Links & Dependenciesactivity_main.xmlViewPagerAdapter.javaMainActivity.javaAndroidManifest.xml

Library on GitHub with dependency + instructions:

github.com/square/picasso

<?xml version="1.0" encoding="utf-8"?>
<android.support.v4.view.ViewPager 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/view_pager"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="com.codinginflow.picassoimagesliderexample.MainActivity">

</android.support.v4.view.ViewPager>

package com.codinginflow.picassoimagesliderexample;

import android.content.Context;
import android.support.annotation.NonNull;
import android.support.v4.view.PagerAdapter;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;

import com.squareup.picasso.Picasso;


public class ViewPagerAdapter extends PagerAdapter {
    private Context context;
    private String[] imageUrls;

    ViewPagerAdapter(Context context, String[] imageUrls) {
        this.context = context;
        this.imageUrls = imageUrls;
    }

    @Override
    public int getCount() {
        return imageUrls.length;
    }

    @Override
    public boolean isViewFromObject(@NonNull View view, @NonNull Object object) {
        return view == object;
    }

    @NonNull
    @Override
    public Object instantiateItem(@NonNull ViewGroup container, int position) {
        ImageView imageView = new ImageView(context);
        Picasso.get()
                .load(imageUrls[position])
                .fit()
                .centerCrop()
                .into(imageView);
        container.addView(imageView);

        return imageView;
    }

    @Override
    public void destroyItem(@NonNull ViewGroup container, int position, @NonNull Object object) {
        container.removeView((View) object);
    }
}

package com.codinginflow.picassoimagesliderexample;

import android.support.v4.view.ViewPager;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;

public class MainActivity extends AppCompatActivity {
    private String[] imageUrls = new String[]{
            "https://cdn.pixabay.com/photo/2016/11/11/23/34/cat-1817970_960_720.jpg",
            "https://cdn.pixabay.com/photo/2017/12/21/12/26/glowworm-3031704_960_720.jpg",
            "https://cdn.pixabay.com/photo/2017/12/24/09/09/road-3036620_960_720.jpg",
            "https://cdn.pixabay.com/photo/2017/11/07/00/07/fantasy-2925250_960_720.jpg",
            "https://cdn.pixabay.com/photo/2017/10/10/15/28/butterfly-2837589_960_720.jpg"
    };

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        ViewPager viewPager = findViewById(R.id.view_pager);
        ViewPagerAdapter adapter = new ViewPagerAdapter(this, imageUrls);
        viewPager.setAdapter(adapter);
    }
}

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.codinginflow.picassoimagesliderexample">

    <uses-permission android:name="android.permission.INTERNET" />

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>