issue 508 - using copy constructor to implement prototype.

As per http://www.artima.com/intv/bloch13.html, clone method in java is
broken or confusing. So staying away from clone method.

prototype/src/main/java/com/iluwatar/prototype/App.java

@@ -52,7 +52,7 @@ public class App {
     Warlord warlord;
     Beast beast;
 
-    factory = new HeroFactoryImpl(new ElfMage(), new ElfWarlord(), new ElfBeast());
+    factory = new HeroFactoryImpl(new ElfMage("cooking"), new ElfWarlord("cleaning"), new ElfBeast("protecting"));
     mage = factory.createMage();
     warlord = factory.createWarlord();
     beast = factory.createBeast();
@@ -60,7 +60,7 @@ public class App {
     LOGGER.info(warlord.toString());
     LOGGER.info(beast.toString());
 
-    factory = new HeroFactoryImpl(new OrcMage(), new OrcWarlord(), new OrcBeast());
+    factory = new HeroFactoryImpl(new OrcMage("axe"), new OrcWarlord("sword"), new OrcBeast("laser"));
     mage = factory.createMage();
     warlord = factory.createWarlord();
     beast = factory.createBeast();

prototype/src/main/java/com/iluwatar/prototype/Beast.java

@@ -30,6 +30,6 @@ package com.iluwatar.prototype;
 public abstract class Beast extends Prototype {
 
   @Override
-  public abstract Beast clone() throws CloneNotSupportedException;
+  public abstract Beast copy() throws CloneNotSupportedException;
 
 }

prototype/src/main/java/com/iluwatar/prototype/ElfBeast.java

@@ -29,16 +29,24 @@ package com.iluwatar.prototype;
  */
 public class ElfBeast extends Beast {
   
-  public ElfBeast() {}
+  private String helpType;
+
+  public ElfBeast(String helpType) {
+    this.helpType = helpType;
+  }
+
+  public ElfBeast(ElfBeast elfBeast) {
+    this.helpType = elfBeast.helpType;
+  }
 
   @Override
-  public Beast clone() throws CloneNotSupportedException {
+  public Beast copy() throws CloneNotSupportedException {
-    return new ElfBeast();
+    return new ElfBeast(this);
   }
 
   @Override
   public String toString() {
-    return "Elven eagle";
+    return "Elven eagle helps in " + helpType;
   }
 
 }

prototype/src/main/java/com/iluwatar/prototype/ElfMage.java

@@ -29,16 +29,25 @@ package com.iluwatar.prototype;
  */
 public class ElfMage extends Mage {
 
-  public ElfMage() {}
+  
+  private String helpType;
+  
+  public ElfMage(String helpType) {
+    this.helpType = helpType;
+  }
+
+  public ElfMage(ElfMage elfMage) {
+    this.helpType = elfMage.helpType;
+  }
 
   @Override
-  public Mage clone() throws CloneNotSupportedException {
+  public ElfMage copy() throws CloneNotSupportedException {
-    return new ElfMage();
+    return new ElfMage(this);
   }
 
   @Override
   public String toString() {
-    return "Elven mage";
+    return "Elven mage helps in " + helpType;
   }
 
 }

prototype/src/main/java/com/iluwatar/prototype/ElfWarlord.java

@@ -29,16 +29,24 @@ package com.iluwatar.prototype;
  */
 public class ElfWarlord extends Warlord {
 
-  public ElfWarlord() {}
+  private String helpType;
+  
+  public ElfWarlord(String helpType) {
+    this.helpType = helpType;
+  }
+
+  public ElfWarlord(ElfWarlord elfWarlord) {
+    this.helpType = elfWarlord.helpType;
+  }
 
   @Override
-  public Warlord clone() throws CloneNotSupportedException {
+  public ElfWarlord copy() throws CloneNotSupportedException {
-    return new ElfWarlord();
+    return new ElfWarlord(this);
   }
 
   @Override
   public String toString() {
-    return "Elven warlord";
+    return "Elven warlord helps in " + helpType;
   }
 
 }

prototype/src/main/java/com/iluwatar/prototype/HeroFactoryImpl.java

@@ -47,7 +47,7 @@ public class HeroFactoryImpl implements HeroFactory {
    */
   public Mage createMage() {
     try {
-      return mage.clone();
+      return mage.copy();
     } catch (CloneNotSupportedException e) {
       return null;
     }
@@ -58,7 +58,7 @@ public class HeroFactoryImpl implements HeroFactory {
    */
   public Warlord createWarlord() {
     try {
-      return warlord.clone();
+      return warlord.copy();
     } catch (CloneNotSupportedException e) {
       return null;
     }
@@ -69,7 +69,7 @@ public class HeroFactoryImpl implements HeroFactory {
    */
   public Beast createBeast() {
     try {
-      return beast.clone();
+      return beast.copy();
     } catch (CloneNotSupportedException e) {
       return null;
     }

prototype/src/main/java/com/iluwatar/prototype/Mage.java

@@ -30,6 +30,6 @@ package com.iluwatar.prototype;
 public abstract class Mage extends Prototype {
 
   @Override
-  public abstract Mage clone() throws CloneNotSupportedException;
+  public abstract Mage copy() throws CloneNotSupportedException;
 
 }

prototype/src/main/java/com/iluwatar/prototype/OrcBeast.java

@@ -29,16 +29,25 @@ package com.iluwatar.prototype;
  */
 public class OrcBeast extends Beast {
   
-  public OrcBeast() {}
+  private String weapon;
+
+  public OrcBeast(String weapon) {
+    this.weapon = weapon;
+  }
+  
+  public OrcBeast(OrcBeast orcBeast) {
+    this.weapon = orcBeast.weapon;
+  }
 
