fix: Interfaces and Abstract classes

Interfaces/.gitignore

@@ -0,0 +1,29 @@
+### IntelliJ IDEA ###
+out/
+!**/src/main/**/out/
+!**/src/test/**/out/
+
+### Eclipse ###
+.apt_generated
+.classpath
+.factorypath
+.project
+.settings
+.springBeans
+.sts4-cache
+bin/
+!**/src/main/**/bin/
+!**/src/test/**/bin/
+
+### NetBeans ###
+/nbproject/private/
+/nbbuild/
+/dist/
+/nbdist/
+/.nb-gradle/
+
+### VS Code ###
+.vscode/
+
+### Mac OS ###
+.DS_Store

Interfaces/.idea/.gitignore

@@ -0,0 +1,3 @@
+# Default ignored files
+/shelf/
+/workspace.xml

Interfaces/.idea/codeStyles/Project.xml

@@ -0,0 +1,7 @@
+<component name="ProjectCodeStyleConfiguration">
+  <code_scheme name="Project" version="173">
+    <ScalaCodeStyleSettings>
+      <option name="MULTILINE_STRING_CLOSING_QUOTES_ON_NEW_LINE" value="true" />
+    </ScalaCodeStyleSettings>
+  </code_scheme>
+</component>

Interfaces/.idea/codeStyles/codeStyleConfig.xml

@@ -0,0 +1,5 @@
+<component name="ProjectCodeStyleConfiguration">
+  <state>
+    <option name="PREFERRED_PROJECT_CODE_STYLE" value="Default" />
+  </state>
+</component>

Interfaces/.idea/git_toolbox_blame.xml

@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="GitToolBoxBlameSettings">
+    <option name="version" value="2" />
+  </component>
+</project>

Interfaces/.idea/misc.xml

@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="ProjectRootManager" version="2" languageLevel="JDK_17" default="true" project-jdk-name="openjdk-23" project-jdk-type="JavaSDK">
+    <output url="file://$PROJECT_DIR$/out" />
+  </component>
+</project>

Interfaces/.idea/modules.xml

@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="ProjectModuleManager">
+    <modules>
+      <module fileurl="file://$PROJECT_DIR$/Interfaces.iml" filepath="$PROJECT_DIR$/Interfaces.iml" />
+    </modules>
+  </component>
+</project>

Interfaces/.idea/vcs.xml

@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="VcsDirectoryMappings">
+    <mapping directory="$PROJECT_DIR$/.." vcs="Git" />
+  </component>
+</project>

Interfaces/Interfaces.iml

@@ -0,0 +1,11 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<module type="JAVA_MODULE" version="4">
+  <component name="NewModuleRootManager" inherit-compiler-output="true">
+    <exclude-output />
+    <content url="file://$MODULE_DIR$">
+      <sourceFolder url="file://$MODULE_DIR$/src" isTestSource="false" />
+    </content>
+    <orderEntry type="inheritedJdk" />
+    <orderEntry type="sourceFolder" forTests="false" />
+  </component>
+</module>

Interfaces/src/CountingSender.java

@@ -0,0 +1,14 @@
+public abstract class CountingSender {
+    private String prefix;
+    private int counter;
+
+    public CountingSender(String prefix){
+        this.prefix = prefix;
+    }
+    public void Greet(String message){
+        this.counter ++;
+        this.write("%d: %s,%s".formatted(this.counter, this.prefix, message));
+    }
+
+    abstract void write(String message);
+}

Interfaces/src/MessageSender.java

@@ -0,0 +1,11 @@
+public class MessageSender extends CountingSender {
+
+    public MessageSender(String prefix) {
+        super(prefix);
+    }
+
+    @Override
+    void write(String message) {
+        System.out.println("- " + message);
+    }
+}

Interfaces/src/Sender.java

@@ -0,0 +1,6 @@
+public interface Sender {
+    void send(String message);
+    default void Greet(String prefix, String message){
+        send(prefix + " ---- " + message);
+    }
+}

Interfaces/src/TextSender.java

@@ -0,0 +1,16 @@
+public class TextSender implements Sender{
+    @Override
+    public void send(String message) {
+        System.out.println(message);
+    }
+
+    public static void main(String[] args) {
+        var txtSender = new TextSender();
+        txtSender.Greet("Hello", "Naruto");
+        System.out.println("---");
+        var msgSender = new MessageSender("Hello");
+        msgSender.Greet(" Sasuke");
+        msgSender.Greet(" Ichigo");
+
+    }
+}