describe the code in detail add comment lines
describe the code in detail add comment lines
package com.templatepattern;
public class TemplatePatternTest1 {
public static void main(String[] args) {
String connectionString = "server=192.168.0.7";
String username = "learner";
String password = "designPatterns";
StudentRegistration sr = new DatabaseBasedStudentRegistration(connectionString, username, password);
System.out.println();
Person p1 = new Person("patrick", "nick");
System.out.println("Registering " + p1);
sr.register(p1);
System.out.println();
Person p2 = new Person("zayn", "nick");
System.out.println("Registering " + p2);
sr.register(p2);
System.out.println();
}
}
abstract class StudentRegistration {
// template method
final Student register(Person person) {
if (checkPerson(person)) {
startOperation();
try {
int studentId = getNewIdentity(person);
Student student = new Student(person, studentId);
completeOperation();
return student;
}
catch (Exception e) {
cancelOperation();
promptError(e.getMessage());
}
}
else {
promptError(person + " is not a valid citizen.");
}
return null;
}
abstract void startOperation();
abstract void completeOperation();
abstract void cancelOperation();
abstract boolean checkPerson(Person person);
abstract int getNewIdentity(Person person);
abstract void promptError(String errorMessage);
}
class DatabaseConnection {
DatabaseConnection(String connectionString, String username, String password) {
System.out.println("Connect to
}
void beginTransaction() {
System.out.println("Begin Transaction");
}
void commitTransaction() {
System.out.println("Commit Transaction");
}
void rollbackTransaction() {
System.out.println("Rollback Transaction");
}
}
class DatabaseBasedStudentRegistration extends StudentRegistration {
private final DatabaseConnection connection;
DatabaseBasedStudentRegistration(String connectionString, String username, String password) {
connection = new DatabaseConnection(connectionString, username, password);
}
@Override
void startOperation() {
connection.beginTransaction();
}
@Override
void completeOperation() {
connection.commitTransaction();
}
@Override
void cancelOperation() {
connection.rollbackTransaction();
}
@Override
boolean checkPerson(Person person) {
return (person.toString().length() > 10);
}
@Override
int getNewIdentity(Person person) {
return Math.abs(person.toString().hashCode()) % 100000000;
}
@Override
void promptError(String errorMessage) {
System.out.println(errorMessage);
}
}
class Person {
final String name;
final String surname;
Person(String name, String surname) {
this.name = name;
this.surname = surname;
}
@Override
public String toString() {
return name + " " + surname;
}
}
class Student extends Person {
final int studentId;
Student(String name, String surname, int studentId) {
super(name, surname);
this.studentId = studentId;
System.out.println(this + " is created");
}
Student(Person person, int studentId) {
super(person.name, person.surname);
this.studentId = studentId;
System.out.println(this + " is created");
}
@Override
public String toString() {
return super.toString() + ", ID = " + studentId;
}
}
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