Enable geoserver to serve frond end and overcome the CORS problem

 Go to geoserver\lib in the lib directory of geoserve to find jetty-servlets-XX.jar and jetty-util-xx.jar (xx means different versions) two jar packages

Copy the all jars packagesfrom geoserver\lib to the geoserver\webapps\geoserver\WEB-INF\lib\ directory

 Go to the geoserver\webapps\geoserver\WEB-INF directory to find web.xml and add the following XML:

<context-param>

    <param-name>ENABLE_JSONP</param-name>

    <param-value>true</param-value>

</context-param>

<filter>

      <filter-name>cross-origin</filter-name>

      <filter-class>org.eclipse.jetty.servlets.CrossOriginFilter</filter-class>

  </filter>

   <filter-mapping>

        <filter-name>cross-origin</filter-name>

        <url-pattern>/*</url-pattern>

    </filter-mapping>

add the following line at the beginning of startup file of geoserver   

"C:\Program Files\GeoServer\bin\startup.bat" edit it by notepad++

set geoserver.xframe.shouldSetPolicy=false

or using the service 

open the wrapper folder C:\Program Files\GeoServer\wrapper

and edit the cmd command which placed at the end of the jsl64 file

-Dgeoserver.xframe.shouldSetPolicy=false

stop the service and run the startup.bat as administrator

Everything will be OK