How to add elements on ArrayList in Android and display ArrayList data into next activity?

 How to add elements on ArrayList in Android and display ArrayList data into the next activity?

Step1st:-

Create Class and define a property on it's:-

package com.example.additionapplication;

public class Student {
    private int rno;
    private  String sname;
    public  Student(int rno, String sname)
    {
             this.rno=rno;
             this.sname=sname;
    }
    public int getRno() {
        return rno;
    }

    public void setRno(int rno) {
        this.rno = rno;
    }

    public String getSname() {
        return sname;
    }

    public void setSname(String sname) {
        this.sname = sname;
    }
}

Step2nd:-

Create Activity and Design xml file 

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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"
    android:orientation="vertical"
    tools:context=".MainActivity14">

    <EditText
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/txtr1"
        android:hint="Enter rno"
        ></EditText>

    <EditText
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/txtr2"
        android:hint="Enter sname"
        ></EditText>

    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Click"
        android:id="@+id/btnadd"
        ></Button>

    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Final"
        android:id="@+id/btnfinal"
        ></Button>
</LinearLayout>


Step3rd:-
Create .java file and Write code on it to add elements.

package com.example.additionapplication;

import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

import java.util.ArrayList;
import java.util.List;

public class MainActivity14 extends AppCompatActivity {

    EditText txt1,txt2;
    Button btn,btn1;
    List<Student> stu= new ArrayList<Student>();
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main14);
        txt1 = findViewById(R.id.txtr1);
        txt2 = findViewById(R.id.txtr2);
        btn1 = findViewById(R.id.btnadd);
        btn1.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

              stu.add(new Student(Integer.parseInt(txt1.getText().toString()),txt2.getText().toString()));
            }
        });
        btn = findViewById(R.id.btnfinal);
        btn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                for(Student st:stu)
                {
                    Toast.makeText(getApplicationContext(),"Rno is "+st.getRno() + " Name is "+st.getSname(),Toast.LENGTH_LONG).show();
                }
            }
        });
    }
}

ASSIGNMENT 2nd:-

DISPLAY DATA IN SECOND ACTIVITY:-

STEP!ST:-

CREATE POJO CLASS or SERIALIZABLE CLASS:-

1)

package com.example.additionapplication;

import java.io.Serializable;

public class Student implements Serializable {
    private int rno;
    private  String sname;
    public  Student(int rno, String sname)
    {
             this.rno=rno;
             this.sname=sname;
    }


    public int getRno() {
        return rno;
    }

    public void setRno(int rno) {
        this.rno = rno;
    }

    public String getSname() {
        return sname;
    }

    public void setSname(String sname) {
        this.sname = sname;
    }

    public  String toString()
    {
       return  "rno is "+rno + "name is "+sname;
    }
}

2)  Create DESIGn FILE using XML for Source Activity:-

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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"
    android:orientation="vertical"
    tools:context=".MainActivity14">

    <EditText
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/txtr1"
        android:hint="Enter rno"
        ></EditText>

    <EditText
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/txtr2"
        android:hint="Enter sname"
        ></EditText>

    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Click"
        android:id="@+id/btnadd"
        ></Button>

    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Final"
        android:id="@+id/btnfinal"
        ></Button>
</LinearLayout>


3)  CREATE JAVA CODE for SOURCE ACTIVITY TO SET DATA ON LIST:-

package com.example.additionapplication;

import androidx.appcompat.app.AppCompatActivity;

import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

import java.util.ArrayList;
import java.util.List;

public class MainActivity14 extends AppCompatActivity {

    EditText txt1,txt2;
    Button btn,btn1;
    ArrayList<Student> stu= new ArrayList<Student>();
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main14);
        txt1 = findViewById(R.id.txtr1);
        txt2 = findViewById(R.id.txtr2);
        btn1 = findViewById(R.id.btnadd);
        btn1.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

              stu.add(new Student(Integer.parseInt(txt1.getText().toString()),txt2.getText().toString()));
            }
        });
        btn = findViewById(R.id.btnfinal);
        btn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                Intent i = new Intent(getApplicationContext(),MainActivity15.class);
                i.putExtra("data",stu);
                startActivity(i);
               /* for(Student st:stu)
                {
                    Toast.makeText(getApplicationContext(),"Rno is "+st.getRno() + " Name is "+st.getSname(),Toast.LENGTH_LONG).show();
                }*/
            }
        });
    }
}


4)  Create ANOTHER ACTIVITY TO VIEW DATA

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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"
    android:orientation="horizontal"
    tools:context=".MainActivity15">

    <ListView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/lstres">

    </ListView>
</LinearLayout>


5)  ACTIVITY JAVA CODE TO DISPLAY DATA FROM LIST

package com.example.additionapplication;

import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;

import java.util.ArrayList;

public class MainActivity15 extends AppCompatActivity {

   ListView lst;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main15);
        ArrayList<Student> arrstu;
        arrstu = (ArrayList<Student>) getIntent().getSerializableExtra("data");
        lst = findViewById(R.id.lstres);

        ArrayAdapter aa = new ArrayAdapter(getApplicationContext(), android.R.layout.simple_list_item_1,arrstu);
        lst.setAdapter(aa);

        /*  for(Student st:arrstu)
        {
            Toast.makeText(getApplicationContext(),"Rno is "+st.getRno() + " Name is "+st.getSname(),Toast.LENGTH_LONG).show();
        }
      for(Student s:arrstu)
        {
            txtrno.setText(s.getRno());
            txtsname.setText(s.getSname());
        }*/

    }
}