次の例は、ファクトリー・データおよびメソッドの定義を示すために前の例を更新したものです。
次の更新が示されています。
(前の例は、例: メソッドの定義、例: クライアントの定義、および 例: サブクラスの定義 (メソッドに関して)でした。)
また、上記の例の完全なソース・コードが COBOL インストール・ディレクトリーの samples サブディレクトリーに入っています。(Windows 環境変数 RDZvrINSTDIR は、COBOL インストール・ディレクトリーのロケーションを指定します。v は Rational Developer for System z のバージョン番号、および r はリリース番号です。) この samples サブディレクトリー内の MAKE ファイルを使用して、コードのコンパイルとリンクを行うことができます。
cbl thread,pgmname(longmixed),lib
Identification Division.
Class-id. Account inherits Base.
Environment Division.
Configuration section.
Repository.
Class Base is “java.lang.Object”
Class Account is “Account”.
*
Identification division.
Factory.
Data division.
Working-storage section.
01 NumberOfAccounts pic 9(6) value zero.
*
Procedure Division.
*
* createAccount method to create a new Account
* instance, then invoke the OBJECT paragraph's init
* method on the instance to initialize its instance data:
Identification Division.
Method-id. “createAccount”.
Data division.
Linkage section.
01 inAccountNumber pic S9(6) binary.
01 outAccount object reference Account.
* Facilitate access to JNI services:
Copy JNI.
Procedure Division using by value inAccountNumber
returning outAccount.
* Establish addressability to JNI environment structure:
Set address of JNIEnv to JNIEnvPtr
Set address of JNINativeInterface to JNIEnv
Invoke Account New returning outAccount
Invoke outAccount “init” using by value inAccountNumber
Add 1 to NumberOfAccounts.
End method “createAccount”.
*
End Factory.
*
Identification division.
Object.
Data division.
Working-storage section.
01 AccountNumber pic 9(6).
01 AccountBalance pic S9(9) value zero.
*
Procedure Division.
*
* init method to initialize the account:
Identification Division.
Method-id. “init”.
Data division.
Linkage section.
01 inAccountNumber pic S9(9) binary.
Procedure Division using by value inAccountNumber.
Move inAccountNumber to AccountNumber.
End method “init”.
*
* getBalance method to return the account balance:
Identification Division.
Method-id. “getBalance”.
Data division.
Linkage section.
01 outBalance pic S9(9) binary.
Procedure Division returning outBalance.
Move AccountBalance to outBalance.
End method “getBalance”.
*
* credit method to deposit to the account:
Identification Division.
Method-id. “credit”.
Data division.
Linkage section.
01 inCredit pic S9(9) binary.
Procedure Division using by value inCredit.
Add inCredit to AccountBalance.
End method “credit”.
*
* debit method to withdraw from the account:
Identification Division.
Method-id. “debit”.
Data division.
Linkage section.
01 inDebit pic S9(9) binary.
Procedure Division using by value inDebit.
Subtract inDebit from AccountBalance.
End method “debit”.
*
* print method to display formatted account number and balance:
Identification Division.
Method-id. “print”.
Data division.
Local-storage section.
01 PrintableAccountNumber pic ZZZZZZ999999.
01 PrintableAccountBalance pic $$$$,$$$,$$9CR.
Procedure Division.
Move AccountNumber to PrintableAccountNumber
Move AccountBalance to PrintableAccountBalance
Display “ Account: ” PrintableAccountNumber
Display “ Balance: ” PrintableAccountBalance.
End method “print”.
*
End Object.
*
End class Account.
cbl thread,pgmname(longmixed),lib
Identification Division.
Class-id. CheckingAccount inherits Account.
Environment Division.
Configuration section.
Repository.
Class CheckingAccount is “CheckingAccount”
Class Check is “Check”
Class Account is “Account”.
*
Identification division.
Factory.
Data division.
Working-storage section.
01 NumberOfCheckingAccounts pic 9(6) value zero.
*
Procedure Division.
*
* createCheckingAccount overloaded method to create a new
* CheckingAccount instance with a default balance, invoke
* inherited instance method init to initialize the account
* number, and increment factory data tally of checking accounts:
Identification Division.
Method-id. “createCheckingAccount”.
Data division.
Linkage section.
01 inAccountNumber pic S9(6) binary.
01 outCheckingAccount object reference CheckingAccount.
* Facilitate access to JNI services:
Copy JNI.
Procedure Division using by value inAccountNumber
returning outCheckingAccount.
