restful接口跨域问题

HttpServletRequest req；

HttpServletResponse resp

/**     * 对跨域提供支持     */    

resp.setHeader("Access-Control-Allow-Origin", 
req.getHeader("Origin"));    
resp.setHeader("Access-Control-Allow-Methods", "GET,POST,OPTIONS,PUT,DELETE");    
resp.setHeader("Access-Control-Allow-Headers", req.getHeader("Access-Control-Request-Headers"));    
resp.addHeader("Access-Control-Allow-Credentials", "true");    // 跨域时会首先发送一个option请求，这里我们给option请求直接返回正常状态