前后端项目的跨域问题解决

方案一：在后端代码中配置Fiilter过滤器解决跨域问题

@WebFilter(filterName = "kuaYuFilter", urlPatterns = "/*")
public class kuayuFilter 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;
        // 不使⽤*，⾃动适配跨域域名，避免携带Cookie时失效
        String origin = request.getHeader("Origin");
        response.setHeader("Access-Control-Allow-Origin", origin);
        // ⾃适应所有⾃定义头
        String headers = request.getHeader("Access-Control-Request-Headers");
        response.setHeader("Access-Control-Allow-Headers", headers);
        response.setHeader("Access-Control-Expose-Headers", headers);
        // 允许跨域的请求⽅法类型
        response.setHeader("Access-Control-Allow-Methods", "*");
        // 预检命令（OPTIONS）缓存时间，单位：秒
        response.setHeader("Access-Control-Max-Age", "3600");
        // 明确许可客户端发送Cookie，不允许删除字段即可
        response.setHeader("Access-Control-Allow-Credentials", "true");

        filterChain.doFilter(request, response);

    }
    @Override
    public void destroy() {

    }
}