list后台转化为JSON的方法ajax

导入alibaba的fastJson包

后台：

protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		response.setCharacterEncoding("utf-8");
		PrintWriter pw = response.getWriter();
		  List<Map<String, Object>> data = new ArrayList<Map<String, Object>>();
		  Map<String, Object>map=new HashMap<>();
		Fraction f=new Fraction(2,3);
		Fraction f1=new Fraction(4,5);
		map.put("molecular", f.getMolecular());
		map.put("denominator", f.getDenominator());
		data.add(map);
		 Map<String, Object>map1=new HashMap<>();
			map1.put("molecular", f1.getMolecular());
			map1.put("denominator", f1.getDenominator());
			data.add(map1);
			JSONArray array=toJsonArray(data);
			pw.write(array.toString());
			pw.flush();
			pw.close();
	}
	public static JSONArray toJsonArray( List<Map<String, Object>>data){
		JSONArray array =new JSONArray();
		for(Map<String,Object>rowItem:data){
			JSONObject json=new JSONObject();
			try{
				for(Map.Entry<String, Object>entry:rowItem.entrySet()){
					json.put(entry.getKey(), entry.getValue());
				}
			}catch(Exception e){
				e.printStackTrace();
			}
			array.add(json);
		}
		
		return array;
	}

前端：

<script type="text/javascript">
$("#button").click(function(){
	$.ajax({
	type:"post",
	dataType:"json",
	url : "TestServlet",
	success:function(result){
		for(var i=0;i<result.length;i++){
			alert(result[i].molecular+" "+result[i].denominator);
		}
	}
	});	
});

</script>