BAEL-5417 - implements vs extends (#12011)

core-java-modules/core-java-lang-4/src/main/java/com/baeldung/implementsvsextends/Main.java

@@ -0,0 +1,60 @@
+package com.baeldung.implementsvsextends;
+
+import com.baeldung.implementsvsextends.media.model.AudioMedia;
+import com.baeldung.implementsvsextends.media.model.Media;
+import com.baeldung.implementsvsextends.media.model.VideoMedia;
+import com.baeldung.implementsvsextends.media.player.impl.AudioMediaPlayer;
+import com.baeldung.implementsvsextends.media.player.impl.CustomMediaPlayer;
+import com.baeldung.implementsvsextends.media.player.impl.MultiMediaPlayer;
+import com.baeldung.implementsvsextends.media.player.impl.VideoMediaPlayer;
+
+public class Main {
+
+    public static void main(String[] args) {
+
+        Media media = new Media();
+        media.setId(001);
+        media.setTitle("Media1");
+        media.setArtist("Artist001");
+
+        AudioMedia audioMedia = new AudioMedia();
+        audioMedia.setId(101);
+        audioMedia.setTitle("Audio1");
+        audioMedia.setArtist("Artist101");
+        audioMedia.setBitrate(3500);
+        audioMedia.setFrequency("256kbps");
+
+        VideoMedia videoMedia = new VideoMedia();
+        videoMedia.setId(201);
+        videoMedia.setTitle("Video1");
+        videoMedia.setArtist("Artist201");
+        videoMedia.setResolution("1024x768");
+        videoMedia.setAspectRatio("16:9");
+
+        System.out.println(media);
+        System.out.println(audioMedia);
+        System.out.println(videoMedia);
+
+        AudioMediaPlayer audioMediaPlayer = new AudioMediaPlayer();
+        audioMediaPlayer.play();
+        audioMediaPlayer.pause();
+
+        VideoMediaPlayer videoMediaPlayer = new VideoMediaPlayer();
+        videoMediaPlayer.play();
+        videoMediaPlayer.pause();
+
+        MultiMediaPlayer multiMediaPlayer = new MultiMediaPlayer();
+        multiMediaPlayer.play();
+        multiMediaPlayer.pause();
+        multiMediaPlayer.seek();
+        multiMediaPlayer.fastForward();
+
+        CustomMediaPlayer customMediaPlayer = new CustomMediaPlayer();
+        customMediaPlayer.play();
+        customMediaPlayer.pause();
+        customMediaPlayer.setId(301);
+        customMediaPlayer.setTitle("Custom1");
+        customMediaPlayer.setArtist("Artist301");
+        System.out.println(customMediaPlayer);
+    }
+}

core-java-modules/core-java-lang-4/src/main/java/com/baeldung/implementsvsextends/media/model/AudioMedia.java

@@ -0,0 +1,41 @@
+package com.baeldung.implementsvsextends.media.model;
+
+public class AudioMedia extends Media {
+
+    private int bitrate;
+
+    private String frequency;
+
+    @Override
+    public void printTitle() {
+        System.out.println("AudioMedia Title");
+    }
+
+    public int getBitrate() {
+        return bitrate;
+    }
+
+    public void setBitrate(int bitrate) {
+        this.bitrate = bitrate;
+    }
+
+    public String getFrequency() {
+        return frequency;
+    }
+
+    public void setFrequency(String frequency) {
+        this.frequency = frequency;
+    }
+
+
+    @Override
+    public String toString() {
+        return "AudioMedia{" +
+                "id=" + this.getId() +
+                ", title='" + this.getTitle() + '\'' +
+                ", artist='" + this.getArtist() + '\'' +
+                ", bitrate=" + bitrate +
+                ", frequency='" + frequency + '\'' +
+                "} ";
+    }
+}

core-java-modules/core-java-lang-4/src/main/java/com/baeldung/implementsvsextends/media/model/Media.java

