前端调用后端接口请求跨域问题

public class CorsFilter implements Filter {

static final String OPTIONS = "OPTIONS";

@Override
public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain)
throws IOException, ServletException {
HttpServletRequest request = (HttpServletRequest) req;
HttpServletResponse response = (HttpServletResponse) res;

// 允许指定域访问跨域资源
response.setHeader("Access-Control-Allow-Origin", "*");
// 允许所有请求方式
response.setHeader("Access-Control-Allow-Methods", "POST, GET, OPTIONS, DELETE");
// 有效时间
response.setHeader("Access-Control-Max-Age", "3600");
// 允许的header参数
response.setHeader("Access-Control-Allow-Headers", "x-requested-with,satoken");

// 如果是预检请求，直接返回
if (OPTIONS.equals(request.getMethod())) {
System.out.println("=======================浏览器发来了OPTIONS预检请求==========");
response.getWriter().print("");
return;
}

// System.out.println("*********************************过滤器被使用**************************");
chain.doFilter(req, res);
}

@Override
public void init(FilterConfig filterConfig) {
}

@Override
public void destroy() {
}

}