Android: Cannot call private without parameters android.net.Uri()… here is a solution to the problem.
Android: Cannot call private without parameters android.net.Uri()
I’m using Gson to save an array list of custom models to a shared preference
Storage Code:
ArrayList<DownloadProgressDataModel> arrayList = getArrayListFromPref(downloadProgressDataModel);
SharedPreferences.Editor prefsEditor = getSharedPreferences("APPLICATION_PREF", MODE_PRIVATE).edit();
Gson gson = new Gson();
String json = gson.toJson(arrayList);
prefsEditor.putString("DownloadManagerList", json);
prefsEditor.apply();
}
Retrieve
ArrayList<DownloadProgressDataModel> arrayList;
Gson gson = new Gson();
SharedPreferences mPrefs = getSharedPreferences("APPLICATION_PREF", MODE_PRIVATE);
String json = mPrefs.getString("DownloadManagerList", "");
if (json.isEmpty()) {
arrayList = new ArrayList<DownloadProgressDataModel>();
} else {
Type uriPath = new TypeToken<ArrayList<DownloadProgressDataModel>>() {
}.getType();
arrayList = gson.fromJson(json, uriPath); <------ Error line
}
But on the error line I get: Unable to instantiate class android.net.Uri
Model number
public class DownloadProgressDataModel {
private Uri uriPath;
private long referenceId;
public Uri getUriPath() {
return uriPath;
}
public void setUriPath(Uri uriPath) {
this.uriPath = uriPath;
}
public long getReferenceId() {
return referenceId;
}
public void setReferenceId(long referenceId) {
this.referenceId = referenceId;
}
}
Solution
The Uri class constructor is private, it is an abstract class. Gson tries to create a new object for the Uri class using the
reflection API (we can’t create an object for an abstract class). Such a simple solution is to change the uriPath
to a String
instead of a URI
.
private String uriPath;