Sun Certified Java Programmer Student Blog

Archive for the ‘Types’ Category

interface TestInterface
{
public void testMethod();
}

class ClassA
{
public void ClassAMethod(TestInterface a)
{
System.out.println(“Class A Method”);
a.testMethod();
}
}

public class ArgumentInnerClassTest
{
public void OuterClassMethod()
{
ClassA a1 = new ClassA();
a1.ClassAMethod
(
new TestInterface()
{
public void testMethod()
{
System.out.println(“Call Test Method”);
}
}
);
}
public static void main (String[] args)
{
ArgumentInnerClassTest a1 = new ArgumentInnerClassTest();
a1.OuterClassMethod();
}

}

public class MethodLocalInnerClassOuter
{
private int testVariable1 = 10;
public void outerClassMethod()
{
class MethodLocalInnerClassInner
{
public void getTestVariable1()
{
System.out.println(“Test variable 1 = “+testVariable1);
}
}
MethodLocalInnerClassInner m = new MethodLocalInnerClassInner(); //A method local inner class can only ever be instantiated inside themethod that uses it.
m.getTestVariable1();
}

public static void main (String args[])
{
MethodLocalInnerClassOuter m1 = new MethodLocalInnerClassOuter();
m1.outerClassMethod();
}
}

interface testInterface1
{
public void getTestVariable1();
}

public class AnnonymousInnerClassInterface
{
private int testVariable1 = 10;

testInterface1 t1 = new testInterface1()
{
public void getTestVariable1()
{
System.out.println(“TestVariable1 = “+testVariable1);
}
};

public void getTestVariableFromInnerClass()
{
t1.getTestVariable1();
}

public static void main (String[] args)
{
AnnonymousInnerClassInterface a1 = new AnnonymousInnerClassInterface();
a1.getTestVariableFromInnerClass();
}
}

public class AnonymousInnerClass
{
private int testVariable1 = 1;

Fruit f1 = new Fruit() //Class must extend Fruit. It is not of type Fruit. It is a Polymorphic reference.
{
public void eat()
{
System.out.println(“Eat a bannana”);
System.out.println(“Test variable 1 is: “+testVariable1);
}

/*public void getColour() //Cannot do this because no getColour is Fruit class
{
System.out.println(“Colour is yellow!);
} */
};

public void eatFood()
{
f1.eat();
}

public static void main (String args[])
{
AnonymousInnerClass a1 = new AnonymousInnerClass();
a1.eatFood();
a1.f1.eat(); //You can do this.
}
}

class Fruit
{
public void eat()
{
System.out.println(“Eat fruit”);
}
}

// D4RVCFT6PMZ9

public class InnerClassTest
{
private int testVariable1 = 1;
private int testVariable2 = 2;

void doThings()
{
class InnerClass
{
public int getTestVariable()
{
return testVariable1+testVariable2;
}
}
InnerClass ic = new InnerClass();
System.out.println(ic.getTestVariable1());
}

public static void main (String [] args)
{
InnerClassTest t1 = new InnerClassTest();
t1.doThings();
}
}

//This compiles into a class called Day.class
public enum Day
{
MONDAY, TUESDAY, WEDNESDAY,THURSDAY,FRIDAY;
}

//This compiles into a class called Today.class
{
Day day;

public Today(Day day)
{
this.day = day;
}
public void likeTest()
{
switch(day)
{
case MONDAY:
System.out.println(“Day is Monday”);
break;
case TUESDAY:
System.out.println(“Day is Tuesday”);
break;
case WEDNESDAY:
System.out.println(“Day is Wednesday”);
break;
case THURSDAY:
System.out.println(“Day is Thursday”);
break;
default:
System.out.println(“Day is Friday”);
break;
}
}
public static void main (String [] args)
{
Today d1 = new Today(Day.MONDAY);
d1.likeTest();
}

}

public enum Surgery
{
MONDAY (“Smith”, “10:00-12:00″),
TUESDAY (“Tray”, “14:00-16:00″),
WEDNESDAY (“Smith”, “14:00-16:00″),
THURSDAY (“Tray”, “10:00-12:00″),
FRIDAY (“Smith”, “10:00-12:00″);

private final String doctorName;
private final String openingHours;

Surgery (String doctorName, String openingHours)
{
this.doctorName = doctorName;
this.openingHours = openingHours;
//this.toString();
}

public static void main (String [] args)
{
for (Surgery s: Surgery.values())
{
System.out.println(“Dr “+s.doctorName+” runs a surgery (“+s.openingHours+”) on “+s);
}
}
}