对飞行前请求的Ajax响应未通过访问控制

Question

我已经找了5个小时左右，但我放弃了。我的ajax get请求不起作用。

var ApiResponce = $.ajax({
    url: "http://localhost:18428/api/Reservation/" + userid + "?weekNumber=" + weeknr,
    type: 'GET',
    headers: {
        'Authorization': "bearer " + token,  
        'Access-Control-Allow-Origin': '*',
        'Access-Control-Allow-Credentials': true,
    },
    dataType: 'json',
    crossDomain: true,
    contentType: "application/json",

    success: function(responce) {
        console.log("success");
        console.log(responce);
    },
    error: function(err) {
      console.log("error");
        console.log(ApiResponce);
    },
});

它连接到标准的C#mvc api，但我得到的只是这个错误：

无法加载XMLHttpRequesthttp://localhost:18428/api/Reservation/1?weekNumber=1. 对飞行前请求的响应未通过访问控制检查：请求的资源上不存在“访问控制允许来源”标头。起源'http://localhost因此，不允许访问。响应的HTTP状态代码为405。

Answer 1

如果在服务器端使用Apache Tomcat，则需要在servlet容器上编辑web.xml文件并添加以下行：

     <filter>
        <filter-name>CorsFilter</filter-name>
        <filter-class>org.apache.catalina.filters.CorsFilter</filter-class>
        <init-param>
                <param-name>cors.allowed.origins</param-name>
                <param-value>*</param-value>
        </init-param>
        <init-param>
                <param-name>cors.allowed.methods</param-name>
                <param-value>GET, HEAD, POST, PUT, DELETE, OPTIONS</param-value>
        </init-param>
        <init-param>
                <param-name>cors.exposed.headers</param-name>
                <param-value>Access-Control-Allow-Origin,Access-Control-Allow-Credentials,X-Bonita-API-Token</param-value>
        </init-param>
        <init-param>
                <param-name>cors.allowed.headers</param-name>
                <param-value>Content-Type,X-Requested-With,accept,Origin,Access-Control-Request-Method,Access-Control-Request-Headers,X-Bonita-API-Token</param-value>
        </init-param>
    </filter>

    <filter-mapping>
        <filter-name>CorsFilter</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>

注意：在ApacheTomcat7中工作，不要忘记重新启动Tomcat。