Group C
Q.no 8
Step 1
|
1 2 3 |
public interface Shape { void draw(); } |
Create an interface.
Shape.java
Step 2
Create concrete classes implementing the same interface.
Rectangle.java
|
1 2 3 4 5 6 |
<span class="kwd">public</span> <span class="kwd">class</span> <span class="typ">Rectangle</span> <span class="kwd">implements</span> <span class="typ">Shape</span> <span class="pun">{</span> <span class="lit">@Override</span> <span class="kwd">public</span> <span class="kwd">void</span><span class="pln"> draw</span><span class="pun">()</span> <span class="pun">{</span> <span class="typ">System</span><span class="pun">.</span><span class="kwd">out</span><span class="pun">.</span><span class="pln">println</span><span class="pun">(</span><span class="str">"Inside Rectangle::draw() method."</span><span class="pun">);</span> <span class="pun">}</span> <span class="pun">}</span> |
Square.java
|
1 2 3 4 5 6 |
<span class="kwd">public</span> <span class="kwd">class</span> <span class="typ">Square</span> <span class="kwd">implements</span> <span class="typ">Shape</span> <span class="pun">{</span> <span class="lit">@Override</span> <span class="kwd">public</span> <span class="kwd">void</span><span class="pln"> draw</span><span class="pun">()</span> <span class="pun">{</span> <span class="typ">System</span><span class="pun">.</span><span class="kwd">out</span><span class="pun">.</span><span class="pln">println</span><span class="pun">(</span><span class="str">"Inside Square::draw() method."</span><span class="pun">);</span> <span class="pun">}</span> <span class="pun">}</span> |
Circle.java
|
1 2 3 4 5 6 |
<span class="kwd">public</span> <span class="kwd">class</span> <span class="typ">Circle</span> <span class="kwd">implements</span> <span class="typ">Shape</span> <span class="pun">{</span> <span class="lit">@Override</span> <span class="kwd">public</span> <span class="kwd">void</span><span class="pln"> draw</span><span class="pun">()</span> <span class="pun">{</span> <span class="typ">System</span><span class="pun">.</span><span class="kwd">out</span><span class="pun">.</span><span class="pln">println</span><span class="pun">(</span><span class="str">"Inside Circle::draw() method."</span><span class="pun">);</span> <span class="pun">}</span> <span class="pun">}</span> |
Step 3
Create a Factory to generate object of concrete class based on given information.
ShapeFactory.java
|
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 |
<span class="kwd">public</span> <span class="kwd">class</span> <span class="typ">ShapeFactory</span> <span class="pun">{</span> <span class="com">//use getShape method to get object of type shape </span> <span class="kwd">public</span> <span class="typ">Shape</span><span class="pln"> getShape</span><span class="pun">(</span><span class="typ">String</span><span class="pln"> shapeType</span><span class="pun">){</span> <span class="kwd">if</span><span class="pun">(</span><span class="pln">shapeType </span><span class="pun">==</span> <span class="kwd">null</span><span class="pun">){</span> <span class="kwd">return</span> <span class="kwd">null</span><span class="pun">;</span> <span class="pun">}</span> <span class="kwd">if</span><span class="pun">(</span><span class="pln">shapeType</span><span class="pun">.</span><span class="pln">equalsIgnoreCase</span><span class="pun">(</span><span class="str">"CIRCLE"</span><span class="pun">)){</span> <span class="kwd">return</span> <span class="kwd">new</span> <span class="typ">Circle</span><span class="pun">();</span> <span class="pun">}</span> <span class="kwd">else</span> <span class="kwd">if</span><span class="pun">(</span><span class="pln">shapeType</span><span class="pun">.</span><span class="pln">equalsIgnoreCase</span><span class="pun">(</span><span class="str">"RECTANGLE"</span><span class="pun">)){</span> <span class="kwd">return</span> <span class="kwd">new</span> <span class="typ">Rectangle</span><span class="pun">();</span> <span class="pun">}</span> <span class="kwd">else</span> <span class="kwd">if</span><span class="pun">(</span><span class="pln">shapeType</span><span class="pun">.</span><span class="pln">equalsIgnoreCase</span><span class="pun">(</span><span class="str">"SQUARE"</span><span class="pun">)){</span> <span class="kwd">return</span> <span class="kwd">new</span> <span class="typ">Square</span><span class="pun">();</span> <span class="pun">}</span> <span class="kwd">return</span> <span class="kwd">null</span><span class="pun">;</span> <span class="pun">}</span> <span class="pun">}</span> |
Step 4
Use the Factory to get object of concrete class by passing an information such as type.
FactoryPatternDemo.java
|
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 |
<span class="kwd">public</span> <span class="kwd">class</span> <span class="typ">FactoryPatternDemo</span> <span class="pun">{</span> <span class="kwd">public</span> <span class="kwd">static</span> <span class="kwd">void</span><span class="pln"> main</span><span class="pun">(</span><span class="typ">String</span><span class="pun">[]</span><span class="pln"> args</span><span class="pun">)</span> <span class="pun">{</span> <span class="typ">ShapeFactory</span><span class="pln"> shapeFactory </span><span class="pun">=</span> <span class="kwd">new</span> <span class="typ">ShapeFactory</span><span class="pun">();</span> <span class="com">//get an object of Circle and call its draw method.</span> <span class="typ">Shape</span><span class="pln"> shape1 </span><span class="pun">=</span><span class="pln"> shapeFactory</span><span class="pun">.</span><span class="pln">getShape</span><span class="pun">(</span><span class="str">"CIRCLE"</span><span class="pun">);</span> <span class="com">//call draw method of Circle</span><span class="pln"> shape1</span><span class="pun">.</span><span class="pln">draw</span><span class="pun">();</span> <span class="com">//get an object of Rectangle and call its draw method.</span> <span class="typ">Shape</span><span class="pln"> shape2 </span><span class="pun">=</span><span class="pln"> shapeFactory</span><span class="pun">.</span><span class="pln">getShape</span><span class="pun">(</span><span class="str">"RECTANGLE"</span><span class="pun">);</span> <span class="com">//call draw method of Rectangle</span><span class="pln"> shape2</span><span class="pun">.</span><span class="pln">draw</span><span class="pun">();</span> <span class="com">//get an object of Square and call its draw method.</span> <span class="typ">Shape</span><span class="pln"> shape3 </span><span class="pun">=</span><span class="pln"> shapeFactory</span><span class="pun">.</span><span class="pln">getShape</span><span class="pun">(</span><span class="str">"SQUARE"</span><span class="pun">);</span> <span class="com">//call draw method of square</span><span class="pln"> shape3</span><span class="pun">.</span><span class="pln">draw</span><span class="pun">();</span> <span class="pun">}</span> <span class="pun">}</span> |
Step 5
Verify the output.
|
1 2 3 |
Inside Circle::draw() method. Inside Rectangle::draw() method. Inside Square::draw() method. |