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Trying to enter data in a form in Java before it goes to another form

I have am trying to allow the user to fill in a form in Java after an error message has been displayed indicating that the field is empty. Currently the dialog boxes pop up and then the form goes directly to the next form with out allowing the user to enter anything.
Here is a snippet of the code I am working with:
private void btnEnterActionPerformed(java.awt.event.ActionEvent evt) {
//Confirming that the input fields have values
String un = UserName.getText().toString();
if(un.equals("")) {
JOptionPane.showMessageDialog(null, "Username Required");
}
String pw = Password.getText().toString();
if(pw.equals("")) {
JOptionPane.showMessageDialog(null, "Password Required");
}
//link to HRDBS
HRDBS dbp = new HRDBS();
dbp.setVisible(true);
dbp.pack();
dbp.setLocationRelativeTo(null);
this.dispose();
}
Thank you for your assistance with this matter

it will be a little better if the validation is moved to a separate method and returns on the first error. also you can accumulate errors in one message.
private boolean validateValues() {
String un = UserName.getText().toString();
if(un.equals("")){
JOptionPane.showMessageDialog(null, "Username Required");
return false;
}
String pw = Password.getText().toString();
if(pw.equals("")){
JOptionPane.showMessageDialog(null, "Password Required");
return false;
}
return true;
}
private void btnEnterActionPerformed(java.awt.event.ActionEvent evt) {
//Confirming that the input fields have values
if(validateValues()) {
//link to HRDBS
HRDBS dbp = new HRDBS();
dbp.setVisible(true);
dbp.pack();
dbp.setLocationRelativeTo(null);
this.dispose();
}
}

Android: OnTextChanged email validation is not working as expected

I am using the fololowing code to validate the email input
private boolean validateEmail(String email) {
String emailPattern = "^[a-zA-Z0-9.!#$%&'*+/=?^_`{|}~-]+#((\\[[0-9]{1,3}\\.[0-9]{1,3}\\.[0-9]{1,3}\\.[0-9]{1,3}\\])|(([a-zA-Z\\-0-9]+\\.)+[a-zA-Z]{2,}))$";
Pattern pattern = Pattern.compile(emailPattern);
Matcher matcher = pattern.matcher(email);
return matcher.matches();
}
I execute this on onTextChanged. The code is below (I am using ButterKnife)
#OnTextChanged(R.id.et_email)
public void checkCorrectEmail() {
if (!validateEmail(mEditTextEmail.getText().toString().trim())) {
isValidated = false;
mEditTextEmail.setError("Please enter email address");
mEditTextEmail.requestFocus();
} else {
isValidated = true;
}
}
The issue is that it is not intelligent enough. For an example, if I type myemail#gmail.com it still show the error message. However if I type myemail#gmail.com then a space and clicked delete the space then everything is fine, error gone.
Formerly this validation was on onClick of a button. What have I done wrong here?

#OnTextChanged(R.id.et_email)
public void checkCorrectEmail () {
if (!validateEmail(mEditTextEmail.getText().toString().trim())) {
isValidated = false;
mEditTextEmail.setError("Please enter email address");
mEditTextEmail.requestFocus();
} else {
isValidated = true;
mEditTextEmail.setError(null);
}
}
100% working

Try this :
#OnTextChanged(R.id.et_email)
public void checkCorrectEmail() {
if (!validateEmail(mEditTextEmail.getText().toString().trim())) {
isValidated = false;
mEditTextEmail.setError("Please enter email address");
mEditTextEmail.requestFocus();
} else {
mEditTextEmail.setError(null)
isValidated = true;
}
}
clear the error on correct input

Use the in-build Email pattern checker method:
#OnTextChanged(R.id.et_email)
public void checkCorrectEmail () {
if (!Patterns.EMAIL_ADDRESS.matcher(mEditTextEmail.getText().toString()).matches()){
isValidated = false;
mEditTextEmail.setError("Please enter a Valid E-Mail Address!");
mEditTextEmail.requestFocus();
}else {
isValidated = true;
mEditTextEmail.setError(null);
}

getName method cannot verify JTextField from other class

I wanted to verify my other JTextField using InputVerifier method. What I did I set a named for a different JTextField using setName.
private void validateJTextField()
{
tfAddress.setName("tfAddress");
tfLastName.setInputVerifier(new Validation());
tfFirstName.setInputVerifier(new Validation());
tfMiddleName.setInputVerifier(new Validation());
tfNickname.setInputVerifier(new Validation());
tfAddress.setInputVerifier(new Validation());
}
Validation class
public class Validation extends InputVerifier
{
#Override
public boolean verify(JComponent input)
{
String text = null;
String name = input.getName();
if(input instanceof JTextField)
{
text = ((JTextField) input).getText();
if(text.trim().length() == 0 || text.equals(""))
{
JOptionPane.showMessageDialog(null, "Cannot left blank");
return false;//Return false if the component need to keep focus
}
else
{
try
{
Double.parseDouble(text);
JOptionPane.showMessageDialog(null, "Cannot insert numeric");
return false;
}
catch(NumberFormatException e)
{
}
}
if(text.equals("") && name.equals("tfAddress"))
{
System.out.print("This is tfAddress");
return false;
}
}
return true;//Return true if the component should give up focus
}
}
As you can see here I'm trying to validate or check if name String is equals to "tfAddress" but unfortunately it won't met the condition. Any help or tips how can I solve this?