@@ -0,0 +1,47 @@
+package com.baeldung.implementsvsextends.media.model;
+
+public class Media {
+
+    private int id;
+
+    private String title;
+
+    private String artist;
+
+    public void printTitle() {
+        System.out.println("Media Title");
+    }
+
+    public int getId() {
+        return id;
+    }
+
+    public void setId(int id) {
+        this.id = id;
+    }
+
+    public String getTitle() {
+        return title;
+    }
+
+    public void setTitle(String title) {
+        this.title = title;
+    }
+
+    public String getArtist() {
+        return artist;
+    }
+
+    public void setArtist(String artist) {
+        this.artist = artist;
+    }
+
+    @Override
+    public String toString() {
+        return "Media{" +
+                "id=" + id +
+                ", title='" + title + '\'' +
+                ", artist='" + artist + '\'' +
+                '}';
+    }
+}

core-java-modules/core-java-lang-4/src/main/java/com/baeldung/implementsvsextends/media/model/VideoMedia.java

@@ -0,0 +1,35 @@
+package com.baeldung.implementsvsextends.media.model;
+
+public class VideoMedia extends Media {
+
+    private String resolution;
+
+    private String aspectRatio;
+
+    public String getResolution() {
+        return resolution;
+    }
+
+    public void setResolution(String resolution) {
+        this.resolution = resolution;
+    }
+
+    public String getAspectRatio() {
+        return aspectRatio;
+    }
+
+    public void setAspectRatio(String aspectRatio) {
+        this.aspectRatio = aspectRatio;
+    }
+
+    @Override
+    public String toString() {
+        return "VideoMedia{" +
+                "id=" + this.getId() +
+                ", title='" + this.getTitle() + '\'' +
+                ", artist='" + this.getArtist() + '\'' +
+                "resolution='" + resolution + '\'' +
+                ", aspectRatio='" + aspectRatio + '\'' +
+                "} ";
+    }
+}

core-java-modules/core-java-lang-4/src/main/java/com/baeldung/implementsvsextends/media/player/AdvancedPlayerOptions.java

@@ -0,0 +1,8 @@
+package com.baeldung.implementsvsextends.media.player;
+
+public interface AdvancedPlayerOptions {
+
+    void seek();
+
+    void fastForward();
+}

core-java-modules/core-java-lang-4/src/main/java/com/baeldung/implementsvsextends/media/player/MediaPlayer.java

@@ -0,0 +1,8 @@
+package com.baeldung.implementsvsextends.media.player;
+
+public interface MediaPlayer {
+
+    void play();
+
+    void pause();
+}

core-java-modules/core-java-lang-4/src/main/java/com/baeldung/implementsvsextends/media/player/impl/AudioMediaPlayer.java

@@ -0,0 +1,16 @@
+package com.baeldung.implementsvsextends.media.player.impl;
+
+import com.baeldung.implementsvsextends.media.player.MediaPlayer;
+
+public class AudioMediaPlayer implements MediaPlayer {
+
+    @Override
+    public void play() {
+        System.out.println("AudioMediaPlayer is Playing");
+    }
+
+    @Override
+    public void pause() {
+        System.out.println("AudioMediaPlayer is Paused");
+    }
+}

core-java-modules/core-java-lang-4/src/main/java/com/baeldung/implementsvsextends/media/player/impl/CustomMediaPlayer.java

@@ -0,0 +1,17 @@
+package com.baeldung.implementsvsextends.media.player.impl;
+
+import com.baeldung.implementsvsextends.media.model.Media;
+import com.baeldung.implementsvsextends.media.player.MediaPlayer;
+
+public class CustomMediaPlayer extends Media implements MediaPlayer {
+
+    @Override
+    public void play() {
+        System.out.println("CustomMediaPlayer is Playing");
+    }
+
+    @Override
+    public void pause() {
+        System.out.println("CustomMediaPlayer is Paused");
+    }
+}

core-java-modules/core-java-lang-4/src/main/java/com/baeldung/implementsvsextends/media/player/impl/MultiMediaPlayer.java