* Establish addressability to JNI environment structure:
Set address of JNIEnv to JNIEnvPtr
Set address of JNINativeInterface to JNIEnv
Invoke CheckingAccount New returning outCheckingAccount
Invoke outCheckingAccount “init”
using by value inAccountNumber
Add 1 to NumberOfCheckingAccounts.
End method “createCheckingAccount”.
*
* createCheckingAccount overloaded method to create a new
* CheckingAccount instance, invoke inherited instance methods
* init to initialize the account number and credit to set the
* balance, and increment factory data tally of checking accounts:
Identification Division.
Method-id. “createCheckingAccount”.
Data division.
Linkage section.
01 inAccountNumber pic S9(6) binary.
01 inInitialBalance pic S9(9) binary.
01 outCheckingAccount object reference CheckingAccount.
Copy JNI.
Procedure Division using by value inAccountNumber
inInitialBalance
returning outCheckingAccount.
Set address of JNIEnv to JNIEnvPtr
Set address of JNINativeInterface to JNIEnv
Invoke CheckingAccount New returning outCheckingAccount
Invoke outCheckingAccount “init”
using by value inAccountNumber
Invoke outCheckingAccount “credit”
using by value inInitialBalance
Add 1 to NumberOfCheckingAccounts.
End method “createCheckingAccount”.
*
End Factory.
*
Identification division.
Object.
Data division.
Working-storage section.
01 CheckFee pic S9(9) value 1.
Procedure Division.
*
* processCheck method to get the check amount and payee,
* add the check fee, and invoke inherited methods debit
* to debit the payer and credit to credit the payee:
Identification Division.
Method-id. “processCheck”.
Data division.
Local-storage section.
01 amount pic S9(9) binary.
01 payee usage object reference Account.
Linkage section.
01 aCheck usage object reference Check.
Procedure Division using by value aCheck.
Invoke aCheck “getAmount” returning amount
Invoke aCheck “getPayee” returning payee
Invoke payee “credit” using by value amount
Add checkFee to amount
Invoke self “debit” using by value amount.
End method “processCheck”.
*
* print method override to display account status:
Identification Division.
Method-id. “print”.
Data division.
Local-storage section.
01 printableFee pic $$,$$$,$$9.
Procedure Division.
Invoke super “print”
Move CheckFee to printableFee
Display “ Check fee: ” printableFee.
End method “print”.
*
End Object.
*
End class CheckingAccount.
/**
* A Java class for check information
*/
public class Check {
private CheckingAccount payer;
private Account payee;
private int amount;
public Check(CheckingAccount inPayer, Account inPayee, int inAmount) {
payer=inPayer;
payee=inPayee;
amount=inAmount;
}
public int getAmount() {
return amount;
}
public Account getPayee() {
return payee;
}
}
cbl thread,pgmname(longmixed)
Identification division.
Program-id. “TestAccounts” recursive.
Environment division.
Configuration section.
Repository.
Class Account is “Account”
Class CheckingAccount is “CheckingAccount”
Class Check is “Check”.
Data Division.
* Working data is declared in Local-storage
* so that each thread has its own copy:
Local-storage section.
01 anAccount usage object reference Account.
01 aCheckingAccount usage object reference CheckingAccount.
01 aCheck usage object reference Check.
01 payee usage object reference Account.
*
Procedure division.
Test-Account-section.
Display “Test Account class”
* Create account 123456 with 0 balance:
Invoke Account “createAccount”
using by value 123456
returning anAccount
* Deposit 500 to the account:
Invoke anAccount “credit” using by value 500
Invoke anAccount “print”
Display space
*
Display “Test CheckingAccount class”
* Create checking account 777777 with balance of 300:
Invoke CheckingAccount “createCheckingAccount”
using by value 777777 300
returning aCheckingAccount
* Set account 123456 as the payee:
Set payee to anAccount
* Initialize check for 125 to be paid by account 777777 to payee:
Invoke Check New
using by value aCheckingAccount, payee, 125
returning aCheck
* Debit the payer, and credit the payee:
Invoke aCheckingAccount “processCheck”
using by value aCheck
Invoke aCheckingAccount “print”
Invoke anAccount “print”
*
Stop Run.
End program “TestAccounts”.
Test Account class Account: 123456 Balance: $500 Test CheckingAccount class Account: 777777 Balance: $174 Check fee: $1 Account: 123456 Balance: $625
関連タスク
クラスのインスタンスの作成および初期化
ファクトリー・メソッドの定義
ファクトリー・メソッドまたは静的メソッドの呼び出し
オブジェクト指向アプリケーションのコンパイル、リンク、および実行