ajax跨域，携带cookie

解决方案很简单。

直接上代码：

web.xml中：

添加了 cors来解决跨域

（奇怪的是，credentials设置为false。反正这个是照搬的。。。）

  <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.support.credentials</param-name>
      <param-value>false</param-value>
    </init-param>
  </filter>
  <filter-mapping>
    <filter-name>CorsFilter</filter-name>
    <url-pattern>/*</url-pattern>
  </filter-mapping>

或者在代码中设置：

response.setHeader("Access-Control-Allow-Origin", "*");
		response.setHeader("Access-Control-Allow-Headers", "*");
		response.setHeader("Access-Control-Allow-Methods", "GET, POST");
		response.setHeader("Access-Control-Allow-Credentials", "true");

ajax：

$.ajax({
                type: "post",
                url: "Get",
                crossDomain: true,                 //加这二行支持ajax跨域，允许跨域
                xhrFields: {withCredentials: true},//加这二行支持ajax跨域，携带凭证
                success: function (data) {
                    alert(data);  

                }
            });