public class CrossDomainFilter implements Filter {

    @Override
    public void init(FilterConfig filterConfig) throws ServletException {
        // TODO Auto-generated method stub
        
    }

    @Override
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
            
 
throws IOException, ServletException {

        HttpServletResponse resp = (HttpServletResponse) response;
        // 允許跨域ajax請求
        resp.setHeader("Access-Control-Allow-Origin", "*");
        resp.setHeader("Access-Control-Allow-Methods", "*");
        resp.setHeader("Access-Control-Allow-Headers", "accept, origin, content-type");
        resp.setHeader(
 
"Content-Type", "application/json;charset=UTF-8");
        
        chain.doFilter(request, resp);
    }

    @Override
    public void destroy() {
        // TODO Auto-generated method stub
        
    }

}

Filter解決ajax跨域問題