@@ -0,0 +1,27 @@
+package com.baeldung.implementsvsextends.media.player.impl;
+
+import com.baeldung.implementsvsextends.media.player.AdvancedPlayerOptions;
+import com.baeldung.implementsvsextends.media.player.MediaPlayer;
+
+public class MultiMediaPlayer implements MediaPlayer, AdvancedPlayerOptions {
+
+    @Override
+    public void play() {
+        System.out.println("MultiMediaPlayer is Playing");
+    }
+
+    @Override
+    public void pause() {
+        System.out.println("MultiMediaPlayer is Paused");
+    }
+
+    @Override
+    public void seek() {
+        System.out.println("MultiMediaPlayer is being seeked");
+    }
+
+    @Override
+    public void fastForward() {
+        System.out.println("MultiMediaPlayer is being fast forwarded");
+    }
+}

core-java-modules/core-java-lang-4/src/main/java/com/baeldung/implementsvsextends/media/player/impl/VideoMediaPlayer.java

@@ -0,0 +1,16 @@
+package com.baeldung.implementsvsextends.media.player.impl;
+
+import com.baeldung.implementsvsextends.media.player.MediaPlayer;
+
+public class VideoMediaPlayer implements MediaPlayer {
+
+    @Override
+    public void play() {
+        System.out.println("VideoMediaPlayer is Playing");
+    }
+
+    @Override
+    public void pause() {
+        System.out.println("VideoMediaPlayer is Paused");
+    }
+}

core-java-modules/core-java-lang-4/src/test/java/com/baeldung/implementsvsextends/model/AudioMediaUnitTest.java

@@ -0,0 +1,14 @@
+package com.baeldung.implementsvsextends.media.model;
+
+import org.hamcrest.CoreMatchers;
+import org.junit.Assert;
+import org.junit.Test;
+
+public class AudioMediaUnitTest {
+
+    @Test
+    public void givenAudioMediaInstance_whenCheckedType_thenIsInstanceOfMedia() {
+        AudioMedia audioMedia = new AudioMedia();
+        Assert.assertThat(audioMedia, CoreMatchers.<AudioMedia>instanceOf(Media.class));
+    }
+}

core-java-modules/core-java-lang-4/src/test/java/com/baeldung/implementsvsextends/model/VideoMediaUnitTest.java

@@ -0,0 +1,14 @@
+package com.baeldung.implementsvsextends.media.model;
+
+import org.hamcrest.CoreMatchers;
+import org.junit.Assert;
+import org.junit.Test;
+
+public class VideoMediaUnitTest {
+
+    @Test
+    public void givenVideoMediaInstance_whenCheckedType_thenIsInstanceOfMedia() {
+        VideoMedia videoMedia = new VideoMedia();
+        Assert.assertThat(videoMedia, CoreMatchers.<VideoMedia>instanceOf(Media.class));
+    }
+}

core-java-modules/core-java-lang-4/src/test/java/com/baeldung/implementsvsextends/player/impl/AudioMediaPlayerUnitTest.java

@@ -0,0 +1,41 @@
+package com.baeldung.implementsvsextends.media.player.impl;
+
+import org.junit.Assert;
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+import java.io.ByteArrayOutputStream;
+import java.io.PrintStream;
+
+public class AudioMediaPlayerUnitTest {
+
+    private final PrintStream standardOut = System.out;
+    private final ByteArrayOutputStream outputStreamCaptor = new ByteArrayOutputStream();
+
+    @BeforeEach
+    public void setUp() {
+        System.setOut(new PrintStream(outputStreamCaptor));
+    }
+
+    @AfterEach
+    public void tearDown() {
+        System.setOut(standardOut);
+    }
+
+    @Test
+    public void givenAudioMediaPlayer_whenPlay_thenPrintsPlayingString() {
+        AudioMediaPlayer audioMediaPlayer = new AudioMediaPlayer();
+        audioMediaPlayer.play();
+        Assert.assertEquals("AudioMediaPlayer is Playing", outputStreamCaptor.toString()
+                .trim());
+    }
+
+    @Test
+    public void givenAudioMediaPlayer_whenPause_thenPrintsPausedString() {
+        AudioMediaPlayer audioMediaPlayer = new AudioMediaPlayer();
+        audioMediaPlayer.pause();
+        Assert.assertEquals("AudioMediaPlayer is Paused", outputStreamCaptor.toString()
+                .trim());
+    }
+}

core-java-modules/core-java-lang-4/src/test/java/com/baeldung/implementsvsextends/player/impl/MultiMediaPlayerUnitTest.java

