[Android]用SharedPreferences保存List>数据

时间:2022-05-09 10:37:28

原因:

SharedPreferences没有保存数组的方法,但是有时候为了保存一个数组而进行序列化,或者动用sqlite都是有点杀猪焉用牛刀的感觉,所以就自己动手改进一下吧。

解决方案:

采用的方式是先转换成JSON,然后保存字符串,取出的时候再讲JSON转换成数组就好了。
public void saveInfo(Context context, String key, List<Map<String, String>> datas) {
JSONArray mJsonArray = new JSONArray();
for (int i = 0; i < datas.size(); i++) {
Map<String, String> itemMap = datas.get(i);
Iterator<Entry<String, String>> iterator = itemMap.entrySet().iterator();

JSONObject object = new JSONObject();

while (iterator.hasNext()) {
Entry<String, String> entry = iterator.next();
try {
object.put(entry.getKey(), entry.getValue());
} catch (JSONException e) {

}
}
mJsonArray.put(object);
}

SharedPreferences sp = context.getSharedPreferences("finals", Context.MODE_PRIVATE);
Editor editor = sp.edit();
editor.putString(key, mJsonArray.toString());
editor.commit();
}

public List<Map<String, String>> getInfo(Context context, String key) {
List<Map<String, String>> datas = new ArrayList<Map<String, String>>();
SharedPreferences sp = context.getSharedPreferences("finals", Context.MODE_PRIVATE);
String result = sp.getString(key, "");
try {
JSONArray array = new JSONArray(result);
for (int i = 0; i < array.length(); i++) {
JSONObject itemObject = array.getJSONObject(i);
Map<String, String> itemMap = new HashMap<String, String>();
JSONArray names = itemObject.names();
if (names != null) {
for (int j = 0; j < names.length(); j++) {
String name = names.getString(j);
String value = itemObject.getString(name);
itemMap.put(name, value);
}
}
datas.add(itemMap);
}
} catch (JSONException e) {

}

return datas;
}