update solid ex

patterns/pom.xml

@@ -17,6 +17,7 @@
         <module>front-controller</module>
         <module>intercepting-filter</module>
         <module>design-patterns</module>
+        <module>solid</module>
     </modules>
 
     <dependencyManagement>

patterns/principles/solid/src/main/java/com/baeldung/d/Keyboard.java

@@ -1,4 +0,0 @@
-package com.baeldung.d;
-
-public class Keyboard {
-}

patterns/solid/pom.xml

@@ -4,17 +4,14 @@
          xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <groupId>com.baeldung</groupId>
-    <artifactId>solid/artifactId>
+    <artifactId>solid</artifactId>
     <version>1.0-SNAPSHOT</version>
 
-    <dependencies>
-        <!-- https://mvnrepository.com/artifact/junit/junit -->
-        <dependency>
-            <groupId>junit</groupId>
-            <artifactId>junit</artifactId>
-            <version>4.12</version>
-            <scope>test</scope>
-        </dependency>
-    </dependencies>
+ <parent>
+        <groupId>com.baeldung</groupId>
+        <artifactId>patterns</artifactId>
+        <version>1.0.0-SNAPSHOT</version>
+        <relativePath>..</relativePath>
+    </parent>
 
 </project>

patterns/solid/src/main/java/com/baeldung/d/Keyboard.java

@@ -0,0 +1,4 @@
+package com.baeldung.d;
+
+public interface Keyboard {
+}

patterns/solid/src/main/java/com/baeldung/d/StandardKeyboard.java

@@ -0,0 +1,5 @@
+package com.baeldung.d;
+
+public class StandardKeyboard implements Keyboard {
+
+}

patterns/solid/src/main/java/com/baeldung/d/Windows98Machine.java

@@ -2,13 +2,13 @@ package com.baeldung.d;
 
 public class Windows98Machine {
 
-  private final Keyboard keyboard;
+  private final StandardKeyboard keyboard;
   private final Monitor monitor;
 
   public Windows98Machine() {
 
     monitor = new Monitor();
-    keyboard = new Keyboard();
+    keyboard = new StandardKeyboard();
 
   }