@@ -0,0 +1,58 @@
+package com.baeldung.implementsvsextends.media.player.impl;
+
+import org.junit.Assert;
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+import java.io.ByteArrayOutputStream;
+import java.io.PrintStream;
+
+public class MultiMediaPlayerUnitTest {
+
+    private final PrintStream standardOut = System.out;
+    private final ByteArrayOutputStream outputStreamCaptor = new ByteArrayOutputStream();
+
+    @BeforeEach
+    public void setUp() {
+        System.setOut(new PrintStream(outputStreamCaptor));
+    }
+
+    @AfterEach
+    public void tearDown() {
+        System.setOut(standardOut);
+    }
+
+    @Test
+    public void givenMultiMediaPlayer_whenPlay_thenPrintsPlayingString() {
+        MultiMediaPlayer multiMediaPlayer = new MultiMediaPlayer();
+        multiMediaPlayer.play();
+        Assert.assertEquals("MultiMediaPlayer is Playing", outputStreamCaptor.toString()
+                .trim());
+    }
+
+    @Test
+    public void givenMultiMediaPlayer_whenPause_thenPrintsPausedString() {
+        MultiMediaPlayer multiMediaPlayer = new MultiMediaPlayer();
+        multiMediaPlayer.pause();
+        Assert.assertEquals("MultiMediaPlayer is Paused", outputStreamCaptor.toString()
+                .trim());
+    }
+
+    @Test
+    public void givenMultiMediaPlayer_whenSeek_thenPrintsPausedString() {
+        MultiMediaPlayer multiMediaPlayer = new MultiMediaPlayer();
+        multiMediaPlayer.seek();
+        Assert.assertEquals("MultiMediaPlayer is being seeked", outputStreamCaptor.toString()
+                .trim());
+    }
+
+    @Test
+    public void givenMultiMediaPlayer_whenFastForward_thenPrintsPausedString() {
+        MultiMediaPlayer multiMediaPlayer = new MultiMediaPlayer();
+        multiMediaPlayer.fastForward();
+        Assert.assertEquals("MultiMediaPlayer is being fast forwarded",
+                outputStreamCaptor.toString()
+                .trim());
+    }
+}

core-java-modules/core-java-lang-4/src/test/java/com/baeldung/implementsvsextends/player/impl/VideoMediaPlayerUnitTest.java

@@ -0,0 +1,41 @@
+package com.baeldung.implementsvsextends.media.player.impl;
+
+import org.junit.Assert;
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+import java.io.ByteArrayOutputStream;
+import java.io.PrintStream;
+
+public class VideoMediaPlayerUnitTest {
+
+    private final PrintStream standardOut = System.out;
+    private final ByteArrayOutputStream outputStreamCaptor = new ByteArrayOutputStream();
+
+    @BeforeEach
+    public void setUp() {
+        System.setOut(new PrintStream(outputStreamCaptor));
+    }
+
+    @AfterEach
+    public void tearDown() {
+        System.setOut(standardOut);
+    }
+
+    @Test
+    public void givenVideoMediaPlayer_whenPlay_thenPrintsPlayingString() {
+        VideoMediaPlayer videoMediaPlayer = new VideoMediaPlayer();
+        videoMediaPlayer.play();
+        Assert.assertEquals("VideoMediaPlayer is Playing", outputStreamCaptor.toString()
+                .trim());
+    }
+
+    @Test
+    public void givenVideoMediaPlayer_whenPause_thenPrintsPausedString() {
+        VideoMediaPlayer videoMediaPlayer = new VideoMediaPlayer();
+        videoMediaPlayer.pause();
+        Assert.assertEquals("VideoMediaPlayer is Paused", outputStreamCaptor.toString()
+                .trim());
+    }
+}