ajax返回值为中文时乱码解决方法

 /**
	 * 使用ajax检查用户是否存在
	 */
	public void checkUser(){
	
		try{
			System.out.println("userName="+user.getUserName());
	    	HttpServletResponse response=ServletActionContext.getResponse();
	    	response.setContentType("text/xml;charset=utf-8");
	        response.setHeader("Cache-Control", "no-cache");
	     
	    	PrintWriter pw=response.getWriter(); //输出中文，这一句一定要放到response.setContentType("text/xml;charset=utf-8"),  response.setHeader("Cache-Control", "no-cache")后面，否则中文返回到页面是乱码
		  
	    	if(existUser.contains(user.getUserName()))
		    {
		    	pw.print("存在");
		    }else{
		    	pw.print("不存在");
		    }
		 
		    pw.close();
		}catch(IOException e){
			e.printStackTrace();
		}
	}