Random Password generator in android studio

    How to Make Random Password Generator

Here is the Xml 

<?xml version="1.0" encoding="utf-8"?>

<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"

    xmlns:app="http://schemas.android.com/apk/res-auto"

    xmlns:tools="http://schemas.android.com/tools"

    android:layout_width="match_parent"

    android:layout_height="match_parent"

    tools:context="mriet.deekshith.com.randompassword.MainActivity">

    <Button

        android:id="@+id/button"

        android:layout_width="201dp"

        android:layout_height="wrap_content"

        android:layout_marginBottom="8dp"

        android:layout_marginEnd="8dp"

        android:layout_marginStart="8dp"

        android:layout_marginTop="8dp"

        android:text="generate Passowrd"

        app:layout_constraintBottom_toBottomOf="parent"

        app:layout_constraintEnd_toEndOf="parent"

        app:layout_constraintHorizontal_bias="0.502"

        app:layout_constraintStart_toStartOf="parent"

        app:layout_constraintTop_toTopOf="parent"

        app:layout_constraintVertical_bias="0.653" />

    <TextView

        android:id="@+id/textView"

        android:layout_width="244dp"

        android:layout_height="72dp"

        android:layout_marginBottom="8dp"

        android:layout_marginEnd="8dp"

        android:layout_marginStart="8dp"

        android:layout_marginTop="8dp"

        android:textSize="30sp"

        app:layout_constraintBottom_toBottomOf="parent"

        app:layout_constraintEnd_toEndOf="parent"

        app:layout_constraintStart_toStartOf="parent"

        app:layout_constraintTop_toTopOf="parent"

        app:layout_constraintVertical_bias="0.366" />

</android.support.constraint.ConstraintLayout>

JAVA file 

import android.support.v7.app.AppCompatActivity;

import android.os.Bundle;

import android.view.View;

import android.widget.Button;

import android.widget.TextView;

import java.util.Random;

public class MainActivity extends AppCompatActivity {

    Button button;

    TextView textView;

    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);

        button = (Button)findViewById(R.id.button);

        textView = (TextView)findViewById(R.id.textView);

        button.setOnClickListener(new View.OnClickListener() {

            @Override

            public void onClick(View view) {

                textView.setText(generateString(12));

            }

        });

    }

    private String generateString(int length){

        char[] chars ="QWERTYUIOPASDFGHJKLZXCVBNMmnbvcxzlkjhgfsapoiuytrewq1234567890!@#$%^&*()".toCharArray();

        StringBuilder stringBuilder = new StringBuilder();

        Random random = new Random();

        for ( int i= 0; i<length;i++)

        {

            char c = chars[random.nextInt(chars.length)];

            stringBuilder.append(c);

        }

        return stringBuilder.toString();

    }

}