Password Pattern is very necessary when you want to create a secure app system like user management with their data with security. Password Checker or Matcher or Pattern provides a way that how you want to keep your app secure from unauthorized access. Secure App System will provide a reliable connection to the server to your android users. In this tutorial, you will learn the following features: Password Matcher, Password Length, Password Special Character, and Lower and Upper Case and also Numeric Digits. Password Pattern is very useful in the Login and registration system. Using this you can also set Password Length.
How to Create First App in Android Studio Click Here
To Create A Password Strength Checker, Create a new Android Studio Project with empty activity then fill up all the required fields.
Then first of all create a background drawable as shown in the below screenshot:
Right Click on the drawable then select new then choose Drawable Resource File, then choose name as border
then add the below code into this drawable file:
<shape xmlns:android="http://schemas.android.com/apk/res/android"
android:shape="rectangle">
<corners
android:topLeftRadius="30dp"
android:topRightRadius="0dp"
android:bottomRightRadius="30dp"
android:bottomLeftRadius="0dp" />
<stroke
android:width="5dp"
android:color="@color/purple_500" />
</shape>Now copy below line of code and paste it in the activity_main.xml file
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:padding="20sp">
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="Password Checker"
android:gravity="center_horizontal"
android:paddingTop="25sp"
android:textColor="#F40909"
android:textStyle="bold"
android:paddingBottom="20sp"
android:textSize="25sp" />
<LinearLayout
android:orientation="vertical"
android:background="@drawable/border"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:padding="20sp">
<EditText
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:freezesText="true"
android:hint="Enter Password"
android:clickable="true"
android:singleLine="true"
android:textColorHint="@color/black"
android:textColor="@color/red"
android:inputType="textPassword"
android:id="@+id/login_password"
android:padding="10dp"
android:background="@null"/>
<EditText
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:freezesText="true"
android:hint="Confirm Password"
android:clickable="true"
android:singleLine="true"
android:textColorHint="@color/black"
android:textColor="@color/red"
android:inputType="textPassword"
android:id="@+id/confirm_password"
android:padding="10dp"
android:background="@null"/>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal">
<ProgressBar
android:id="@+id/progressBar"
style="?android:attr/progressBarStyleHorizontal"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:indeterminate="false"
android:maxHeight="20dip"
android:minHeight="20dip"
android:layout_weight="1"
android:progress="0"/>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:gravity="center_horizontal"
android:text="Weak"
android:textColor="@color/black"
android:id="@+id/password_strength" />
</LinearLayout>
<Button
android:id="@+id/loginBtn"
android:text="login"
android:textSize="20sp"
android:background="@drawable/border"
android:layout_marginTop="20sp"
android:layout_gravity="center"
android:layout_width="250dp"
android:layout_height="60dp"/>
</LinearLayout>
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:textColor="@color/black"
android:layout_marginTop="10dp"
android:id="@+id/login_instructions"
android:text="Your password must be at least 8 characters. With at least 1 number and 1 special character, 1 Upper case and 1 lowercase" />
</LinearLayout>Now copy the below code and paste it in the MainActivity.java
import androidx.appcompat.app.AppCompatActivity;
import android.os.Bundle;
import android.text.Editable;
import android.text.TextWatcher;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ProgressBar;
import android.widget.TextView;
import android.widget.Toast;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
public class MainActivity extends AppCompatActivity implements TextWatcher {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
EditText password = (EditText)findViewById(R.id.login_password);
EditText cpassword = (EditText)findViewById(R.id.confirm_password);
Button loginNow = (Button) findViewById(R.id.loginBtn);
password.addTextChangedListener(this);
loginNow.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
if(!isValidPassword(password.getText().toString())){
Toast.makeText(MainActivity.this,"Please input valid combination of password!",Toast.LENGTH_LONG).show();
} else if((!password.getText().toString().equals(cpassword.getText().toString()))){
Toast.makeText(MainActivity.this, "Confirm Password Not Matched", Toast.LENGTH_SHORT).show();
} else if((password.getText().toString().equals(cpassword.getText().toString()))) {
Toast.makeText(MainActivity.this, "Login Successful", Toast.LENGTH_SHORT).show();
}
}
});
}
@Override
public void afterTextChanged(Editable s) {
}
@Override
public void beforeTextChanged(
CharSequence s, int start, int count, int after) {
}
@Override
public void onTextChanged(CharSequence s, int start, int before, int count) {
updatePasswordStrengthView(s.toString());
}
private void updatePasswordStrengthView(String password) {
ProgressBar progressBar = (ProgressBar) findViewById(R.id.progressBar);
TextView strengthView = (TextView) findViewById(R.id.password_strength);
if (TextView.VISIBLE != strengthView.getVisibility())
return;
if (password.isEmpty()) {
strengthView.setText("");
progressBar.setProgress(0);
return;
}
if (isValidPassword(password)){
progressBar.setProgress(100);
strengthView.setText("Strong");
} else {
progressBar.setProgress(0);
strengthView.setText("Weak");
}
}
public boolean isValidPassword(final String password) {
Pattern pattern;
Matcher matcher;
final String PASSWORD_PATTERN = "^(?=.*[0-9])(?=.*[a-z])(?=.*[A-Z])(?=.*[@#$%^&+=])(?=\\S+$).{8,}$";
pattern = Pattern.compile(PASSWORD_PATTERN);
matcher = pattern.matcher(password);
return matcher.matches();
}
}Now you are good to go, run it in virtual or real device to test your app.
From the below download link you can download the Source Code, if you have any doubts or problem then feel free to comment below.
