I'm trying to build a simple app that takes in data and outputs it as a CSV.
Everything is working, but now I am at the point where I am outputting the CSV. When I add the string declarations, I get this error:
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'android.view.Window$Callback android.view.Window.getCallback()' on a null object reference
But when the debugger names my MainActivity it references the line my strings begin on. I really have no idea what I'm doing wrong and am admittedly very new to this.
Here is my code:
package com.tscmusa.pkelley.gpsform;
import android.content.Intent;
import android.icu.text.SimpleDateFormat;
import android.os.Build;
import android.support.annotation.RequiresApi;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.ViewFlipper;
import android.view.MotionEvent;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import java.util.Date;
public class MainActivity extends AppCompatActivity {
private ViewFlipper viewFlipper;
private float lastX;
// File exist
EditText sub;
EditText casenumber;
EditText customer;
EditText date;
EditText po;
String fileName = (sub + "," + date);
Button btnOk;
Button btnReturn;
/*
String sub = ((EditText)findViewById(R.id.txtSubject)).getText().toString();
String casenumber = ((EditText)findViewById(R.id.txtCaseNumber)).getText().toString();
String customer = ((EditText)findViewById(R.id.txtCustomer)).getText().toString();
String date = ((EditText)findViewById(R.id.txtDate)).getText().toString();
String po = ((EditText)findViewById(R.id.txtPO)).getText().toString();
String plate1 = ((EditText)findViewById(R.id.txtPlate1)).getText().toString();
String boxnumber1 = ((EditText)findViewById(R.id.txtBox1)).getText().toString();
String label1 = ((EditText)findViewById(R.id.txtLabel1)).getText().toString();
String make1 = ((EditText)findViewById(R.id.txtMake1)).getText().toString();
String model1 = ((EditText)findViewById(R.id.txtModel1)).getText().toString();
String year1 = ((EditText)findViewById(R.id.txtYear1)).getText().toString();
String odo1 = ((EditText)findViewById(R.id.txtODO1)).getText().toString();
String vin1 = ((EditText)findViewById(R.id.txtVIN1)).getText().toString();
String notes1 = ((EditText)findViewById(R.id.txtNotes1)).getText().toString();
String plate2 = ((EditText)findViewById(R.id.txtPlate2)).getText().toString();
String boxnumber2 = ((EditText)findViewById(R.id.txtBox2)).getText().toString();
String label2 = ((EditText)findViewById(R.id.txtLabel2)).getText().toString();
String make2 = ((EditText)findViewById(R.id.txtMake2)).getText().toString();
String model2 = ((EditText)findViewById(R.id.txtModel2)).getText().toString();
String year2 = ((EditText)findViewById(R.id.txtYear2)).getText().toString();
String odo2 = ((EditText)findViewById(R.id.txtODO2)).getText().toString();
String vin2 = ((EditText)findViewById(R.id.txtVIN2)).getText().toString();
String notes2 = ((EditText)findViewById(R.id.txtNotes2)).getText().toString();
String plate3 = ((EditText)findViewById(R.id.txtPlate3)).getText().toString();
String boxnumber3 = ((EditText)findViewById(R.id.txtBox3)).getText().toString();
String label3 = ((EditText)findViewById(R.id.txtLabel3)).getText().toString();
String make3 = ((EditText)findViewById(R.id.txtMake3)).getText().toString();
String model3 = ((EditText)findViewById(R.id.txtModel3)).getText().toString();
String year3 = ((EditText)findViewById(R.id.txtYear3)).getText().toString();
String odo3 = ((EditText)findViewById(R.id.txtODO3)).getText().toString();
String vin3 = ((EditText)findViewById(R.id.txtVIN3)).getText().toString();
String notes3 = ((EditText)findViewById(R.id.txtNotes3)).getText().toString();
String plate4 = ((EditText)findViewById(R.id.txtPlate4)).getText().toString();
