how to inherit from abstract class in java

(Request,response);} catch (excetpion e) { ???? Log exception information } ? ? ? ? ? ?} ? ? ? ? ? ?} protected abstract void Doservice (HttpServletRequest request, httpservletresponse response) throws Ioexcetion, servletexception;//Note that access rights are defined as protected, rigorous, because it is intended for subclasse

employees of the company, programmers and managers can be extracted. Establish the system. *///describe the employee. Abstract classemployee{PrivateString name; PrivateString ID; Private DoublePay ; Employee (String name,string ID,DoublePay ) { This. Name =name; This. ID =ID; This. Pay =Pay ; } Public Abstract voidWork (); }//describe the programmer. classProgrammerextendsemployee{Programmer

, can not be rewritten;A 3,final modified variable is a constant that can only be assigned once.Abstract class: Produce:When describing things, there is not enough information to describe a thing, when the thing is abstract, its function is not specific, these non-specific functions need to be identified in the class, using the keyword in

Abstract classes are used in the Java language to define abstractions. The following example:Employee.java File Code:/* File name: Employee.java */Public abstract class Employee{private String name;Private String address;private int number;Public Employee (string name, string address, int number){SYSTEM.OUT.PRINTLN ("C

object type, but if a parent class is too many subclasses, this kind of judgment is very cumbersome * How to design the parent class? * 1. The parent class is typically designed as an abstract class or interface, where the interface is preferred, and the

). Multiple inheritance of interface In the inheritance of Java classes, a derived class can have only one base class. In other words, a class cannot inherit more than one class at a time. In Java, interface can inherit more th

) throwsIOException,ClassNotFoundException{ employeeid=in.readint (); employeeName= (String) in.readobject ();} @Override publicvoidwriteexternal (objectoutputout) throwsioexception{out.writeint ( EMPLOYEEID); out.writeobject (EmployeeName); }} Comparison of abstract classes and interfaces Parameters Abstract class Interface

classes can have constructors Interfaces cannot have constructors Differences from normal Java classes Except that you can't instantiate an abstract class, it's no different than a normal Java class. Interfaces are completely different types

[] args) {3Goddess G =Newgoddess ();4G.setname ("Tong Tong");5 G.say ();6System.out.println ("--------------------------");7Uglywomen U =Newuglywomen ();8U.setname ("Small Buns");9 U.say ();Ten } One } A - //Women - //Abstract represents the declaration of an abstraction class the Abstract classwomen{ - PrivateString name; - PublicString GetName () { -

(); - } + Abstract classBextendsa{ A Public Abstract voidmethod2 (); at } - classCextendsb{ - Public voidmethod1 () { - //C method1 - } - Public voidmethod2 () { in //C method2 - } to}For Class C, there will be no chance of inheriting other parent classes.To sum up, interfaces and abstr