Json,Gson,FastJson解析笔记

Json

1.将JavaBean转换成Json对象：

public static String CreatJsonFromObject(Object key,Object value)
    {
        JSONObject JObj =new JSONObject();
        JObj.put(key, value);
        return JObj.toString();
    }

2.解析Json：

public static  Person parseJsonPerson(String key,String jsonStr)
  {
      System.out.print(key+"-->"+jsonStr);
      Person person =new Person();
      JSONObject jobj;
      try
      {
          jobj = new JSONObject(jsonStr);
          JSONObject personObj =jobj.getJSONObject(key);
          person.setAge(personObj.getInt("age"));
          person.setName(personObj.getString("name"));
          person.setSex(personObj.getString("sex"));
      }
      catch (JSONException e)
      {
          e.printStackTrace();
      }
      return person;

  }

  public static List<Person> parseJsonListPerson(String key,String jsonStr)
  {
      System.out.print(key+"-->"+jsonStr);
      List<Person> list=new ArrayList<Person>();
      try
      {
          JSONObject jobj;
          jobj = new JSONObject(jsonStr);
          JSONArray personArr =jobj.getJSONArray(key);
          for(int i=0;i<personArr.length();i++)
          {
              JSONObject personObj = personArr.getJSONObject(i);
              Person person =new Person();
              person.setAge(personObj.getInt("age"));
              person.setName(personObj.getString("name"));
              person.setSex(personObj.getString("sex"));
              list.add(person);
          }
      }
      catch (JSONException e)
      {
          // TODO Auto-generated catch block
          e.printStackTrace();
      }
      return list;
  }

  public static List<String> parseJsonListString(String key,String jsonStr)
  {
      System.out.print(key+"-->"+jsonStr);
      List<String> list =new ArrayList<String>();
      try
      {
          JSONObject jobj;
          jobj = new JSONObject(jsonStr);
          JSONArray personArr =jobj.getJSONArray(key);
          for(int i=0;i<personArr.length();i++)
          {
              String personObj = personArr.getString(i);
              list.add(personObj);
          }
      }
      catch (JSONException e)
      {
          // TODO Auto-generated catch block
          e.printStackTrace();
      }
      return list;
  }

  public static List<Map<String, Object>> parseJsonListMap(String key,String jsonStr)
  {
      System.out.print(key+"-->"+jsonStr);
      List<Map<String, Object>> list =new ArrayList<Map<String,Object>>();
      try
      {
          JSONObject jobj;
          jobj = new JSONObject(jsonStr);
          JSONArray personArr =jobj.getJSONArray(key);
          for(int i=0;i<personArr.length();i++)
          {
              JSONObject personObj = personArr.getJSONObject(i);
              Iterator<String> set =personObj.keys();
              while(set.hasNext())
              {
                  String tempKey =set.next();
                  Object tempValue =personObj.get(tempKey);
                  HashMap<String,Object> map =new HashMap<String,Object>();
                  //注意tempValue可能为空
                  if(tempValue == null)
                  {
                      tempValue="";
                  }
                  map.put(tempKey, tempValue);
                  list.add(map);
              }
          }

      }
      catch (JSONException e)
      {
          // TODO Auto-generated catch block
          e.printStackTrace();
      }


      return list;
  }

Gson:

1.将JavaBean转换成Gson String

public static String CreatJsonFromObject(Object value)
{
    Gson gson =new Gson();
    return gson.toJson(value);

}

2.解析Gson String

public static <T> T getPerson(String Json, Class<T> cls)
   {
       Gson gson = new Gson();
       T t = gson.fromJson(Json, cls);
       return t;
   }

  public static <T> List<T> getPersons(String Json, Class<T> Type)
   {
       List<T> list = new Gson().fromJson(Json, new TypeToken<List<T>>()
       {
       }.getType());
       return list;
   }

  public  static List<String> getString(String Json)
   {
       List<String> retStr = new Gson().fromJson(Json, new TypeToken<List<String>>()
       {
       }.getType());
       return retStr;
   }

  public   static List<Map<String, Object>> getListMap(String Json)
   {
       List<Map<String, Object>> retStr = new Gson().fromJson(Json, new TypeToken<List<Map<String, Object>>>()
       {
       }.getType());
       return retStr;
   }

FastJson:

1.将JavaBean转换成FastJson String

服务端利用上述方式实现

2.解析FastJson String

public static <T> T getPerson(String jsonStr, Class<T> cls)
   {
       T t = JSON.parseObject(jsonStr, cls);
       return t;
   }

   public static <T> List<T> getPersons(String jsonStr, Class<T> cls)
   {
       List<T> list = JSON.parseArray(jsonStr, cls);
       return list;
   }

   /**
    * @param jsonStr
    * @return
    */
   public static List<Map<String, Object>> getListMap(String jsonStr)
   {
       List<Map<String, Object>> list = JSON.parseObject(jsonStr, new TypeReference<List<Map<String, Object>>>()
       {
       });
       return list;
   }
// from: http://www.voidcn.com/blog/zchlww/article/p-4999460.html