Those Who Know HistoryAre Doomed to Watch Others Repeat It

Who Is This Guy?

Guy Royse, Consultant

Pillar Technology

guy@guyroyse.com

@guyroyse

“History doesn’t repeat itself, but it often

rhymes”

—Mark Twain

Java is theNew COBOL

“COBOL has almost no fervent

enthusiasts. As a programming tool, it has roughly the

sex appeal of a wrench.”

Charles Petzold

CompletelyObsoleteBusinessOrientedLanguage

I had a problem that I tried tosolve with Java.

Now I have a ProblemFactory.

And anAbstractProblemFactoryManager.

ASimple Problem

Java Class Diagram

PhoneValidatorboolean validate(Phone)

AddressValidatorboolean

validate(Address)

ContactValidatorboolean

validate(Contact)

COBOL System Diagram

CONTACT-VALIDATOR

ADDRESS-VALIDATOR

PHONE-VALIDATOR

Java Data Structures

PhoneString areaCodeString exchangeString number

AddressString streetString city

String stateString zipCode

ContactString name

Address addressPhone cell

Phone home

COBOL Data Structures

01 CN-CONTACT. 05 CN-NAME PIC X(40). 05 CN-ADDRESS. 10 CN-ADDR-STREET PIC X(30). 10 CN-ADDR-CITY PIC X(20). 10 CN-ADDR-STATE PIC X(2). 10 CN-ADDR-ZIP-CODE PIC X(5). 05 CN-HOME-PHONE. 10 CN-HOME-AREA-CD PIC 9(3). 10 CN-HOME-EXCHANGE PIC 9(3). 10 CN-HOME-NUMBER PIC 9(4). 05 CN-CELL-PHONE. 10 CN-CELL-AREA-CD PIC 9(3). 10 CN-CELL-EXCHANGE PIC 9(3). 10 CN-CELL-NUMBER PIC 9(4).

01 CN-CONTACT. 05 CN-NAME PIC X(40). 05 CN-ADDRESS. 10 CN-ADDR-STREET PIC X(30). 10 CN-ADDR-CITY PIC X(20). 10 CN-ADDR-STATE PIC X(2). 10 CN-ADDR-ZIP-CODE PIC X(5). 05 CN-HOME-PHONE. 10 CN-HOME-AREA-CD PIC 9(3). 10 CN-HOME-EXCHANGE PIC 9(3). 10 CN-HOME-NUMBER PIC 9(4). 05 CN-CELL-PHONE. 10 CN-CELL-AREA-CD PIC 9(3). 10 CN-CELL-EXCHANGE PIC 9(3). 10 CN-CELL-NUMBER PIC 9(4).

public class Contact { private String name; private Phone home; private Phone cell; private Address address;

public String getName() { return name; } public void setName(String name) { this.name = name; }

... more setters and getters here ...}

public class Phone { private String areaCode; private String exchange; private String number;

... setters and getters here ...}

public class Address { private String street; private String city; private String state; private String zipCode;

... setters and getters here ...}

IDENTIFICATION DIVISION.PROGRAM-ID. CONTACT-VALIDATOR.

PROCEDURE DIVISION USING CN-IS-VALID, CN-CONTACT.

MAIN-LINE. PERFORM VALIDATE-NAME. CALL ADDRESS-VALIDATOR USING CN-ADDRESS, WS-ADDRESS-IS-VALID. CALL PHONE-VALIDATOR USING CN-HOME-PHONE, WS-HOME-PH-IS-VALID CALL PHONE-VALIDATOR USING CN-CELL-PHONE, WS-CELL-PH-IS-VALID. PERFORM DETERMINE-IF-VALID. GOBACK.

VALIDATE-NAME. MOVE ‘Y’ TO WS-NAME-IS-VALID. IF CN-NAME IS SPACES MOVE ‘N’ TO WS-NAME-IS-VALID.

