java 请求http文件是否存在

public static int http(String url, String req) {
        DefaultHttpClient httpclient = new DefaultHttpClient();
        HttpPost post = new HttpPost(url);
        List<NameValuePair> params = new ArrayList<NameValuePair>();
        params.add(new BasicNameValuePair("mssage", req));
        try {
            post.setEntity(new UrlEncodedFormEntity(params, HTTP.UTF_8));
            HttpResponse response = httpclient.execute(post);
            int code = response.getStatusLine().getStatusCode();
            return code;
        } catch (Exception e) {
            e.printStackTrace();
        }
        return 0;

    }

public static void main(String[] ages) {

        int retCode = HttpUtil.http(url, "");
        if(retCode != 200){//文件存在
            文件存在
        }else{

            文件不存在

       }

}