Java

InterfaceJAVAinterface

Java

.java
.class

Java 8 default
static final

, public abstract public abstract
public static final public private

1.
2. public static final
3. ( static )
4.

JDK 1.8

JDK 1.8 "" default Java 8

JDK 1.9 private Java 9

[] interface [extends ] { // // }

Interface

NameOfInterface.java

/* : NameOfInterface.java */ import java.lang.*; // public interface NameOfInterface { // final, static // }

abstract
abstract

Animal.java

/* : Animal.java */ interface Animal { public void eat(); public void travel(); }

implementsImplementsclass

...implements [, , ..., ...] ...

MammalInt.java

/* : MammalInt.java */ public class MammalInt implements Animal{ public void eat(){ System.out.println("Mammal eats"); } public void travel(){ System.out.println("Mammal travels"); } public int noOfLegs(){ return 0; } public static void main(String args[]){ MammalInt m = new MammalInt(); m.eat(); m.travel(); } }

Mammal eats
Mammal travels

extends

SportsHockeyFootball

// : Sports.java public interface Sports { public void setHomeTeam(String name); public void setVisitingTeam(String name); } // : Football.java public interface Football extends Sports { public void homeTeamScored(int points); public void visitingTeamScored(int points); public void endOfQuarter(int quarter); } // : Hockey.java public interface Hockey extends Sports { public void homeGoalScored(); public void visitingGoalScored(); public void endOfPeriod(int period); public void overtimePeriod(int ot); }

HockeySportsHockey

FootballSports

Java

extends

public interface Hockey extends Sports, Event

Sports Event

java.awt.event MouseListener java.util.EventListener

package java.util; public interface EventListener {}

EventListenerJava APIEventListenerJava(JVM)
()

interface Test{ // default String get(String aa){ System.out.println("jdk1.8..."); return ""; } // static void staticmethod(){ System.out.println(""); } }

//USB interface USB { void read(); void write(); } // U class YouPan implements USB { @Override public void read() { System.out.println("UUSB"); } @Override public void write() { System.out.println("UUSB"); } }

// public interface Inter { void show(); // default void method() { // System.out.println(""); } static void test(){ // System.out.println(""); } } // public class Interlmpl implements Inter { @Override public void show() { System.out.println("show"); } } // public class InterDemo { public static void main(String[] args) { Inter i = new Interlmpl(); i.show(); // i.method(); //default Inter.test(); //, } }

165

2. public abstract

5. public static final

fang9 (2017-05-23)

115

9 (2017-10-23)

JDK1.8

1 default

2 static

default

9 (2018-01-11)

1 public static final
2 public abstract

//
public interface People {
    int age=10;
    String name=""; //   public static final 
    public void eat();
}

public static final

8 (2018-06-27)

instanceof

if(obj instanceof Cloneable) {………}

Ejb servlet serialialbe

java.io.Serializable serialVersionUID java serialVersionUID
java.lang.Cloneable Object.clone() . Object.clone Cloneable Object clone CloneNotSupportedException
java.util.RandomAccess
java.rmi.RemoteRemote java.rmi.Remote

Xander6638 (2018-07-15)

interface Fu {
    public abstract void method();
}
class Zi implements Fu {
    public void method(){
        System.out.println(“”);
    }
}
//
Fu fu = new Zi();

1abstract class Java interface
2. abstract class abstarct interface static final interface abstract
3.abstract class interface abstract class "is-a" interface "has-a"
4.
5. public static final
6. friendly
7. public,abstract

: abstract class interface Java

Luochy8 (2018-07-31)

Cheese6 (2020-05-15)

5 (2021-09-02)

--

Java

Java

Java

NameOfInterface.java

Animal.java

MammalInt.java

9