DETERMINE-IF-VALID. MOVE ‘N’ to CN-IS-VALID. IF WS-NAME-IS-VALID IS ‘Y’ AND WS-HOME-PH-IS-VALID IS ‘Y’ AND WS-CELL-PH-IS-VALID IS ‘Y’ AND WS-ADDRESS-IS-VALID IS ‘Y’ MOVE ‘Y’ TO CN-IS-VALID.

public class ContactValidator {

private PhoneValidator phoneValidator = new PhoneValidator(); private AddressValidator addrValidator = new AddressValidator();

public boolean validate(Contact cntct) {

boolean valid = validateName(cntct.getName());

valid &= addrValidator.validate( cntct.getAddress());

valid &= phoneValidator.validate( cntct.getHome());

valid &= phoneValidator.validate( cntct.getCell());

return valid;

}

private void validateName(String name) { return !StringUtils.isEmpty(name); }

}

Automating the Process

Node isSingle-

Threaded

So Why Do We Keep Reinventing the Past and Calling it the Future?

Peoplein thePastWere Dumb

“I’m just a cave man. Your world frightens and confuses

me.”

“Look back over the past, with its changing empires that rose and fell,

and you can foresee the future

too.”

― Marcus Aurelius,

Meditations

“If history is deprived of the

Truth, we are left with nothing but an

idle, unprofitable tale.”

― Polybius,The Rise of the Roman Empire

Anacyclosis

Basic Cycle

How Projects Run

How We Code

How We Design Applications

The 40s and 50s

Computing Timeline40s & 50s 60s & 70s 80s 90s 2000s 2010s ???

Server-side

Client-side

ENIAC

UNIVAC

Z3Mark 1

The 60s and 70s

Computing Timeline40s & 50s 60s & 70s 80s 90s 2000s 2010s ???

Server-side

Client-side

ENIAC

Mainframes

TeletypesTerminals

CICS

UNIVAC

Z3Mark 1

UNIX

The Late 70s

Computing Timeline40s & 50s 60s & 70s 80s 90s 2000s 2010s ???

Server-side

Client-side

ENIAC

Mainframes

TeletypesTerminals

CICS

UNIVAC

Z3Mark 1

UNIX

Early PCs

The 80s

Computing Timeline40s & 50s 60s & 70s 80s 90s 2000s 2010s ???

Server-side

Client-side

ENIAC

Mainframes

TeletypesTerminals

CICS

UNIVAC

Z3Mark 1

UNIX

PCs

Early PCs

The 90s

Computing Timeline40s & 50s 60s & 70s 80s 90s 2000s 2010s ???

Server-side

Client-side

ENIAC

Mainframes

TeletypesTerminals

CICS

UNIVAC

Z3Mark 1

UNIX

PCs

Early PCs

ClientServer

Browser

Internet

In The Year 2000

Computing Timeline40s & 50s 60s & 70s 80s 90s 2000s 2010s ???

Server-side

Client-side

ENIAC

Mainframes

TeletypesTerminals

CICS

UNIVAC

Z3Mark 1

UNIX

PCs

Early PCs

ClientServer

Browser

Mobile

Internet

AJAX

2010s

Computing Timeline40s & 50s 60s & 70s 80s 90s 2000s 2010s ???

Server-side

Client-side

ENIAC

Mainframes

TeletypesTerminals

CICS

UNIVAC

Z3Mark 1

UNIX

PCs

Early PCs

ClientServer

Browser

Mobile

Internet

HTML5

Cloud

PiAJAX

Computing Timeline40s & 50s 60s & 70s 80s 90s 2000s 2010s ???

Server-side

Client-side

ENIAC

Mainframes

TeletypesTerminals

CICS

UNIVAC

Z3Mark 1

UNIX

PCs

Early PCs

ClientServer

Browser

Mobile

Internet

HTML5

Cloud

Pi

?

AJAX

“It is not worthwhile to try to keep history from repeating itself, for man's character will

always make the preventing of the

repetitions impossible.”

— Mark Twain

Guy Royse, Consultant

Pillar Technology

guy@guyroyse.com

@guyroyse