Android Multi Select Spinner example Java

1/  Create A New Project  and design the page

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 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:id="@+id/main"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity"
    >

<com.google.android.material.card.MaterialCardView
    android:id="@+id/cardv"
    android:layout_width="match_parent"
    android:layout_height="40dp"
    android:layout_centerInParent="true"
    android:layout_marginLeft="40dp"
    android:layout_marginRight="40dp">

    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent">

        <TextView
            android:id="@+id/tvitem"
            android:layout_width="wrap_content"
            android:layout_height="match_parent"
            android:layout_marginLeft="10dp"
            android:gravity="center"
            android:text="Select the item "
            android:textSize="15sp"
            android:textStyle="bold|italic" />

        <ImageView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignParentRight="true"
            android:src="@drawable/baseline_arrow_drop_down_24" />

    </RelativeLayout>

</com.google.android.material.card.MaterialCardView>
</RelativeLayout>

2/  Java Activity

package com.tutorialb.multispinner;

import android.content.DialogInterface;
import android.os.Bundle;
import android.widget.TextView;
import androidx.activity.EdgeToEdge;
import androidx.appcompat.app.AlertDialog;
import androidx.appcompat.app.AppCompatActivity;
import androidx.core.graphics.Insets;
import androidx.core.view.ViewCompat;
import androidx.core.view.WindowInsetsCompat;
import com.google.android.material.card.MaterialCardView;
import java.util.ArrayList;

public class MainActivity extends AppCompatActivity {
    
    MaterialCardView cardv;
    TextView tvitem;
    ArrayList<Integer> arrayList = new ArrayList<>();
    String[] arrayitem = {"book", "pensil", "pen", "sheet"};
    boolean[] selectitem;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        EdgeToEdge.enable(this);
        setContentView(R.layout.activity_main);
        ViewCompat.setOnApplyWindowInsetsListener(findViewById(R.id.main), (v, insets) -> {
            Insets systemBars = insets.getInsets(WindowInsetsCompat.Type.systemBars());
            v.setPadding(systemBars.left, systemBars.top, systemBars.right, systemBars.bottom);
            return insets;
        });

        cardv = findViewById(R.id.cardv);
        tvitem = findViewById(R.id.tvitem);

        selectitem = new boolean[arrayitem.length];

        cardv.setOnClickListener(v -> {

            ShowAltItem();
        });
    }
    
    public void ShowAltItem() {

        AlertDialog.Builder bilder = new AlertDialog.Builder(this);
        bilder.setTitle("Select Item");
        bilder.setCancelable(false);
        
        bilder.setMultiChoiceItems(arrayitem, selectitem, new DialogInterface.OnMultiChoiceClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int which, boolean isChecked) {
                
                if (isChecked) {

                    arrayList.add(which);
                } else {

                    arrayList.remove(which);
                }
            }
        }).setPositiveButton("OK", new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int which) {

            }
        }).setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int which) {

            }
        }).setNeutralButton("Clear All", new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int which) {
                
            }
        });

        bilder.show();
    }
}

3/ Ran And Output