   @Override
-  public Beast clone() throws CloneNotSupportedException {
+  public Beast copy() throws CloneNotSupportedException {
-    return new OrcBeast();
+    return new OrcBeast(this);
   }
 
   @Override
   public String toString() {
-    return "Orcish wolf";
+    return "Orcish wolf attacks with " + weapon;
   }
   
+
 }

prototype/src/main/java/com/iluwatar/prototype/OrcMage.java

@@ -29,16 +29,24 @@ package com.iluwatar.prototype;
  */
 public class OrcMage extends Mage {
 
-  public OrcMage() {}
+  private String weapon;
+
+  public OrcMage(String weapon) {
+    this.weapon = weapon;
+  }
+  
+  public OrcMage(OrcMage orcMage) {
+    this.weapon = orcMage.weapon;
+  }
 
   @Override
-  public Mage clone() throws CloneNotSupportedException {
+  public OrcMage copy() throws CloneNotSupportedException {
-    return new OrcMage();
+    return new OrcMage(this);
   }
 
   @Override
   public String toString() {
-    return "Orcish mage";
+    return "Orcish mage attacks with " + weapon;
   }
 
 }

prototype/src/main/java/com/iluwatar/prototype/OrcWarlord.java

@@ -29,16 +29,24 @@ package com.iluwatar.prototype;
  */
 public class OrcWarlord extends Warlord {
 
-  public OrcWarlord() {}
+  private String weapon;
+
+  public OrcWarlord(String weapon) {
+    this.weapon = weapon;
+  }
+  
+  public OrcWarlord(OrcWarlord orcWarlord) {
+    this.weapon = orcWarlord.weapon;
+  }
 
   @Override
-  public Warlord clone() throws CloneNotSupportedException {
+  public OrcWarlord copy() throws CloneNotSupportedException {
-    return new OrcWarlord();
+    return new OrcWarlord(this);
   }
 
   @Override
   public String toString() {
-    return "Orcish warlord";
+    return "Orcish warlord attacks with " + weapon;
   }
 
 }

prototype/src/main/java/com/iluwatar/prototype/Prototype.java

@@ -29,7 +29,6 @@ package com.iluwatar.prototype;
  */
 public abstract class Prototype implements Cloneable {
 
-  @Override
+  public abstract Object copy() throws CloneNotSupportedException;
-  public abstract Object clone() throws CloneNotSupportedException;
 
 }

prototype/src/main/java/com/iluwatar/prototype/Warlord.java

@@ -30,6 +30,6 @@ package com.iluwatar.prototype;
 public abstract class Warlord extends Prototype {
 
   @Override
-  public abstract Warlord clone() throws CloneNotSupportedException;
+  public abstract Warlord copy() throws CloneNotSupportedException;
 
 }

prototype/src/test/java/com/iluwatar/prototype/HeroFactoryImplTest.java

@@ -43,18 +43,18 @@ public class HeroFactoryImplTest {
     final Warlord warlord = mock(Warlord.class);
     final Beast beast = mock(Beast.class);
 
-    when(mage.clone()).thenThrow(CloneNotSupportedException.class);
+    when(mage.copy()).thenThrow(CloneNotSupportedException.class);
-    when(warlord.clone()).thenThrow(CloneNotSupportedException.class);
+    when(warlord.copy()).thenThrow(CloneNotSupportedException.class);
-    when(beast.clone()).thenThrow(CloneNotSupportedException.class);
+    when(beast.copy()).thenThrow(CloneNotSupportedException.class);
 
     final HeroFactoryImpl factory = new HeroFactoryImpl(mage, warlord, beast);
     assertNull(factory.createMage());
     assertNull(factory.createWarlord());
     assertNull(factory.createBeast());
 
-    verify(mage).clone();
+    verify(mage).copy();
-    verify(warlord).clone();
+    verify(warlord).copy();
-    verify(beast).clone();
+    verify(beast).copy();
     verifyNoMoreInteractions(mage, warlord, beast);
   }
 

prototype/src/test/java/com/iluwatar/prototype/PrototypeTest.java

@@ -41,12 +41,12 @@ import static org.junit.jupiter.api.Assertions.assertSame;
 public class PrototypeTest<P extends Prototype> {
   static Collection<Object[]> dataProvider() {
     return Arrays.asList(
-            new Object[]{new OrcBeast(), "Orcish wolf"},
+            new Object[]{new OrcBeast("axe"), "Orcish wolf attacks with axe"},
-            new Object[]{new OrcMage(), "Orcish mage"},
+            new Object[]{new OrcMage("sword"), "Orcish mage attacks with sword"},
-            new Object[]{new OrcWarlord(), "Orcish warlord"},
+            new Object[]{new OrcWarlord("laser"), "Orcish warlord attacks with laser"},
-            new Object[]{new ElfBeast(), "Elven eagle"},
+            new Object[]{new ElfBeast("cooking"), "Elven eagle helps in cooking"},
-            new Object[]{new ElfMage(), "Elven mage"},
+            new Object[]{new ElfMage("cleaning"), "Elven mage helps in cleaning"},
-            new Object[]{new ElfWarlord(), "Elven warlord"}
+            new Object[]{new ElfWarlord("protecting"), "Elven warlord helps in protecting"}
     );
   }
 
@@ -55,7 +55,7 @@ public class PrototypeTest<P extends Prototype> {
   public void testPrototype(P testedPrototype, String expectedToString) throws Exception {
     assertEquals(expectedToString, testedPrototype.toString());
 
-    final Object clone = testedPrototype.clone();
+    final Object clone = testedPrototype.copy();
     assertNotNull(clone);
     assertNotSame(clone, testedPrototype);
     assertSame(testedPrototype.getClass(), clone.getClass());