4.57 Interface Exercises

1:

/* Cat dog case, add extra function Analysis of high jump: from concrete to abstract Cat: name, age to eat, sleep Dog: name, age to eat, sleep because there is a common function, so, extract a parent class: Animal: Name, age to eat (); sleep () {} Cat: Inherit from Animal dog: The Extra function inherited from animal high jump is a new extension function, so to define an interface interface: High jump part of the cat: the realization of high jump part of the dog: the realization of high jump; From abstraction to concrete use: Define high jump interfaces using specific class *///interface  jumpping {//  High jump function Public abstract void jump ();}   Define abstract class abstract class animal {//  name private string name;//  age Private  int age;public animal ()  {}public animal (string name, int age)  { This.name = name;this.age = age;} Public string getname ()  {return name;} Public void setname (String name)  {this.name = name;} Public int getage ()  {return age;} Public void setage (Int age)  {this.age = age;}   Eat ();p ublic abstract void eat ();//  sleeping () {}public void sleep ()  { System.out.println ("Sleeping");}}   Specific Cat class Class cat extends animal {public&nbsP Cat ()  {}public cat (string name, int age)  {super (name, age);} Public void eat ()  {system.out.println ("Cat eats Fish");}}   Specific Dog class Class dog extends animal {public dog ()  {}public dog (String  name, int age)  {super (name, age);} Public void eat ()  {system.out.println ("Dog eats Meat");}}   Cat class jumpcat extends cat implements jumpping {public  with high jump function Jumpcat ()  {}public jumpcat (string name, int age)  {super (name, age);} Public void jump ()  {system.out.println ("High Jump Cat");}}   Dog class jumpdog extends dog implements jumpping {public  with high jump function Jumpdog ()  {}public jumpdog (string name, int age)  {super (name, age);} Public void jump ()  {system.out.println ("High Jump Dog");}} Class interfacetest {public static void main (StriNg[] args)  {//  define high jump cat and Test jumpcat jc = new jumpcat (); Jc.setname ("Doraemon"); Jc.setage (3); System.out.println (Jc.getname ()  +  "---"  + jc.getage ()); Jc.eat (); Jc.sleep (); Jc.jump (); System.out.println ("-----------------"); Jumpcat jc2 = new jumpcat ("Garfield",  2); System.out.println (Jc2.getname ()  +  "---"  + jc2.getage ()); Jc2.eat (); Jc2.sleep (); Jc2.jump () ;//  defines the high jump dog and carries out the test by doing it himself. }}

2:

/* Teacher and student case, add extra function Analysis of smoking: from concrete to abstract teacher: name, age, eat, sleep students: name, age, eat, sleep due to the common function, extract a parent class, human. Human: Name, age eat (); sleeping () {} The extra function of smoking is not a person or teacher, or a student should have it at first, so define it as an interface smoking interface. Part of the teacher smoking: Realizing the Smoking interface part students smoking: Realizing the Smoking interface realization: From abstraction to concrete use: specific *///defines the smoking interface interface smoking {//  the abstract method of smoking public  Abstract void smoke ();}   Definition abstract Human abstract class person {//  name private string name;//  age Private  int age;public person ()  {}public person (string name, int age)  { This.name = name;this.age = age;} Public string getname ()  {return name;} Public void setname (String name)  {this.name = name;} Public int getage ()  {return age;} Public void setage (Int age)  {this.age = age;}   Eat ();p ublic abstract void eat ();//  sleeping () {}public void sleep ()  { System.out.println ("Sleep-Awake");}}   Concrete Teacher Class class teacher extends Person {public teacher ()  {}public teacher (string name, int age)  {super (name, age);} Public void eat ()  {system.out.println ("eating cabbage");}}   Specific Student class class student extends person {public student ()  {}public  Student (string name, int age)  {super (name, age);} Public void eat ()  {system.out.println ("Eat Pork");}}   Smoking teacher Class smokingteacher extends teacher implements smoking {public  smokingteacher ()  {}public smokingteacher (string name, int age)  {super (name ,  age);} Public void smoke ()  {system.out.println ("Smoking Teacher");}   Smoking Students Class smokingstudent extends student implements smoking {public  smokingstudent ()  {}public smokingstudent (string name, int age)  {super (name ,  age);} Public void smoke ()  {SYSTEM.OUt.println ("smoking Student");}} Class interfacetest2 {public static void main (String[] args)  {//  Test student smokingstudent ss = new smokingstudent (); Ss.setname ("abc"); Ss.setage (27); System.out.println (Ss.getname ()  +  "---"  + ss.getage ()); Ss.eat (); Ss.sleep (); Ss.smoke (); System.out.println ("-------------------"); Smokingstudent ss2 = new smokingstudent ("EFG",  30); System.out.println (Ss2.getname ()  +  "---"  + ss2.getage ()); Ss2.eat (); Ss2.sleep (); Ss2.smoke () ;//  Test Teacher}}

4.57 Interface Exercises