问题
I'm trying to get Company id (&& Company name) in first activity, pass it into the second activity and there I'd like to retrieve all data from database based on that id (&& name), but the app crashes, below is the code. can someone provide me a working code snippet. Any kind of help will be appreciated.
AdapterCompany
public class AdapterCompany extends RecyclerView.Adapter<AdapterCompany.AdapterCompanyHolder> {
private List<EntityCompany> entityCompanies = new ArrayList<>();
private CompanyClickListener listener;
public AdapterCompany(CompanyClickListener listener) {
this.listener = listener;
}
@NonNull
@Override
public AdapterCompanyHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
View itemView = LayoutInflater.from(parent.getContext())
.inflate(R.layout.company_list, parent, false);
return new AdapterCompanyHolder(itemView, listener);
}
@Override
public void onBindViewHolder(@NonNull AdapterCompanyHolder holder, int position) {
EntityCompany currentEntityCompany = entityCompanies.get(position);
holder.textViewCompany.setText(currentEntityCompany.getCompany());
holder.textViewCompanyName.setText(currentEntityCompany.getCompany_name());
holder.textViewCompanyDescription.setText(currentEntityCompany.getCompany_short_description());
holder.imageViewCompanySrc.setImageURI(Uri.parse("android.resource://com.example.handyman/drawable/" + currentEntityCompany.getCompany_image_src()));
}
@Override
public int getItemCount() {
return entityCompanies.size();
}
public void setEntityCompanies(List<EntityCompany> entityCompanies) {
this.entityCompanies = entityCompanies;
notifyDataSetChanged();
}
public static class AdapterCompanyHolder extends RecyclerView.ViewHolder implements View.OnClickListener {
private CompanyClickListener listener;
private TextView textViewCompany, textViewCompanyName, textViewCompanyDescription;
private ImageView imageViewCompanySrc;
public AdapterCompanyHolder(@NonNull View itemView, CompanyClickListener listener) {
super(itemView);
this.listener = listener;
itemView.setOnClickListener(this);
textViewCompany = itemView.findViewById(R.id.textViewCompany);
textViewCompanyName = itemView.findViewById(R.id.textViewCompanyName);
textViewCompanyDescription = itemView.findViewById(R.id.textViewCompanyDescription);
imageViewCompanySrc = itemView.findViewById(R.id.imageViewCompanySrc);
}
@Override
public void onClick(View view) {
if (listener != null) {
listener.onCompanyClick(getAdapterPosition());
}
}
}
interface CompanyClickListener {
void onCompanyClick(int position);
}
}
RepositoryCompany
public class RepositoryCompany {
private DaoCompany daoCompany;
private LiveData<List<EntityCompany>> allEntityCompany;
public RepositoryCompany(Application application) {
DatabaseHandyman databaseHandyman = DatabaseHandyman.getInstance(application);
daoCompany = databaseHandyman.daoCompany();
allEntityCompany = daoCompany.getAllEntityCompany();
}
public void insert(EntityCompany entityCompany) {
new InsertEntityCompanyAsyncTask(daoCompany).execute(entityCompany);
}
public void update(EntityCompany entityCompany) {
new UpdateEntityCompanyAsyncTask(daoCompany).execute(entityCompany);
}
public void delete(EntityCompany entityCompany) {
new DeleteEntityCompanyAsyncTask(daoCompany).execute(entityCompany);
}
public LiveData<List<EntityCompany>> getAllEntityCompany() {
return allEntityCompany;
}
private static class InsertEntityCompanyAsyncTask extends AsyncTask<EntityCompany, Void, Void> {
private DaoCompany daoCompany;
private InsertEntityCompanyAsyncTask(DaoCompany daoCompany) {
this.daoCompany = daoCompany;
}
@Override
protected Void doInBackground(EntityCompany... entityCompanies) {
daoCompany.insert(entityCompanies[0]);
return null;
}
}
private static class UpdateEntityCompanyAsyncTask extends AsyncTask<EntityCompany, Void, Void> {
private DaoCompany daoCompany;
private UpdateEntityCompanyAsyncTask(DaoCompany daoCompany) {
