Someone marked this question as duplicate(What is a NullPointerException, and how do I fix it?), but that didn't help at all. I'm reposting the question.
//
I'm just learning myself and pretty new to android programming and java. I'm trying to get list from a txt file which is located in internal storage.
This is what I have done.
try {
path = getFilesDir().getAbsolutePath() ;
FileInputStream inFs = new FileInputStream(new File(path.toString() + "/filesitem_" + Type + ".txt"));
byte[] txt = new byte[inFs.available()];
while (inFs.read(txt) != -1) {}
String[] list_item = new String(txt).split(",");
item_actv = (MultiAutoCompleteTextView) dlgView.findViewById(R.id.Item_AutoTxtView);
ArrayAdapter<String> adapter = new ArrayAdapter<>(this, android.R.layout.simple_dropdown_item_1line, list_item);
MultiAutoCompleteTextView.CommaTokenizer token = new MultiAutoCompleteTextView.CommaTokenizer();
item_actv.setTokenizer(token);
item_actv.setAdapter(adapter);
} catch (IOException e) {
Toast.makeText(Activity_list.this, "No item list.", Toast.LENGTH_SHORT).show();
}
itemQuant_np = (NumberPicker) dlgView.findViewById(R.id.ItemQuant_Np);
itemQuant_np.setMinValue(1);
itemQuant_np.setMaxValue(10);
SimpleDateFormat formater = new SimpleDateFormat("yyyy-mm-dd", Locale.KOREA);
Date current = new Date();
date = formater.format(current);
AlertDialog.Builder dlg2 = new AlertDialog.Builder(Activity_list.this)
.setTitle("New List")
.setView(dlgView)
.setPositiveButton("Confirm", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialogInterface, int i) {
try {
path = getFilesDir().getAbsolutePath() + "/" + Type + "_list";
FileOutputStream outFs = new FileOutputStream(new File(path + "/" + date + " list_" + Type + ".txt"), true);
listContent = item_actv.getText().toString() + "\t\t\t" + Integer.toString(itemQuant_np.getValue()) + "\n";
outFs.write(listContent.getBytes());
outFs.close();
Toast.makeText(Activity_list.this, "Saved.", Toast.LENGTH_SHORT).show();
} catch (IOException e) {
Toast.makeText(Activity_list.this, "The file is already exist.", Toast.LENGTH_SHORT).show();
}
}
})
.setNegativeButton("Cancel", null);
dlg2.show();
This dialog shows up when I click a item on a menu.
What it supposed to do is that the diglog would show up, and as I enter a name of item into MultiAutoCompleteTextView, it will show me available list which is from a txt file already saved in internal storage. In the txt file, there are list of items separated by comma(ex: apple,grape,orange). If I hit the Confirm button on the dialog after I fill MultiAutoCompleteTextView and set quantity of the item, it will create a new txt file into designated path.
The diglog shows up correctly, but the issues are
- the app stops when I hit "Confirm" button on the dialog (Unfortunately, the app has stopped)
(java.lang.NullPointerException: Attempt to invoke virtual method 'android.text.Editable android.widget.MultiAutoCompleteTextView.getText()' on a null object reference)
- seems like it is not getting auto completion list for MultiAutoCompleteTextView
- it creates new txt file, but the content is empty
I really need your help :(
+Activity.java
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setTitle("Manage snacks");
setContentView(R.layout.subactivity);
Intent intent = getIntent();
Type = intent.getStringExtra("Type");
fileList = (ListView) findViewById(R.id.FileList);
arFiles = new ArrayList<>();
File file = new File(getFilesDir().getAbsolutePath() + "/" + Type + "_list");
arFiles.addAll(Arrays.asList(file.list()));
flAdapter = new ArrayAdapter<>(this, android.R.layout.simple_list_item_1, arFiles);
fileList.setAdapter(flAdapter);
fileList.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
String name = arFiles.get(i);
Intent intent = new Intent(Activity_list.this, Activity_listspec.class);
intent.putExtra("Type", Type);
intent.putExtra("fileName", name);
startActivity(intent);
}
});
