A simple example of java polymorphism: first create an interface; then create two classes to determine the content of the speech; then print the time while speaking; and finally create a test class to run.
Simple example of java polymorphism:
The three necessary conditions for polymorphism (implementation):
Need to have inheritance (inherit class, inherit abstract class, implement interface)
Need to have overriding
Reference execution of parent type subtype
Example: Using polymorphism to realize speaking and printing the time of saying this sentence
Ideas and code:
1. Since I don’t know that the content of the speech is too abstract, I created an interface
public interface TimeSpeek {
public abstract void getTimeSpeek();
}2. The methods in the interface need to be implemented, so now I need to create two classes to determine the content of the speech
第一句話
public class SpeekOne implements TimeSpeek {
@Override
public void getTimeSpeek() {
// TODO Auto-generated method stub
System.out.println("停車坐愛楓林晚");
}
}
第二句話
public class SpeekTwo implements TimeSpeek {
@Override
public void getTimeSpeek() {
// TODO Auto-generated method stub
System.out.println("霜葉紅于二月花");
}
}3. After the content of the speech is determined, you need to print the time while speaking
import java.util.Date;
public class GetTime {
public GetTime(TimeSpeek getTimeSpeek) {
this.getTime(getTimeSpeek);
}
public void getTime(TimeSpeek getTimeSpeek) {
System.out.println("開始時(shí)間：" + new Date().getTime());
getTimeSpeek.getTimeSpeek();
}
}4. Create a test class and run
public class Test {
public static void main(String[] args) {
SpeekOne so = new SpeekOne();
SpeekTwo st = new SpeekTwo();
new GetTime(so);
new GetTime(st);
}
}Get the result through the above steps:
開始時(shí)間：1565510695244 停車坐愛楓林晚 開始時(shí)間：1565510695245 霜葉紅于二月花
Related learning recommendations: java basics
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