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| Code Block | ||
|---|---|---|
| ||
package Account;
import User.*;
class AccountClass {
private UserClass uc; // uses a class defined in package User
protected synchronized void depositFunds(String username, double amount) {
// use a utility method of UserClass to check if username exists
if(uc.exists(username)) {
// deposit the amount
}
}
protected double getBalance(String accountNumber) { /* return the account balance */ }
}
package User;
import Account.*;
class UserClass extends AccountClass {
protected synchronized double getUserBalance(String accountNumber) {
// use a method of AccountClass to get the account balance
return getBalance(accountNumber);
}
public boolean exists(String username) { /* check whether user exists*/ }
}
|
Compliant Solution
TODO. Outline below. Do not use DRAFT.
| Code Block | ||
|---|---|---|
| ||
public interface BankApplication {
void depositFunds(BankApplication ba, String username, double amount);
double getBalance(String accountNumber);
double getUserBalance(String accountNumber);
boolean exists(String username);
}
class AccountClass {
public synchronized void depositFunds(BankApplication ba, String username, double amount) {
// use a utility method of UserClass to check if username exists
if(ba.exists(username)) {
// deposit the amount
}
}
public double getBalance(String accountNumber) { /* return the account balance */ return 1.0; }
}
class UserClass extends AccountClass implements BankApplication {
public synchronized double getUserBalance(String accountNumber) {
// use a method of AccountClass to get the account balance
return getBalance(accountNumber);
}
public boolean exists(String username) { /* check if user exists*/ return true; }
}
class BankOperations {
private BankApplication ba;
public BankOperations(BankApplication ba) {
this.ba = ba;
}
public void doUserActions() {
System.out.println(ba.exists("user"));
System.out.println(ba.getUserBalance("1111"));
}
public static void main(String[] args) {
AccountClass ac = new AccountClass();
ac.depositFunds(new UserClass(), "user", 1.0);
BankOperations bo = new BankOperations(new UserClass());
bo.doUserActions();
}
}
|
Risk Assessment
Acyclic dependencies between packages can lead to fragile builds. A security vulnerability in any package will easily percolate to several other packages.
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