Android 存储：SharePreferences存储List＜Map＜String,Object＞＞类型数组

Posted 2021-09-17 kaolagirl

建一个ToolUtils工具类，然后在里面分别写存和取的逻辑方法

public class ToolUtils {
   /**
     * setLeftList 设置缓存，存数据
     * @param context
     * @param key
     * @param list
     * @author wang 8/31
     */
    public static void setLeftList(Context context, String key,List<Map<String,Object>> list){
        JSONArray mJsonArray = new JSONArray();
        for(int i=0;i<list.size();i++){
            Map<String,Object> itemMap = list.get(i);
            Iterator<Map.Entry<String,Object>> iterator = itemMap.entrySet().iterator();

            JSONObject object = new JSONObject();
            while (iterator.hasNext()){
                Map.Entry<String,Object> entry = iterator.next();
                try {
                    object.put(entry.getKey(),entry.getValue());
                }catch (JSONException je){
                    je.printStackTrace();
                }
            }
            mJsonArray.put(object);
        }
        SharedPreferences sharedPreferences = context.getSharedPreferences(key,context.MODE_PRIVATE);
        SharedPreferences.Editor shareEditor = sharedPreferences.edit();
        shareEditor.putString(key,mJsonArray.toString());
        shareEditor.commit();
    }

    /**
     * getLeftList 取数据
     * @param context
     * @param key
     * @return
     * @author wang 8/31
     */
    public static List<Map<String,Object>> getLeftList(Context context,String key){
        List<Map<String, Object>> list = new ArrayList<>();
        SharedPreferences sharedPreferences = context.getSharedPreferences(key,context.MODE_PRIVATE);
        String result = sharedPreferences.getString(key,"");
        try{
            JSONArray array = new JSONArray(result);
            for (int i=0;i<array.length();i++){
                JSONObject jsonItem = array.getJSONObject(i);
                Map<String,Object> mapItem = new HashMap<>();
                JSONArray names = jsonItem.names();
                if(names !=null){
                    for(int j=0;j<names.length();j++){
                        String name = names.getString(j);
                        String value = jsonItem.getString(name);
                        mapItem.put(name,value);
                    }
                }
                list.add(mapItem);
            }
        }catch (JSONException je){
            je.printStackTrace();
        }
        return  list;
    }
}

使用

 ToolUtils.setLeftList(getContext(), "leftList", left_list);  //存数据
  List<Map<String,Object>> list = ToolUtils.getLeftList(getContext(),"leftList");  //从缓存中取数据