跨域請求

@Override
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
        HttpServletResponse httpServletResponse = (HttpServletResponse) response;
        httpServletResponse.setHeader("Access-Control-Allow-Origin", "*");
        httpServletResponse.setCharacterEncoding("utf-8");
        chain.doFilter(request, httpServletResponse);
    }

解決方法就是 在資源的頭中 加入 Access-Control-Allow-Origin 指定你受權的域.

指定星號 * , 就表示任何域均可以訪問個人資源.

若是須要指定某域名才容許跨域訪問，只需把Access-Control-Allow-Origin:*改成Access-Control-Allow-Origin:容許的域名

例如：httpServletResponse.setHeader("Access-Control-Allow-Origin", "http://www.client.com");