Here in you code this statement if(text.equals("") && name.equals("tfAddress")) will never satisfied, because of if(text.trim().length() == 0 || text.equals("")) check, so text.equals("") will never return true so name.equals("tfAddress") will skip.
In the first check of if clause if the text is empty, then the code will return. So here if(text.equals("") && name.equals("tfAddress")) you can check for if(name.equals("tfAddress"))

I just solved the problem. I made a mistake on the logic. I based on the text.trim().length() == 0 || text.equals("") so when I the program runs It check first if text is empty. What I did I set the condition based on the setName method. Hoping this will help to others.
private void validateJTextField()
{
tfLastName.setName("tfLastName");
tfFirstName.setName("tfFirstName");
tfMiddleName.setName("tfMiddleName");
tfNickname.setName("tfNickname");
tfAddress.setName("tfAddress");
tfContact.setName("tfContact");
tfLastName.setInputVerifier(new Validation());
tfFirstName.setInputVerifier(new Validation());
tfMiddleName.setInputVerifier(new Validation());
tfNickname.setInputVerifier(new Validation());
tfAddress.setInputVerifier(new Validation());
tfContact.setInputVerifier(new Validation());
}
public class Validation extends InputVerifier
{
#Override
public boolean verify(JComponent input)
{
String text = null;
String cb = null;
String name = input.getName();
if(input instanceof JTextField)
{
text = ((JTextField) input).getText();
if(name.equals("tfLastName") || name.equals("tfFirstName") || name.equals("tfMiddleName") || name.equals("tfNickname"))
{
if(text.trim().length() == 0 || text.equals(""))
{
JOptionPane.showMessageDialog(null, "Cannot left blank");
return false;//Return false if the component need to keep focus
}
else
{
try
{
Double.parseDouble(text);
JOptionPane.showMessageDialog(null, "Cannot insert numeric");
return false;
}
catch(NumberFormatException e)
{
}
}
}
else if(name.equals("tfAddress"))
{
if(text.trim().length() == 0 || text.equals(""))
{
JOptionPane.showMessageDialog(null, "Cannot left blank");
return false;//Return false if the component need to keep focus
}
}
}

How to check password with String in Android

For my application login I want use this library : https://github.com/alphamu/PinEntryEditText
In this library for check password use below method :
final PinEntryEditText pinEntry = (PinEntryEditText) findViewById(R.id.txt_pin_entry);
if (pinEntry != null) {
pinEntry.setOnPinEnteredListener(new PinEntryEditText.OnPinEnteredListener() {
#Override
public void onPinEntered(CharSequence str) {
if (str.toString().equals("1234")) {
Toast.makeText(AnimatedEditTextWidgetsActivity.this, "SUCCESS", Toast.LENGTH_SHORT).show();
} else {
Toast.makeText(AnimatedEditTextWidgetsActivity.this, "FAIL", Toast.LENGTH_SHORT).show();
pinEntry.setText(null);
}
}
});
}
Check with String constructor :
public void onPinEntered(CharSequence str) { ... }
But my query for check password this :
public Boolean login(String password, SQLiteDatabase db) throws SQLException {
Cursor cursor = db.rawQuery("SELECT * FROM " + UserContract.NewUserInfo.TABLE_NAME +
" WHERE " + UserContract.NewUserInfo.USER_PASSWORD + "=?", new String[]{password});
if (cursor != null) {
if (cursor.getCount() > 0) {
return true;
}
}
return false;
}
How can I check password from SQLite with CharSequence str in above library ?!
Please edit my code, because I am amateur and I really need this tutorial. Thanks all <3

As String implements CharSequence you can use a String anywhere you need CharSequence -- to get a String from a CharSequence use toString():
public void onPinEntered(CharSequence str) {
if( login( str.toString() ) {
Toast.makeText(AnimatedEditTextWidgetsActivity.this, "SUCCESS", Toast.LENGTH_SHORT).show();
} else {
Toast.makeText(AnimatedEditTextWidgetsActivity.this, "FAIL", Toast.LENGTH_SHORT).show();
pinEntry.setText(null);
}
}
Tips:
Use boolean instead of Boolean if you don't need a nullable result.
You generally don't want to do heavy lifting on the UI thread. You'll probably get away with running a quick sqlite query, but your UI will become unresponsive if you do longer operations.

How do I use contains to search through a custom object ArrayList for a particular string?

