ajax后台处理响应（java）

public static final void sendAsJson(HttpServletResponse response,String str)  
{  
  response.setContentType("application/json;charset=UTF-8");  
  if (null != str)  
    try {  
      response.getWriter().write(str);  
    } catch (IOException e) {  
      e.printStackTrace();  
    }  
}  

public static final void sendAsText(HttpServletResponse response,String str)  
{  
  response.setContentType("text/html;charset=UTF-8");  
  if (null != str)  
    try {  
      response.getWriter().write(str);  
    } catch (IOException e) {  
      e.printStackTrace();  
    }  
}