this.daoCompany = daoCompany;
}
@Override
protected Void doInBackground(EntityCompany... entityCompanies) {
daoCompany.update(entityCompanies[0]);
return null;
}
}
private static class DeleteEntityCompanyAsyncTask extends AsyncTask<EntityCompany, Void, Void> {
private DaoCompany daoCompany;
private DeleteEntityCompanyAsyncTask(DaoCompany daoCompany) {
this.daoCompany = daoCompany;
}
@Override
protected Void doInBackground(EntityCompany... entityCompanies) {
daoCompany.delete(entityCompanies[0]);
return null;
}
}
}
ViewModelCompany
public class ViewModelCompany extends AndroidViewModel {
private RepositoryCompany repositoryCompany;
private LiveData<List<EntityCompany>> allEntityCompany;
public ViewModelCompany(@NonNull Application application) {
super(application);
repositoryCompany = new RepositoryCompany(application);
allEntityCompany = repositoryCompany.getAllEntityCompany();
}
public void insert(EntityCompany entityCompany) {
repositoryCompany.insert(entityCompany);
}
public void update(EntityCompany entityCompany) {
repositoryCompany.update(entityCompany);
}
public void delete(EntityCompany entityCompany) {
repositoryCompany.delete(entityCompany);
}
public LiveData<List<EntityCompany>> getAllEntityCompany() {
return allEntityCompany;
}
}
MainActivity
public class MainActivity extends AppCompatActivity implements AdapterCompany.CompanyClickListener {
private List<EntityCompany> entityCompanies = new ArrayList<>();
private ViewModelCompany viewModelCompany;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
RecyclerView recyclerView = findViewById(R.id.recycler_view);
recyclerView.setLayoutManager(new LinearLayoutManager(this));
recyclerView.setHasFixedSize(true);
final AdapterCompany adapter = new AdapterCompany(this);
recyclerView.setAdapter(adapter);
viewModelCompany = new ViewModelProvider(this).get(ViewModelCompany.class);
viewModelCompany.getAllEntityCompany().observe(this, new Observer<List<EntityCompany>>() {
@Override
public void onChanged(List<EntityCompany> entityCompanies) {
adapter.setEntityCompanies(entityCompanies);
}
});
}
@Override
public void onCompanyClick(int position) {
EntityCompany entityCompany = entityCompanies.get(position);
CompanyInformation.open(this, entityCompany.getId());
// Intent intent = new Intent(this, CompanyInformation.class);
// startActivity(intent);
}
}
CompanyInformation
public class CompanyInformation extends AppCompatActivity {
public static void open(MainActivity mainActivity, long entityCompanyId) {
Intent intent = new Intent(mainActivity, CompanyInformation.class);
intent.putExtra("CompanyId", entityCompanyId);
mainActivity.startActivity(intent);
}
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_company_information);
Intent intent = getIntent();
if (intent !=null && intent.hasExtra("CompanyId")) {
long entityCompanyId = intent.getLongExtra("CompanyId", -1 );
Toast.makeText(this, "Company Id is " + entityCompanyId, Toast.LENGTH_SHORT).show();
}
}
}
Error
2020-06-27 11:01:34.937 12524-12524/com.example.handyman E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.handyman, PID: 12524
java.lang.IndexOutOfBoundsException: Index: 1, Size: 0
at java.util.ArrayList.get(ArrayList.java:437)
at com.example.handyman.MainActivity.onCompanyClick(MainActivity.java:52)
at com.example.handyman.AdapterCompany$AdapterCompanyHolder.onClick(AdapterCompany.java:76)
at android.view.View.performClick(View.java:6294)
at android.view.View$PerformClick.run(View.java:24770)
at android.os.Handler.handleCallback(Handler.java:790)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:164)
at android.app.ActivityThread.main(ActivityThread.java:6494)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:438)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:807)
来源：https://stackoverflow.com/questions/62607969/room-database-recyclerview-how-to-pass-data-to-another-activity-and-then-retr