后台程序控制js弹出框

public void jsWindow(String msg, int i){
HttpServletResponse response=ServletActionContext.getResponse();
try {
response.setContentType("text/html;charset=UTF-8");
response.setCharacterEncoding("UTF-8");
response.setHeader("Cache-Control", "no-cache");
PrintWriter out = response.getWriter();
out.println("<script language='javascript'>");
out.println("alert('"+msg+"')");
out.println("history.go("+i+")");
out.println("</script>");
out.flush();
} catch (IOException e) {
e.printStackTrace();
}

}

}