Adding Interface Segregation and Dependency Inversion principles clas…

…ses examples

README.md

@@ -5,4 +5,5 @@ This repository will be the typical one to collect those fundamentals of program
   - TDD
   - SOLID principles
   - Clean Code 
+  - Patterns
   - ...

solid/src/main/java/com/jazzinjars/solid/dependency/BackEndDeveloper.java

@@ -0,0 +1,13 @@
+package com.jazzinjars.solid.dependency;
+
+public class BackEndDeveloper implements Developer {
+
+	@Override
+	public void develop() {
+		writeJava();
+	}
+
+	private void writeJava() {
+
+	}
+}

solid/src/main/java/com/jazzinjars/solid/dependency/Developer.java

@@ -0,0 +1,6 @@
+package com.jazzinjars.solid.dependency;
+
+public interface Developer {
+
+	void develop();
+}

solid/src/main/java/com/jazzinjars/solid/dependency/FrontEndDeveloper.java

@@ -0,0 +1,13 @@
+package com.jazzinjars.solid.dependency;
+
+public class FrontEndDeveloper implements Developer {
+
+	@Override
+	public void develop() {
+		writeJavaScript();
+	}
+
+	private void writeJavaScript() {
+
+	}
+}

solid/src/main/java/com/jazzinjars/solid/dependency/Project.java

@@ -0,0 +1,31 @@
+package com.jazzinjars.solid.dependency;
+
+import java.util.List;
+
+public class Project {
+
+	private List<Developer> developers;
+
+	// So as we can see the Project class is a high level module and it depends on low level modules
+	// such as BackEndDeveloper and FrontEndDeveloper. We are actually violating the first part of
+	// the dependency inversion principle.
+	// ------>
+	private BackEndDeveloper backEndDeveloper = new BackEndDeveloper();
+	private FrontEndDeveloper frontEndDeveloper = new FrontEndDeveloper();
+
+	public void implementNoPrinciple() {
+//		backEndDeveloper.writeJava();
+//		frontEndDeveloper.writeJavaScript();
+	}
+	// ------>
+
+	public Project(List<Developer> developers) {
+		this.developers = developers;
+	}
+
+	public void implement() {
+		developers.forEach(d -> d.develop());
+	}
+}
+
+

solid/src/main/java/com/jazzinjars/solid/interfacesegregation/Athlete.java

@@ -0,0 +1,12 @@
+package com.jazzinjars.solid.interfacesegregation;
+
+public interface Athlete {
+
+	void compete();
+
+//	void swim();
+
+//	void highJump();
+
+//	void longJump();
+}

solid/src/main/java/com/jazzinjars/solid/interfacesegregation/JohnSmith.java

@@ -0,0 +1,14 @@
+package com.jazzinjars.solid.interfacesegregation;
+
+public class JohnSmith implements SwimmingAthlete {
+
+	@Override
+	public void compete() {
+		System.out.println("John Smith started competing");
+	}
+
+	@Override
+	public void swim() {
+		System.out.println("John Smith started swimming");
+	}
+}

solid/src/main/java/com/jazzinjars/solid/interfacesegregation/JumpingAthlete.java

@@ -0,0 +1,8 @@
+package com.jazzinjars.solid.interfacesegregation;
+
+public interface JumpingAthlete extends Athlete {
+
+	void highJump();
+
+	void longJump();
+}

solid/src/main/java/com/jazzinjars/solid/interfacesegregation/SwimmingAthlete.java

@@ -0,0 +1,6 @@
+package com.jazzinjars.solid.interfacesegregation;
+
+public interface SwimmingAthlete extends Athlete {
+
+	void swim();
+}