How to implement the Observer pattern in java

This article is about how to achieve the observer mode in java. I think it is very practical, so I share it with you. I hope you can get something after reading this article. Let's take a look at it.

Public class Teacher extends Observable {private String content; public void setHomework (final String content) {this.content = content; System.out.println ("the assignment is:" + content); / * * Mark that the object has been changed before you can notify * / setChanged () / * notify the observer that the observer update method * / notifyObservers () will be called;} public String getContent () {return this.content;}} public class Student implements Observer {private final Observable observable; private final String name; public Student (Observable observable, String name) {this.observable = observable; this.name = name Observable.addObserver (this);} @ Override public void update (Observable o, Object arg) {if (o instanceof Teacher) {Teacher teacher = (Teacher) o; System.out.println (name + "get job information:" + teacher.getContent ()) } public class Test {public static void main (String [] args) {/ * instance observable * / Teacher teacher = new Teacher (); Student S1 = new Student (teacher, "Zhang San"); Student S2 = new Student (teacher, "Li Si"); Student S3 = new Student (teacher, "Wang Wu") Teacher.setHomework ("question 6 on page 2"); teacher.setHomework ("question 7 on page 3"); teacher.setHomework ("question 8 on page 5");}}

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The above is how to implement the observer mode in java. The editor believes that there are some knowledge points that we may see or use in our daily work. I hope you can learn more from this article. For more details, please follow the industry information channel.