String boxnumber4 = ((EditText)findViewById(R.id.txtBox4)).getText().toString();
String label4 = ((EditText)findViewById(R.id.txtLabel4)).getText().toString();
String make4 = ((EditText)findViewById(R.id.txtMake4)).getText().toString();
String model4 = ((EditText)findViewById(R.id.txtModel4)).getText().toString();
String year4 = ((EditText)findViewById(R.id.txtYear4)).getText().toString();
String odo4 = ((EditText)findViewById(R.id.txtODO4)).getText().toString();
String vin4 = ((EditText)findViewById(R.id.txtVIN4)).getText().toString();
String notes4 = ((EditText)findViewById(R.id.txtNotes4)).getText().toString();
String plate5 = ((EditText)findViewById(R.id.txtPlate5)).getText().toString();
String boxnumber5 = ((EditText)findViewById(R.id.txtBox5)).getText().toString();
String label5 = ((EditText)findViewById(R.id.txtLabel5)).getText().toString();
String make5 = ((EditText)findViewById(R.id.txtMake5)).getText().toString();
String model5 = ((EditText)findViewById(R.id.txtModel5)).getText().toString();
String year5 = ((EditText)findViewById(R.id.txtYear5)).getText().toString();
String odo5 = ((EditText)findViewById(R.id.txtODO5)).getText().toString();
String vin5 = ((EditText)findViewById(R.id.txtVIN5)).getText().toString();
String notes5 = ((EditText)findViewById(R.id.txtNotes5)).getText().toString();
String plate6 = ((EditText)findViewById(R.id.txtPlate5)).getText().toString();
String boxnumber6 = ((EditText)findViewById(R.id.txtBox5)).getText().toString();
String label6 = ((EditText)findViewById(R.id.txtLabel5)).getText().toString();
String make6 = ((EditText)findViewById(R.id.txtMake5)).getText().toString();
String model6 = ((EditText)findViewById(R.id.txtModel5)).getText().toString();
String year6 = ((EditText)findViewById(R.id.txtYear5)).getText().toString();
String odo6 = ((EditText)findViewById(R.id.txtODO5)).getText().toString();
String vin6 = ((EditText)findViewById(R.id.txtVIN5)).getText().toString();
String notes6 = ((EditText)findViewById(R.id.txtNotes5)).getText().toString();
String subject = (date + (" ") + sub);
String fileName = (subject);
*/
@RequiresApi(api = Build.VERSION_CODES.N)
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
viewFlipper = (ViewFlipper) findViewById(R.id.viewFlipper);
sub = (EditText) findViewById(R.id.txtSubject);
casenumber = (EditText) findViewById(R.id.txtCaseNumber);
customer = (EditText) findViewById(R.id.txtCustomer);
date = (EditText) findViewById(R.id.txtDate);
po = (EditText) findViewById(R.id.txtPO);
Intent p1 = getIntent();
final String plate1 = p1.getStringExtra("pl1");
Intent bn1 = getIntent();
final String boxnumber1 = bn1.getStringExtra("bon1");
Intent lb1 = getIntent();
final String label1 = lb1.getStringExtra("lbl1");
Intent ma1 = getIntent();
final String make1 = ma1.getStringExtra("mak1");
Intent mo1 = getIntent();
final String model1 = mo1.getStringExtra("mod1");
Intent y1 = getIntent();
final String year1 = y1.getStringExtra("ye1");
Intent o1 = getIntent();
final String odo1 = o1.getStringExtra("od1");
Intent v1 = getIntent();
final String vin1 = v1.getStringExtra("vi1");
Intent n1 = getIntent();
final String notes1 = n1.getStringExtra("no1");
Button btnOk = (Button) findViewById(R.id.btnOK);
Button btnReturn = (Button) findViewById(R.id.btnReturn);
btnReturn.setOnClickListener(new View.OnClickListener()
{
public void onClick(View v) {
viewFlipper.showPrevious();
}
}
);
btnOk.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
try {
String content = "Technician" + "," + "Case #" + "," + "Customer" + "," + "Date" + "," + "PO" + "/n"
+ sub.getText().toString() + "," + casenumber.getText().toString() + "," + customer.getText().toString() + "," + date.getText().toString() + "," + po.getText().toString() + "/n" +
