the url in html:

```
<a href=""////jrdc.xxx.com/dh/nc?camp=19&mid=19&mat=121&unit=-&uuid=386931bea19dbba0e8f8c3291743d004a71669b5807d3eb49e150e08fcd93c83&aid=12&day=1493864666856&to=https://sale.xxx.com/act/UuzWBLwPKX.html" target="_blank">

```

the contronller:

```
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public void clickLog(HttpServletRequest request, HttpServletResponse response) {
    try {
        // 
        String targetUrl = request.getParameter("to");         
       if(targetUrl != null && !targetUrl.contains("http")){
           targetUrl = "http://" + targetUrl;
       }
       response.sendRedirect(targetUrl);
    }catch (Exception e){

    }finally {

    }

}

```

the targetUrl to response.sendRedirect() is :

https://sale.jd.com/act/UuzWBLwPKX.html

the question is when redirect:
the url in chrome browser becomes:

```
https://sale.xxx.com//act//UuzWBLwPKX.html

```

which the "/" before "act" becomes "//", I don't want this result, why becomes this and how to become <https://sale.xxx.com/act/UuzWBLwPKX.html>