Merge pull request #4 from ximanta/master

Added eample code of Dependency Inversion Principle

Author: springframeworkguru

src/main/java/guru/springframework/blog/dependencyinversionprinciple/highlevel/ElectricPowerSwitch.java

@@ -0,0 +1,25 @@
+package guru.springframework.blog.dependencyinversionprinciple.highlevel;
+
+
+public class ElectricPowerSwitch implements Switch {
+ public Switchable client;
+ public boolean on;
+ public ElectricPowerSwitch(Switchable client) {
+ this.client = client;
+ this.on = false;
+ }
+ public boolean isOn() {
+ return this.on;
+ }
+ public void press(){
+ boolean checkOn = isOn();
+ if (checkOn) {
+ client.turnOff();
+ this.on = false;
+ } else {
+ client.turnOn();
+ this.on = true;
+ }
+
+ }
+}

src/main/java/guru/springframework/blog/dependencyinversionprinciple/highlevel/Switch.java

@@ -0,0 +1,6 @@
+package guru.springframework.blog.dependencyinversionprinciple.highlevel;
+
+public interface Switch {
+ boolean isOn();
+ void press();
+}

src/main/java/guru/springframework/blog/dependencyinversionprinciple/highlevel/Switchable.java

@@ -0,0 +1,6 @@
+package guru.springframework.blog.dependencyinversionprinciple.highlevel;
+
+public interface Switchable {
+ void turnOn();
+ void turnOff();
+}

src/main/java/guru/springframework/blog/dependencyinversionprinciple/lowlevel/Fan.java

@@ -0,0 +1,15 @@
+package guru.springframework.blog.dependencyinversionprinciple.lowlevel;
+
+import guru.springframework.blog.dependencyinversionprinciple.highlevel.Switchable;
+
+public class Fan implements Switchable {
+ @Override
+ public void turnOn() {
+ System.out.println("Fan: Fan turned on...");
+ }
+
+ @Override
+ public void turnOff() {
+ System.out.println("Fan: Fan turned off...");
+ }
+}

src/main/java/guru/springframework/blog/dependencyinversionprinciple/lowlevel/LightBulb.java

@@ -0,0 +1,15 @@
+package guru.springframework.blog.dependencyinversionprinciple.lowlevel;
+
+import guru.springframework.blog.dependencyinversionprinciple.highlevel.Switchable;
+
+public class LightBulb implements Switchable {
+ @Override
+ public void turnOn() {
+ System.out.println("LightBulb: Bulb turned on...");
+ }
+
+ @Override
+ public void turnOff() {
+ System.out.println("LightBulb: Bulb turned off...");
+ }
+}

src/test/java/guru/springframework/blog/dependencyinversionprinciple/highlevel/ElectricPowerSwitchTest.java

@@ -0,0 +1,21 @@
+package guru.springframework.blog.dependencyinversionprinciple.highlevel;
+
+import guru.springframework.blog.dependencyinversionprinciple.lowlevel.Fan;
+import guru.springframework.blog.dependencyinversionprinciple.lowlevel.LightBulb;
+import org.junit.Test;
+
+public class ElectricPowerSwitchTest {
+
+ @Test
+ public void testPress() throws Exception {
+ Switchable switchableBulb=new LightBulb();
+ Switch bulbPowerSwitch=new ElectricPowerSwitch(switchableBulb);
+ bulbPowerSwitch.press();
+ bulbPowerSwitch.press();
+
+ Switchable switchableFan=new Fan();
+ Switch fanPowerSwitch=new ElectricPowerSwitch(switchableFan);
+ fanPowerSwitch.press();
+ fanPowerSwitch.press();
+ }
+}