conditional logic to polymorphysm

src/refactoring/ChildrensPrice.java

@@ -0,0 +1,18 @@
+package refactoring;
+
+public class ChildrensPrice extends Price {
+
+	@Override
+	double getCharge(int daysRented) {
+		double result = 1.5;
+		if (daysRented > 3)
+			result += (daysRented - 3) * 1.5;
+		return result;
+	}
+
+	@Override
+	int getPriceCode() {
+		return Movie.CHILDRENS;
+	}
+
+}

src/refactoring/Movie.java

@@ -1,53 +1,46 @@
 package refactoring;
 
-
 public class Movie {
 	public static final int CHILDRENS = 2;
 	public static final int REGULAR = 0;
 	public static final int NEW_RELEASE = 1;
 	private String _title;
-	private int _priceCode;
+	private Price _price;
 
 	public Movie(String title, int priceCode) {
 		_title = title;
-		_priceCode = priceCode;
+		setPriceCode(priceCode);
 	}
-	
+
 	public double getCharge(int daysRented) {
-		double result = 0;
-		// determine amounts for each line
-		switch (getPriceCode()) {
-		case Movie.REGULAR:
-			result += 2;
-			if (daysRented > 2)
-				result += (daysRented - 2) * 1.5;
-			break;
-		case Movie.NEW_RELEASE:
-			result += daysRented * 3;
-			break;
-		case Movie.CHILDRENS:
-			result += 1.5;
-			if (daysRented > 3)
-				result += (daysRented - 3) * 1.5;
-			break;
-		}
-		return result;
+		return _price.getCharge(daysRented);
 	}
-	
+
 	public int getFrequentRenterPoints(int daysRented) {
-		if (getPriceCode() == Movie.NEW_RELEASE
-				&& daysRented > 1)
+		if (getPriceCode() == Movie.NEW_RELEASE && daysRented > 1)
 			return 2;
 		else
 			return 1;
 	}
 
 	public int getPriceCode() {
-		return _priceCode;
+		return _price.getPriceCode();
 	}
 
 	public void setPriceCode(int arg) {
-		_priceCode = arg;
+		switch (arg) {
+		case REGULAR:
+			_price = new RegularPrice();
+			break;
+		case CHILDRENS:
+			_price = new ChildrensPrice();
+			break;
+		case NEW_RELEASE:
+			_price = new NewReleasePrice();
+			break;
+		default:
+			throw new IllegalArgumentException("Incorrect Price Code");
+		}
 	}
 
 	public String getTitle() {

src/refactoring/NewReleasePrice.java

@@ -0,0 +1,15 @@
+package refactoring;
+
+public class NewReleasePrice extends Price {
+
+	@Override
+	double getCharge(int daysRented) {
+		return daysRented * 3;
+	}
+
+	@Override
+	int getPriceCode() {
+		return Movie.NEW_RELEASE;
+	}
+
+}

src/refactoring/Price.java

@@ -0,0 +1,9 @@
+package refactoring;
+
+public abstract class Price {
+
+	abstract double getCharge(int daysRented);
+
+	abstract int getPriceCode();
+
+}

src/refactoring/RegularPrice.java

@@ -0,0 +1,18 @@
+package refactoring;
+
+public class RegularPrice extends Price {
+
+	@Override
+	double getCharge(int daysRented) {
+		double result = 2;
+			if (daysRented > 2)
+				result += (daysRented - 2) * 1.5;
+		return result;
+	}
+
+	@Override
+	int getPriceCode() {
+		return Movie.REGULAR;
+	}
+
+}