String, JSONArray , JSONObject ,Map<String, Object> 与对象

ArrayList 转化成 JSONArray :

net.sf.json.JSONArray result = JSONArray.fromObject(arrayList);
com.alibaba.fastjson.JSONArray result = JSON.parseArray(JSON.toJSONString(arrayList));

 

 

String pic = "[{\"picServiceUrl\": \"0f4bb44afb2e48d48b786d3bbdeec283/20180408/695329\",\"mainPage\": \"1\",\"name\":null},{\"picServiceUrl\": \"d0a7a8c24c0e463eb9ece1a7076af0e1/20180516/243598\",\"mainPage\": \"0\"}]";

String 可以转化成一个 JSONArray 的数组:

JSONArray array = JSONArray.fromObject(pic);

array 是:  

[{"picServiceUrl":"0f4bb44afb2e48d48b786d3bbdeec283/20180408/695329","mainPage":"1","name":null},{"picServiceUrl":"d0a7a8c24c0e463eb9ece1a7076af0e1/20180516/243598","mainPage":"0"}]

 

array.get(0).getClass().getName() 的类型是 net.sf.json.JSONObject

取出 array 数组中的元素,可以转化成 JSONObject :

JSONObject json = (JSONObject) array.get(0);

json 的值是 : {"picServiceUrl":"0f4bb44afb2e48d48b786d3bbdeec283/20180408/695329","mainPage":"1","name":null}

accumulate 方法 可以给 JSONObject 增加一个key,value 。如果之前对象存在该 key, 则会 把现在的 value 和 之前的 value 组成一个数组,当作该key 的value 值。

json.accumulate("name", 11);

json 的值是: {"picServiceUrl":"0f4bb44afb2e48d48b786d3bbdeec283/20180408/695329","mainPage":"1","name":[null,11]}

 

put 和 element 方法也会给  JSONObject 增加一个key,value 。但是 如果之前对象存在该 key,则会把 之前的value 改成新的 value:

json.put("name", "zhangsan");

json 的值是:{"picServiceUrl":"0f4bb44afb2e48d48b786d3bbdeec283/20180408/695329","mainPage":"1","name":"zhangsan"}

 

获取key的value值:

System.out.println(json.get("picServiceUrl")); 输出:0f4bb44afb2e48d48b786d3bbdeec283/20180408/695329

 

把 String转化成 JSONArray  对象后,也可以把数组中的元素转化成  Map<String, Object> 对象:

String pic = "[{\"picServiceUrl\": \"0f4bb44afb2e48d48b786d3bbdeec283/20180408/695329\",\"mainPage\": \"1\",\"name\":null},{\"picServiceUrl\": \"d0a7a8c24c0e463eb9ece1a7076af0e1/20180516/243598\",\"mainPage\": \"0\"}]";
JSONArray array = JSONArray.fromObject(pic);

Map<String, Object> object = (Map<String, Object>) array.get(0);

System.out.println(object);  // 输出: {"picServiceUrl":"0f4bb44afb2e48d48b786d3bbdeec283/20180408/695329","mainPage":"1","name":12.36}

System.out.println(object.get("picServiceUrl"));  // 输出: 0f4bb44afb2e48d48b786d3bbdeec283/20180408/695329

 

如果 类ServiceGoodsPicture 中含有   private String picServiceUrl;  和   private Boolean mainPage; 两个属性,则 可以把  object 转化成  ServiceGoodsPicture 的一个对象:

 ServiceGoodsPicture entity = ClassUtil.mapToEntity(ServiceGoodsPicture.class, object);

System.out.println(entity);  // entity.toString() 输出: 

ServiceGoodsPicture [Hash = 31, sid=null, serviceId=null, picServiceUrl=0f4bb44afb2e48d48b786d3bbdeec283/20180408/695329, picCreateTime=null, mainPage=true, sort=null, serialVersionUID=1]

 

posted @ 2018-05-16 14:49  zhoudingzhao  阅读(350)  评论(0编辑  收藏  举报