"Plate" + "," + "Box Number" + "," + "Label" + "," + "Make" + "Model" + "," + "Year" + "," + "ODO" + "," + "VIN" + "," + "Notes" + "/n"
+ plate1 + "," + boxnumber1 + "," + label1 + "," + make1 + "," + model1 + "," + year1 + "," + odo1 + "," + vin1 + "," + notes1 + "/n";
File file = new File(fileName +".csv");
/* if file doesnt exists, then create it */
if (!file.exists()) {
file.createNewFile();
}
FileWriter fw = new FileWriter(file.getAbsoluteFile());
BufferedWriter bw = new BufferedWriter(fw);
bw.write(content);
bw.close();
} catch (IOException e) {
e.printStackTrace();
}
}
});
if (!isTaskRoot()) {
Intent intent = getIntent();
String action = intent.getAction();
if (intent.hasCategory(Intent.CATEGORY_LAUNCHER) && action != null && action.equals(Intent.ACTION_MAIN)) {
finish();
return;
}
}
EditText txtDate = (EditText) findViewById( R.id.txtDate );
SimpleDateFormat sdf = null;
if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.N) {
sdf = new SimpleDateFormat( "yyyy/MM/dd" );
}
txtDate.setText( sdf.format( new Date() ));
String[] deviceList = {"Device 1", "Device 2", "Device 3", "Device 4", "Device 5", "Device 6", "Device 7", "Device 8", "Device9", "Device 10", "Device 11", "Device 12", "Device 13", "Device 14", "Device 15"};
ListAdapter theAdapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, deviceList);
ListView theListView = (ListView) findViewById(R.id.theListView);
theListView.setAdapter(theAdapter);
theListView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> adapterView, View view, int position, long id) {
if (position==0)
{
Intent intent = new Intent(MainActivity.this,Device1.class);
startActivity(intent);
}
if (position==1)
{
Intent intent = new Intent(MainActivity.this,Device2.class);
startActivity(intent);
}
if (position==2)
{
Intent intent = new Intent(MainActivity.this,Device3.class);
startActivity(intent);
}
if (position==3)
{
Intent intent = new Intent(MainActivity.this,Device4.class);
startActivity(intent);
}
if (position==4)
{
Intent intent = new Intent(MainActivity.this,Device5.class);
startActivity(intent);
}
if (position==5)
{
Intent intent = new Intent(MainActivity.this,Device6.class);
startActivity(intent);
}
if (position==6)
{
Intent intent = new Intent(MainActivity.this,Device7.class);
startActivity(intent);
}
if (position==7)
{
Intent intent = new Intent(MainActivity.this,Device8.class);
startActivity(intent);
}
if (position==8)
{
Intent intent = new Intent(MainActivity.this,Device9.class);
startActivity(intent);
}
if (position==9)
{
Intent intent = new Intent(MainActivity.this,Device10.class);
startActivity(intent);
}
if (position==10)
{
Intent intent = new Intent(MainActivity.this,Device11.class);
startActivity(intent);
}
if (position==11)
{
Intent intent = new Intent(MainActivity.this,Device12.class);
startActivity(intent);
}
if (position==12)
{
Intent intent = new Intent(MainActivity.this,Device13.class);
startActivity(intent);
}
if (position==13)
{
Intent intent = new Intent(MainActivity.this,Device14.class);
startActivity(intent);
}
if (position==14)
{
Intent intent = new Intent(MainActivity.this,Device15.class);
startActivity(intent);
}
}
});
}
public boolean onTouchEvent(MotionEvent touchevent) {
switch (touchevent.getAction()) {
case MotionEvent.ACTION_DOWN:
lastX = touchevent.getX();
break;
case MotionEvent.ACTION_UP:
float currentX = touchevent.getX();
// Handling left to right screen swap.
if (lastX < currentX) {
// If there aren't any other children, just break.
if (viewFlipper.getDisplayedChild() == 0)
break;
// Next screen comes in from left.
viewFlipper.setInAnimation(this, R.anim.slide_in_from_left);
// Current screen goes out from right.
viewFlipper.setOutAnimation(this, R.anim.slide_out_to_right);
// Display next screen.
viewFlipper.showNext();
}
// Handling right to left screen swap.
