action 返回执行js

//LoginAction的提交处理函数：


public String post() throws Exception{
request = ServletActionContext.getRequest();
session=request.getSession();
String code=(String)session.getAttribute("code");  
if(!getCheckcode().equals(code)){  
outJs("验证码错误！","login_form.do");
return null;
}
int i=0;
if("".equals(user.getUsername())||"".equals(user.getPassword())){
outJs("用户名密码不能为空！","login_form.do");
fw=  null;
}else{
i=new UserDao().checkUser(user.getPassword(), user.getUsername());
if(i==0){
outJs("用户名或密码错误，请确认后再填！","login_form.do");
fw= null;
}else{
    user=new UserDao().getUser(i);
    new Auth().save(user);
    if(user.getPri()==1){
fw= "admin";
}else{
    fw= "user";
}
}
}
   return fw;
}

//输出信息的js并跳转：
private void outJs(String msg,String forword){
ActionContext ctx=ActionContext.getContext();
HttpServletResponse response=(HttpServletResponse)ctx.get(org.apache.struts2.StrutsStatics.HTTP_RESPONSE);
response.setContentType("text/html; charset=utf-8");
PrintWriter out=null;  
        try   {  
        String str="<script   type=\"text/javascript\"   language=\"javascript\">";
        out=response.getWriter();   
        str+="alert(\""+msg+"\");";
        str+="window.location.href='"+forword+"'";
        str+="</script>";  
        out.print(str);
        out.close();
}   catch   (IOException   e)   {  
e.printStackTrace();  
}
}