I'm completely brand new to programming (started yesterday...) and Java so excuse any stupid mistakes and really awful code (I have no clue how to order/format). I've been given a task to make an inventory of videos and I want to be able to search through the inventory to check if a particular video is there.
I know I can use contains to do this but I can't get it to work with my custom objects ArrayList (videos) and I want it to search through all the data (each InventoryRow below). I've overridden equals and HashCode but it still won't work - whenever I try to run the code it will always tell me it can't find the video even if the video is there. (FYI I use contains towards the end of my code under the rent and check functions)
I'd really appreciate any help as I've been googling all day to no avail. Also if this can't be done or another method would be better please let me know! Thanks.
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.*;
class InventoryRow {
#Override
public int hashCode() {
final int prime = 31;
int result = 1;
result = prime * result
+ ((availability == null) ? 0 : availability.hashCode());
result = prime * result + ((name == null) ? 0 : name.hashCode());
result = prime * result
+ ((returndate == null) ? 0 : returndate.hashCode());
result = prime * result + ((type == null) ? 0 : type.hashCode());
return result;
}
#Override
public boolean equals(Object obj) {
if (this == obj)
return true;
if (obj == null)
return false;
if (getClass() != obj.getClass())
return false;
InventoryRow other = (InventoryRow) obj;
if (availability == null) {
if (other.availability != null)
return false;
} else if (!availability.equals(other.availability))
return false;
if (name == null) {
if (other.name != null)
return false;
} else if (!name.equals(other.name))
return false;
if (returndate == null) {
if (other.returndate != null)
return false;
} else if (!returndate.equals(other.returndate))
return false;
if (type == null) {
if (other.type != null)
return false;
} else if (!type.equals(other.type))
return false;
return true;
}
private String name;
private String type;
private Character availability;
private String returndate;
public InventoryRow(String name, String type, Character availability,
String returndate) {
this.name = name;
this.type = type;
this.availability = availability;
this.returndate = returndate;
}
public String getReturndate() {
return returndate;
}
public void setReturndate(String returndate) {
this.returndate = returndate;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getType() {
return type;
}
public void setType(String type) {
this.type = type;
}
public Character getAvailability() {
return availability;
}
public void setAvailability(Character availability) {
this.availability = availability;
}
public String toString() {
return name + " " + type + " " + availability + " " + returndate;
}
}
public class InventorySort {
public static void main(String[] args) {
List<InventoryRow> videos = new ArrayList<InventoryRow>();
videos.add(new InventoryRow("Casablanca", "Old", 'Y', "1 January 2015"));
videos.add(new InventoryRow("Jurassic Park", "Regular", 'N',
"1 January 2015"));
videos.add(new InventoryRow("2012", "Regular", 'Y', "1 January 2015"));
videos.add(new InventoryRow("Ant-Man", "New", 'Y', "1 January 2015"));
// Another ArrayList because I can't seem to search through the first
// one?
/*ArrayList<String> names = new ArrayList<String>();
names.add("Casablanca");
names.add("Jurassic Park");
names.add("2012");
names.add("Ant-Man");*/
Scanner input = new Scanner(System.in);
// Output the prompt
System.out.println("What do you want to do?");
// Wait for the user to enter a line of text
String line = input.nextLine();
// List, rent and check functions
// List function
if (line.equals("l")) {
// Sort function
Collections.sort(videos, new Comparator<InventoryRow>() {
public int compare(InventoryRow o1, InventoryRow o2) {
return o1.getName().compareTo(o2.getName());
}
});
for (InventoryRow inventory : videos) {
System.out.println(inventory);
}
// Rent function
} else if (line.equals("r")) {
System.out.println("Which video would you like to rent?");
String line2 = input.nextLine();
// Search through ArrayList
if (videos.contains(line2)) {
System.out.println("Video available to rent!");
} else {
System.out.println("Video unavailable to rent.");
}
// Check function
} else if (line.equals("c")) {
System.out
.println("Which video would you like to check is in the inventory?");
String line3 = input.nextLine();
// Search through ArrayList
if (videos.contains(line3)) {
System.out.println("Video found!");
} else {
System.out
.println("Video not found. Please see the inventory below.");
Collections.sort(videos, new Comparator<InventoryRow>() {
public int compare(InventoryRow o1, InventoryRow o2) {
return o1.getName().compareTo(o2.getName());
}
});
for (InventoryRow inventory : videos) {
System.out.println(inventory);
}
}
// If anything else is entered
} else {
System.out
.println("The only options are to list (l), rent (r) or check (c).");
}
}
}

You can use contains. But, for the first day of programming, it might be more understandable to simply iterate over your inventory, comparing the input string with the video name:
boolean foundIt = false;
for (InventoryRow ir : videos) {
if (line3.equals(ir.getName())) {
foundIt = true;
break;
}
}
if (foundIt) {
System.out.println("Video found!");

Alternative to #kilo answer, you could implement equals and hashcode method only on the name of video class and check it in the following way.
String line3 = input.nextLine();
// Search through ArrayList
if (videos.contains(new Video(line3, null, null, null))) {
System.out.println("Video found!");
}
This will return contains = true only if the name matches.