Java 中的继承

Question

我正在学习如何在 Java 中使用继承。该程序的目的是编写类包含有关某些日志条目的信息，并提供设置和获取适当信息的方法。如果需要更正，请告诉我。

ArithmeLog.java

//super class ArithmeLog with three functions to capture three instances

import java.util.*;

import java.text.*;

public class ArithmeLog {

 public ArithmeLog() {

 }



 public void captid1(String a) {

      System.out.println("");

 }



 public void captid2(String SongName) {

      System.out.println("");

 }

 public void Date() {

      Date capttim = new Date( );

      SimpleDateFormat formt = new SimpleDateFormat

 ("E yyyy.MM.dd 'at' hh:mm:ss a zzz");

      System.out.println("Time is : " +

formt.format(capttim));

   }

    }

SongLog.java

//class SongLog which inheriting ArithmeLog class

import java.util.*;

import java.text.*;

public class SongLog extends ArithmeLog {

 public SongLog() {

      super();

      System.out.println("");

 }



 @Override

 public void captid1(String SongID) {

      System.out.println("SongID is: "+SongID);

 }



 @Override

 public void captid2(String SongName) {

      System.out.println("Song name is: "+SongName);

 }

 @Override

 public void Date() {

      Date capttim = new Date( );

      SimpleDateFormat formt = new SimpleDateFormat

  ("E yyyy.MM.dd 'at' hh:mm:ss a zzz");

      System.out.println(" Date and time is : " +

  formt.format(capttim));

 }

 }

 AdLog.java

// AdLog class which inheriting ArithmeLog class

import java.util.*;

import java.text.*;

 public class AdLog extends ArithmeLog {

 public AdLog() {

      super();

      System.out.println("");

 }



 @Override

 public void captid1(String AdvertisementID) {

 System.out.println("AdvertisementID is:"+AdvertisementID);

 }



 @Override

 public void captid2(String AdvertiserID) {

      System.out.println("AdvertiserID is:"+AdvertiserID);

 }

 @Override

 public void Date() {

      Date capttim = new Date( );

      SimpleDateFormat formt = new SimpleDateFormat

 ("E yyyy.MM.dd 'at' hh:mm:ss a zzz");

      System.out.println(" Date and time is : " +

 formt.format(capttim));

 }

 }

  Mainpgm.java

// main class creating objects of classes and calling methods

public class Mainpgm {

 public static void main(String[] args) {

      //creating first object of classes

      ArithmeLog animal = new ArithmeLog();

      AdLog ao1 = new AdLog();

      SongLog so1 = new SongLog();

      System.out.println();

      ao1.captid1("1");

      ao1.captid2("7");

      ao1.Date();

      so1.captid1("1");

      so1.captid2("songg1");

      so1.Date();

      //creating second object of classes

      AdLog ao2 = new AdLog();

      SongLog so2 = new SongLog();

      ao2.captid1("2");

      ao2.captid2("ad2");

      ao2.Date();

      so2.captid1("2");

      so2.captid2("songg2");

      so2.Date();

      //creating third object of classes

      AdLog ao3 = new AdLog();

      SongLog so3 = new SongLog();

      ao3.captid1("3");

      ao3.captid2("ad3");

      ao3.Date();

      so3.captid1("6");

      so3.captid2("songg3");

      so3.Date();



    }

  }

Answer 1

根据您的评论，所有这些都在 1 个文件中吗？

每个 'section' 都应该在它自己的文件中。因此，一个名为 ArithmeLog.java 的文件包含该行下面的所有内容，直到 SongLog.java，然后是一个名为 SongLog.java 的文件，其中包含下面的所有内容，等等

Java 中的继承

Inheritence in Java

java

methods

inheritance

subclass

superclass