我曾多次遇到CORS问题,通常可以解决它,但我想通过从MEAN堆栈范式中看到这一点来真正理解。

之前我只是在我的快速服务器中添加了中间件来捕获这些东西,但它看起来像有某种预挂钩,使我的请求出错。

在preflight响应中,Access-Control-Allow-Headers不允许请求报头字段Access-Control-Allow-Headers

我假设我可以这样做:

app.use(function(req, res, next) {
  res.header("Access-Control-Allow-Headers","*")
})

或者等价的,但这似乎不能解决问题。我当然也试过

app.use(function(req, res, next) {
  res.header("Access-Control-Allow-Headers","Access-Control-Allow-Headers")
})

还是不走运。


当前回答

这是你需要添加的使它工作。

response.setHeader("Access-Control-Allow-Origin", "*");
response.setHeader("Access-Control-Allow-Credentials", "true");
response.setHeader("Access-Control-Allow-Methods", "GET,HEAD,OPTIONS,POST,PUT");
response.setHeader("Access-Control-Allow-Headers", "Access-Control-Allow-Headers, Origin,Accept, X-Requested-With, Content-Type, Access-Control-Request-Method, Access-Control-Request-Headers");

The browser sends a preflight request (with method type OPTIONS) to check if the service hosted on the server is allowed to be accessed from the browser on a different domain. In response to the preflight request if you inject above headers the browser understands that it is ok to make further calls and i will get a valid response to my actual GET/POST call. you can constraint the domain to which access is granted by using Access-Control-Allow-Origin", "localhost, xvz.com" instead of * . ( * will grant access to all domains)

其他回答

将这些头添加到ajax或js函数中

headers: {
            "Cache-Control": null,
            "X-Requested-With": null,
        }

res.setHeader(‘Access-Control-Allow-Headers’,‘*’);

消息是明确的,“授权”是不允许在API。集 Access-Control-Allow-Headers: "Content-Type, Authorization"

如果您试图在请求标头上添加自定义标头,则必须让服务器知道允许发生特定的标头。在过滤请求的类中执行此操作。在下面的例子中,自定义头名称为"type":

public class CorsFilter implements Filter {
    @Override
    public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain) throws IOException, ServletException {
        HttpServletRequest request = (HttpServletRequest) req;
        HttpServletResponse response = (HttpServletResponse) res;
        response.setHeader("Access-Control-Allow-Origin",  request.getHeader("Origin"));
        response.setHeader("Access-Control-Allow-Credentials", "true");
        response.setHeader("Access-Control-Allow-Methods", "GET,PUT,POST,DELETE,PATCH,OPTIONS");
        response.setHeader("Access-Control-Max-Age", "3600");
        response.setHeader("Access-Control-Allow-Headers", "Content-Type, Accept, X-Requested-With, remember-me, Authorization, type ");
        response.setHeader("Access-Control-Expose-Headers","Authorization");
    }
}

这是你需要添加的使它工作。

response.setHeader("Access-Control-Allow-Origin", "*");
response.setHeader("Access-Control-Allow-Credentials", "true");
response.setHeader("Access-Control-Allow-Methods", "GET,HEAD,OPTIONS,POST,PUT");
response.setHeader("Access-Control-Allow-Headers", "Access-Control-Allow-Headers, Origin,Accept, X-Requested-With, Content-Type, Access-Control-Request-Method, Access-Control-Request-Headers");

The browser sends a preflight request (with method type OPTIONS) to check if the service hosted on the server is allowed to be accessed from the browser on a different domain. In response to the preflight request if you inject above headers the browser understands that it is ok to make further calls and i will get a valid response to my actual GET/POST call. you can constraint the domain to which access is granted by using Access-Control-Allow-Origin", "localhost, xvz.com" instead of * . ( * will grant access to all domains)