前后端分离项目解决跨域问题（后端方式解决）

新建CorsFilter类实现Filter接口，代码如下：

package com.rl.config;

import org.springframework.stereotype.Component;

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


@Component
public class CorsFilter implements Filter {

    final static org.slf4j.Logger logger = org.slf4j.LoggerFactory.getLogger(CorsFilter.class);


    public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain) throws IOException, ServletException {
        HttpServletResponse response = (HttpServletResponse) res;

        HttpServletRequest reqs = (HttpServletRequest) req;

        response.setHeader("Access-Control-Allow-Origin", reqs.getHeader("Origin"));
        response.setHeader("Access-Control-Allow-Credentials", "true");
        response.setHeader("Access-Control-Allow-Methods", "POST, GET, OPTIONS, DELETE");
        response.setHeader("Access-Control-Max-Age", "3600");
        response.setHeader("Access-Control-Allow-Headers", "x-requested-with");
        chain.doFilter(req, res);
    }

    public void init(FilterConfig filterConfig) {
    }

    public void destroy() {
    }
}