java中获取json的所有key

工作笔记（在不知道json的key时如何获得当前json的keys）

String json="{"name":"angui","age":"23","like":"吃水果"}";
		JSONObject j = JSON.parseObject(json);
		j.remove("age");
		System.out.println(json.toString());
		System.out.println(j.toJSONString());
		
		//将json转换为key=value&key=value&...的情势
		StringBuilder sb = new StringBuilder();
		String sbString="";
		try {
			org.json.JSONObject jsonObject = new org.json.JSONObject(json);
			Iterator iterator = jsonObject.keys();
			while(iterator.hasNext()){
						String key = (String) iterator.next();
			        	sb.append("&"+key);
			        	sb.append("="+jsonObject.getString(key));
			}
			sb.append("&key");
			sbString = sb.substring(1);
		} catch (JSONException e) {
			e.printStackTrace();
		}
		System.out.println(sbString);



String json="