Code examples for interfaces

****************************
Code examples for interfaces:

    * Class1.java implements Interface1.java
    * Abstract Class2.java implements Interface1.java and Interface2.java
    * Class3.java extends abstract class Class2.java
    * Interface3.java extends Interface1.java and Interface2.java
***************************
~~~~~~~~~~~~~~~~~~~~~~~~~~~
Class1.java 
~~~~~~~~~~~~~~~~~~~~~~~~~~~

// This class is not abstract, so it must provide 
// implementations of method1 and method2.

public class Class1 extends SomeClass
                    implements Interface1 {
  public ReturnType1 method1(ArgType1 arg) {
    someCodeHere();
    ...
  }
                      
  public ReturnType2 method2(ArgType2 arg) {
        someCodeHere();
    ...
  }

  ...
}
>>>>>>>>>>>>>>>>>>>>>>>>>>
~~~~~~~~~~~~~~~~~~~~~~~~~~
Interface1.java
~~~~~~~~~~~~~~~~~~~~~~~~~~
public interface Interface1 {
   ReturnType1 method1(ArgType1 arg);
  ReturnType2 method2(ArgType2 arg);
}
>>>>>>>>>>>>>>>>>>>>>>>>>>
~~~~~~~~~~~~~~~~~~~~~~~~~~
Abstract Class2.java implements Interface1.java and Interface2.java
~~~~~~~~~~~~~~~~~~~~~~~~~~
Class2.java 
~~~~~~~~~~~~~~~~~~~~~~~~~~

// This class is abstract, so does not have to provide
// implementations of the methods of Interface 1 and 2.

public abstract class Class2 extends SomeOtherClass
                             implements Interface1,
                                        Interface2 {
  ...
}
>>>>>>>>>>>>>>>>>>>>>>>>>
~~~~~~~~~~~~~~~~~~~~~~~~~
Interface2.java
~~~~~~~~~~~~~~~~~~~~~~~~~

public interface Interface2 {
  ReturnType3 method3(ArgType3 arg);
}
~~~~~~~~~~~~~~~~~~~~~~~~~
# Class3.java extends abstract class Class2.java 
~~~~~~~~~~~~~~~~~~~~~~~~~
Class3.java
>>>>>>>>>>>>>>>>>>>>>>>>>

// This class is not abstract, so it must provide
// implementations of method1, method2, and method3.

public class Class3 extends Class2 {
  public ReturnType1 method1(ArgType1 arg) {
    someCodeHere();
    ...
  }
                      
  public ReturnType2 method2(ArgType2 arg) {
       someCodeHere();
    ...
  }

  public ReturnType3 method3(ArgType3 arg) {
     someCodeHere();
    ...
  }

  ...
}
>>>>>>>>>>>>>>>>>>>>>>>
# Interface3.java extends Interface1.java and Interface2.java
>>>>>>>>>>>>>>>>>>>>>>>
~~~~~~~~~~~~~~~~~~~~~~
Interface3.java 
~~~~~~~~~~~~~~~~~~~~~~

// This interface has three methods (by inheritance) and 
// two constants.

public interface Interface3 extends Interface1,
                                    Interface2 {
  int MIN_VALUE = 0;
  int MAX_VALUE = 1000;
}
<<<<<<<<<<<<<<<<<<<<<