简洁和清晰的层次结构使得 JSON 成为理想的数据交换语言,它易于人阅读和编写,同时也易于机器解析和生成,并有效地提升网络传输效率。那json数据怎么解析?下面来我们就来给大家讲解一下。
一、JSON解析之传统的JSON解析
1、生成json字符串
public static String createJsonString(String key, Object value) { JSONObject jsonObject = new JSONObject(); jsonObject.put(key, value); return jsonObject.toString(); }
2、解析JSON字符串
分为以下三种情况,一个JavaBean,一个List数组,一个嵌套Map的List数组:
import java.util.ArrayList; import java.util.HashMap; import java.util.Iterator; import java.util.List; import java.util.Map; import org.json.JSONArray; import org.json.JSONObject; import com.android.myjson.domain.Person; /** * 完成对json数据的解析 * */ public class JsonTools { public static Person getPerson(String key, String jsonString) { Person person = new Person(); try { JSONObject jsonObject = new JSONObject(jsonString); JSONObject personObject = jsonObject.getJSONObject("person"); person.setId(personObject.getInt("id")); person.setName(personObject.getString("name")); person.setAddress(personObject.getString("address")); } catch (Exception e) { // TODO: handle exception } return person; } public static List getPersons(String key, String jsonString) { List list = new ArrayList(); try { JSONObject jsonObject = new JSONObject(jsonString); // 返回json的数组 JSONArray jsonArray = jsonObject.getJSONArray(key); for (int i = 0; i < jsonArray.length(); i++) { JSONObject jsonObject2 = jsonArray.getJSONObject(i); Person person = new Person(); person.setId(jsonObject2.getInt("id")); person.setName(jsonObject2.getString("name")); person.setAddress(jsonObject2.getString("address")); list.add(person); } } catch (Exception e) { // TODO: handle exception } return list; } public static List getList(String key, String jsonString) { List list = new ArrayList(); try { JSONObject jsonObject = new JSONObject(jsonString); JSONArray jsonArray = jsonObject.getJSONArray(key); for (int i = 0; i < jsonArray.length(); i++) { String msg = jsonArray.getString(i); list.add(msg); } } catch (Exception e) { // TODO: handle exception } return list; } public static List > listKeyMaps(String key , String jsonString) { List > list = new ArrayList > (); try { JSONObject jsonObject = new JSONObject(jsonString); JSONArray jsonArray = jsonObject.getJSONArray(key); for (int i = 0; i < jsonArray.length(); i++) { JSONObject jsonObject2 = jsonArray.getJSONObject(i); Map map = new HashMap(); Iterator iterator = jsonObject2.keys(); while (iterator.hasNext()) { String json_key = iterator.next(); Object json_value = jsonObject2.get(json_key); if (json_value == null) { json_value = ""; } map.put(json_key, json_value); } list.add(map); } } catch (Exception e) { // TODO: handle exception } return list; } }
二、JSON解析之GSON
1、生成JSON字符串
import com.google.gson.Gson; public class JsonUtils { public static String createJsonObject(Object obj) { Gson gson = new Gson(); String str = gson.toJson(obj); return str; } }
2、解析JSON
import java.util.ArrayList; import java.util.List; import java.util.Map; import com.google.gson.Gson; import com.google.gson.reflect.TypeToken;; public class GsonTools { public GsonTools() { // TODO Auto-generated constructor stub } /** * @param * @param jsonString * @param cls * @return */ public static T getPerson(String jsonString, Class cls) { T t = null; try { Gson gson = new Gson(); t = gson.fromJson(jsonString, cls); } catch (Exception e) { // TODO: handle exception } return t; } /** * 使用Gson进行解析 List * * @param * @param jsonString * @param cls * @return */ public static List getPersons(String jsonString, Class cls) { List list = new ArrayList(); try { Gson gson = new Gson(); list = gson.fromJson(jsonString, new TypeToken > () {}.getType()); } catch (Exception e) {} return list; } /** * @param jsonString * @return */ public static List getList(String jsonString) { List list = new ArrayList(); try { Gson gson = new Gson(); list = gson.fromJson(jsonString, new TypeToken > () {}.getType()); } catch (Exception e) { // TODO: handle exception } return list; } public static List > listKeyMaps(String jsonString) { List > list = new ArrayList > (); try { Gson gson = new Gson(); list = gson.fromJson(jsonString , new TypeToken >> () {}.getType()); } catch (Exception e) { // TODO: handle exception } return list; } }
三、JSON解析之FastJSON
import java.util.ArrayList; import java.util.List; import java.util.Map; import com.alibaba.fastjson.JSON; import com.alibaba.fastjson.TypeReference; public class JsonTool { public static T getPerson(String jsonstring, Class cls) { T t = null; try { t = JSON.parseObject(jsonstring, cls); } catch (Exception e) { // TODO: handle exception } return t; } public static List getPersonList(String jsonstring, Class cls) { List list = new ArrayList(); try { list = JSON.parseArray(jsonstring, cls); } catch (Exception e) { // TODO: handle exception } return list; } public static List > getPersonListMap1( String jsonstring) { List > list = new ArrayList > (); try { list = JSON.parseObject(jsonstring , new TypeReference >> () {}.getType()); } catch (Exception e) { // TODO: handle exception } return list; } }
Json解析可以通过以上三种方法,我们可以任选一种对json进行解析,json解析过后的数据易于人们理解以及阅读,是一种轻量级的数据交换格式。最后大家如果想要了解更多json工具教程知识,敬请关注奇Q工具网。
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