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
super.onCreateOptionsMenu(menu);
menu.add(0, 1, 0, "Add new item");
menu.add(0, 2, 0, "Add new list");
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case 1:
dlgView = View.inflate(Activity_list.this, R.layout.dlg_newitem, null);
edtTxtNewItem = (EditText) dlgView.findViewById(R.id.EdtTxtNewItem);
AlertDialog.Builder dlg1 = new AlertDialog.Builder(Activity_list.this)
.setTitle("New item")
.setView(dlgView)
.setPositiveButton("Confirm", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialogInterface, int i) {
try {
path = getFilesDir().getAbsolutePath();
FileOutputStream outFs = new FileOutputStream(new File(path + "item_" + Type + ".txt"), true);
itemList = edtTxtNewItem.getText().toString() + ",";
outFs.write(itemList.getBytes());
outFs.close();
Toast.makeText(getApplicationContext(), edtTxtNewItem.getText().toString() + " Item added.", 0).show();
} catch (IOException e) {
e.printStackTrace();
}
}
})
.setNegativeButton("Cancel", null);
dlg1.show();
return true;
case 2:
dlgView = View.inflate(Activity_list.this, R.layout.dlg_newlist, null);
try {
path = getFilesDir().getAbsolutePath() ;
FileInputStream inFs = new FileInputStream(new File(path.toString() + "/filesitem_" + Type + ".txt"));
byte[] txt = new byte[inFs.available()];
while (inFs.read(txt) != -1) {}
String[] list_item = new String(txt).split(",");
item_actv = (MultiAutoCompleteTextView) dlgView.findViewById(R.id.Item_AutoTxtView);
ArrayAdapter<String> adapter = new ArrayAdapter<>(this, android.R.layout.simple_dropdown_item_1line, list_item);
MultiAutoCompleteTextView.CommaTokenizer token = new MultiAutoCompleteTextView.CommaTokenizer();
item_actv.setTokenizer(token);
item_actv.setAdapter(adapter);
} catch (IOException e) {
Toast.makeText(Activity_list.this, "No existing list.", Toast.LENGTH_SHORT).show();
}
itemQuant_np = (NumberPicker) dlgView.findViewById(R.id.ItemQuant_Np);
itemQuant_np.setMinValue(1);
itemQuant_np.setMaxValue(10);
SimpleDateFormat formater = new SimpleDateFormat("yyyy-mm-dd", Locale.KOREA);
Date current = new Date();
date = formater.format(current);
AlertDialog.Builder dlg2 = new AlertDialog.Builder(Activity_list.this)
.setTitle("New List")
.setView(dlgView)
.setPositiveButton("Confirm", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialogInterface, int i) {
try {
path = getFilesDir().getAbsolutePath() + "/" + Type + "_list";
FileOutputStream outFs = new FileOutputStream(new File(path + "/" + date + " list_" + Type + ".txt"), true);
listContent = item_actv.getText().toString() + "\t\t\t" + Integer.toString(itemQuant_np.getValue()) + "\n";
outFs.write(listContent.getBytes());
outFs.close();
Toast.makeText(Activity_list.this, "Saved.", Toast.LENGTH_SHORT).show();
} catch (IOException e) {
Toast.makeText(Activity_list.this, "The file is already exist.", Toast.LENGTH_SHORT).show();
}
}
})
.setNegativeButton("Cancel", null);
dlg2.show();
return true;
}
return false;
}
}
subactivity.xml
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent">
<ListView
android:id="@+id/FileList"
android:layout_width="match_parent"
android:layout_height="match_parent">
</ListView>
</LinearLayout>
dlg_newitem.xml
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:gravity="center">
<EditText
android:id="@+id/EdtTxtNewItem"
android:hint="상품명"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_margin="20dp"/>
</LinearLayout>
dlg_newlist.xml
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="horizontal"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:gravity="center">
<MultiAutoCompleteTextView
android:id="@+id/Item_AutoTxtView"
android:hint="상품명"
android:completionThreshold="3"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_weight="1"
android:layout_marginLeft="20dp"
android:layout_marginRight="10dp"/>
<NumberPicker
android:id="@+id/ItemQuant_Np"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_margin="10dp">
</NumberPicker>
</LinearLayout>
