How to refresh/Update Serialize Java Object in sharedPreferences

问题

For storing the serilaizable java object i m using below code

if(sharedpreferences.getString(ComplexObjectXMl,"")!=null) {

                Serializer serializer = new Persister();
                MyObject example = null;
                try {
                    example = serializer.read(MyObject .class, sharedpreferences.getString(ComplexObjectXMl,""));
                } catch (Exception e) {
                    e.printStackTrace();
                }

                Intent i1 = new Intent(FirstActivity.this, SecondActivity.class);
                startActivity(i1);
            }
                new MyAsyncTask().execute();

In MyAsyncTask i m storing the XmlDataOverHttp in sharedPreferences. Will it get updated everytime if i like do this

回答1:

you can compare byte array of those object. one coming from shared preference and other which is latest.

  byte[] array = new Gson().toJson(latestObject).getBytes(); //your lattest byte array
    byte[] secondArray = new Gson().toJson(objectConvertedFromSharedPreferenceOLD).getBytes();
    if (Arrays.equals(array, secondArray))

        System.out.println("They are same");
else
 System.out.println("Nope...");

and as you said you can use service or shared preference to check hourly update in oncreateView() but it only happens when user open your app(between hour it will call api for list items)

    SharedPreferences mSettings = PreferenceManager.getDefaultSharedPreferences
                (Dashboard.this);
        long lastUpdateTime = mSettings.getLong("lastUpdateTime", 0);
        /* Should Activity Check for Updates Now? */
        if ((lastUpdateTime + (3600000)) < System.currentTimeMillis()) {

        /* Save current timestamp for next Check*/
            SharedPreferences.Editor editor = mSettings.edit();
            lastUpdateTime = System.currentTimeMillis();
            editor.putLong("lastUpdateTime", lastUpdateTime);
            editor.commit();

        /* Start Update for listview your URL to fetch data and then you can check and compare object 
also you can use swipeRefreshLayout so user can also refresh data*/
            //asyncRequestTime.execute(URL);
        }

来源：https://stackoverflow.com/questions/37243996/how-to-refresh-update-serialize-java-object-in-sharedpreferences

标签

android

sharedpreferences