if (lastX > currentX) {
// If there is a child (to the left), kust break.
if (viewFlipper.getDisplayedChild() == 1)
break;
// Next screen comes in from right.
viewFlipper.setInAnimation(this, R.anim.slide_in_from_right);
// Current screen goes out from left.
viewFlipper.setOutAnimation(this, R.anim.slide_out_to_left);
// Display previous screen.
viewFlipper.showPrevious();
}
break;
}
return false;
}
}
I've been trying to make this work by transferring the strings from my other classes but to no avail. Here is the example from Device1.class:
package com.tscmusa.pkelley.gpsform;
import android.content.Intent;
import android.content.SharedPreferences;
import android.os.Parcelable;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.EditText;
public class Device1 extends AppCompatActivity {
public void BacktoMain(View view)
{
Intent intent = new Intent(Device1.this, MainActivity.class);
startActivity(intent);
}
EditText plate1;
EditText boxnumber1;
EditText label1;
EditText make1;
EditText model1;
EditText year1;
EditText odo1;
EditText vin1;
EditText notes1;
private boolean mMyBoolean;
@Override
public void onSaveInstanceState(Bundle savedInstanceState) {
savedInstanceState.putBoolean("MyBoolean", mMyBoolean);
// ... save more data
super.onSaveInstanceState(savedInstanceState);
}
@Override
public void onRestoreInstanceState(Bundle savedInstanceState) {
super.onRestoreInstanceState(savedInstanceState);
mMyBoolean = savedInstanceState.getBoolean("MyBoolean");
// ... recover more data
}
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_device1);
plate1 = (EditText) findViewById(R.id.txtPO);
Intent p1 = new Intent(this, MainActivity.class);
p1.putExtra("pl1", plate1.getText().toString());
startActivity(p1);
boxnumber1 = (EditText) findViewById(R.id.txtBox1);
Intent bn1 = new Intent(this, MainActivity.class);
bn1.putExtra("bon1", boxnumber1.getText().toString());
startActivity(bn1);
label1 = (EditText) findViewById(R.id.txtLabel1);
Intent lb1 = new Intent(this, MainActivity.class);
lb1.putExtra("lbl1", label1.getText().toString());
startActivity(lb1);
make1 = (EditText) findViewById(R.id.txtMake1);
Intent ma1 = new Intent(this, MainActivity.class);
ma1.putExtra("mak1", make1.getText().toString());
startActivity(ma1);
model1 = (EditText) findViewById(R.id.txtModel1);
Intent mo1 = new Intent(this, MainActivity.class);
mo1.putExtra("mod1", model1.getText().toString());
startActivity(mo1);
year1 = (EditText) findViewById(R.id.txtYear1);
Intent y1 = new Intent(this, MainActivity.class);
y1.putExtra("ye1", year1.getText().toString());
startActivity(y1);
odo1 = (EditText) findViewById(R.id.txtODO1);
Intent o1 = new Intent(this, MainActivity.class);
o1.putExtra("od1", odo1.getText().toString());
startActivity(o1);
vin1 = (EditText) findViewById(R.id.txtVIN1);
Intent v1 = new Intent(this, MainActivity.class);
v1.putExtra("vi1", vin1.getText().toString());
startActivity(v1);
notes1 = (EditText) findViewById(R.id.txtNotes1);
Intent n1 = new Intent(this, MainActivity.class);
n1.putExtra("no1", notes1.getText().toString());
startActivity(n1);
if (!isTaskRoot()) {
Intent intent = getIntent();
String action = intent.getAction();
if (intent.hasCategory(Intent.CATEGORY_LAUNCHER) && action != null && action.equals(Intent.ACTION_MAIN)) {
finish();
return;
}
}
}
}
Any help would be very greatly appreciated.
You cannot have this initialization here:
String vin1 = ((EditText)findViewById(R.id.txtVIN1)).getText().toString();
You can declare your variable there like: EditText vin1;
And then in onCreate AFTER calling setContentView put the initialization like:
vin1 = (EditText) findViewById(R.id.txtVIN1);
Then when you need call vin1.getText().toString();