Javaweb下的跨域问题

       因为浏览器同源访问的限制，前端在使用ajax进行请求时会出现跨域问题，只要端口不一样，主机不一样服务调用必定跨域，在spring里面，有个@CrossOrigin注解能够解决跨域问题，可是在个人实践中发现并很差用前几天用spring boot写后台出现跨域，以前有用的解决方案所有失效，很玄学的问题。如今我想用一种通用的解决方案来实现：

public class OriginFilter implements Filter {
    @Override
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain filterChain) throws IOException, ServletException {
        HttpServletResponse httpServletResponse = (HttpServletResponse) response;
        request.setCharacterEncoding("UTF-8");
        response.setCharacterEncoding("UTF-8");
        // 处理跨域
        httpServletResponse.setHeader("Access-Control-Allow-Origin", "*");
        httpServletResponse.setHeader("Access-Control-Expose-Headers", "*");
        httpServletResponse.setHeader("Access-Control-Allow-Headers", "*");
        httpServletResponse.setHeader("Access-Control-Allow-Methods", "PUT,POST,GET,DELETE,OPTIONS");
        httpServletResponse.setHeader("X-Powered-By", "Tomcat");
        httpServletResponse.setHeader("Content-Type", "text/html;charset=UTF-8");
        httpServletResponse.setHeader("maxAge", "10000");

        request.setAttribute("Access-Control-Request-Headers", "*");
        filterChain.doFilter(request, response);
    }
}

若是是springboot还须要在本类上加注解

@Component
@WebFilter(urlPatterns = "/", filterName = "myOriginFilter")
@Order(1)//指定过滤器的执行顺序,值越大越靠后执行

主类上加上@ServletComponentScan

如果普通javaweb项目写配置文件就好

我的看法：跨域这种安全性问题真的不能交给前端去控制，咱们的前端一直想去用jsonp去解决跨域被我挡回去了，前端真的控制不了安全问题