JSONObject Not Serializable?

Sheehan Alam picture Sheehan Alam · May 7, 2011 · Viewed 40.9k times · Source

I am trying to serialize an ArrayList of JSONObjects. But I get the error:

05-07 01:04:24.130: WARN/System.err(913): java.io.NotSerializableException: org.json.JSONObject
05-07 01:04:24.130: WARN/System.err(913):     at java.io.ObjectOutputStream.writeNewObject(ObjectOutputStream.java:1535)
05-07 01:04:24.130: WARN/System.err(913):     at java.io.ObjectOutputStream.writeObjectInternal(ObjectOutputStream.java:1847)
05-07 01:04:24.130: WARN/System.err(913):     at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:1689)
05-07 01:04:24.130: WARN/System.err(913):     at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:1653)
05-07 01:04:24.130: WARN/System.err(913):     at java.util.ArrayList.writeObject(ArrayList.java:651)
05-07 01:04:24.130: WARN/System.err(913):     at java.lang.reflect.Method.invokeNative(Native Method)
05-07 01:04:24.130: WARN/System.err(913):     at java.lang.reflect.Method.invoke(Method.java:507)
05-07 01:04:24.130: WARN/System.err(913):     at java.io.ObjectOutputStream.writeHierarchy(ObjectOutputStream.java:1219)
05-07 01:04:24.130: WARN/System.err(913):     at java.io.ObjectOutputStream.writeNewObject(ObjectOutputStream.java:1575)
05-07 01:04:24.130: WARN/System.err(913):     at java.io.ObjectOutputStream.writeObjectInternal(ObjectOutputStream.java:1847)
05-07 01:04:24.130: WARN/System.err(913):     at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:1689)
05-07 01:04:24.130: WARN/System.err(913):     at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:1653)
05-07 01:04:24.130: WARN/System.err(913):     at org.stocktwits.activity.AddStocksActivity.serializeQuotes(AddStocksActivity.java:183)
05-07 01:04:24.130: WARN/System.err(913):     at org.stocktwits.activity.AddStocksActivity.access$9(AddStocksActivity.java:178)
05-07 01:04:24.130: WARN/System.err(913):     at org.stocktwits.activity.AddStocksActivity$2.onItemClick(AddStocksActivity.java:146)
05-07 01:04:24.130: WARN/System.err(913):     at android.widget.AdapterView.performItemClick(AdapterView.java:284)
05-07 01:04:24.130: WARN/System.err(913):     at android.widget.ListView.performItemClick(ListView.java:3513)
05-07 01:04:24.130: WARN/System.err(913):     at android.widget.AbsListView$PerformClick.run(AbsListView.java:1812)
05-07 01:04:24.130: WARN/System.err(913):     at android.os.Handler.handleCallback(Handler.java:587)
05-07 01:04:24.130: WARN/System.err(913):     at android.os.Handler.dispatchMessage(Handler.java:92)
05-07 01:04:24.130: WARN/System.err(913):     at android.os.Looper.loop(Looper.java:130)
05-07 01:04:24.130: WARN/System.err(913):     at android.app.ActivityThread.main(ActivityThread.java:3683)
05-07 01:04:24.130: WARN/System.err(913):     at java.lang.reflect.Method.invokeNative(Native Method)
05-07 01:04:24.130: WARN/System.err(913):     at java.lang.reflect.Method.invoke(Method.java:507)
05-07 01:04:24.130: WARN/System.err(913):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
05-07 01:04:24.130: WARN/System.err(913):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
05-07 01:04:24.130: WARN/System.err(913):     at dalvik.system.NativeStart.main(Native Method)

Here is my serialize & deserialize code:

private void serializeQuotes() {
        FileOutputStream fos;
        try {
            fos = openFileOutput(Constants.FILENAME, Context.MODE_PRIVATE);
            ObjectOutputStream oos = new ObjectOutputStream(fos);
            oos.writeObject(quotes);
            oos.close();
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    @SuppressWarnings("unchecked")
    private void deserializeQuotes() {
        try {
            FileInputStream fis = openFileInput(Constants.FILENAME);
            ObjectInputStream ois = new ObjectInputStream(fis);
            quotes = (ArrayList<JSONObject>) ois.readObject();
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        }
    }

Answer

Thane Anthem picture Thane Anthem · May 7, 2011

Dude, it's JSON. Why not just serialize it as JSON, instead of as a Java object of type JSONObject?

For example:

String myJsonObjectSerialized = myJsonObject.toString();