, FilterChain arg2)
throws IOException, ServletException {
   HttpServletResponse response = (HttpServletResponse) arg1;
   response.setHeader("Access-Control-Allow-Credentials", "true");
   response.setHeader("Access-Control-Allow-Origin", "*");
   response.setHeader("Access-Control-Allow-Methods", "POST,GET,OPTIONS,DELETE");
   response.setHeader("Access-Control-Max-Age", "3600");
 response.setHeader("Access-Control-Allow-Headers", "Origin, Accept, x-auth-token,Content-Type, Access-Control-Request-Method, Access-Control-Request-Headers");
    arg2.doFilter(arg0, arg1);
}
@Override
public void init(FilterConfig arg0) throws ServletException {

}
}

相关网址： https://blog.youkuaiyun.com/djl0906/article/details/70238847