java判断字符串是什么编码

java判断字符串是什么编码，然后转换成中文：

	response.setContentType("text/html;charset=utf-8"); 
        request.setCharacterEncoding("utf-8");
        response.setCharacterEncoding("utf-8");
        String name=Tool.ObjToStr(request.getParameter("name"), "美国");
        if(name.equals(new String(name.getBytes("iso8859-1"), "iso8859-1"))){
		name=new String(request.getParameter("name").getBytes("iso8859-1"),"utf-8");
        }