Java 编程：使用 List 接口优化 Customer 和 Bank 类

package step3;

import java.util.ArrayList; import java.util.List;

public class Customer extends Object { private String firstName; private String lastName; '******** Begin *' private List accounts = new ArrayList<>(10); ' End *********'

public Customer(String ln, String sn) {
	this.lastName = ln;
	this.firstName = sn;
    '******** Begin *********'
    // accounts = new ArrayList<>(10);
    '******** End *********'
}
// getter方法
public String getFirstName() {
	return firstName;
}

public String getLastName() {
	return lastName;
}

public int getNumberOfAccounts() {
	'******** Begin *********'
    return accounts.size();
    '******** End *********'
}

public String toString() {
	return "[" + lastName + ", " + firstName + "]";
}

// 业务逻辑方法：
public void addAccount(double amount) {
	'******** Begin *********'
    accounts.add(new Account(amount));
    '******** End *********'
}

public void addAccount(Account account) {
	'******** Begin *********'
    accounts.add(account);
    '******** End *********'	}

// 查看某一个账户的信息
public Account getAccount(int index) {
	'******** Begin *********'
    return accounts.get(index);
    '******** End *********'	}

} package step3;

import java.util.ArrayList; import java.util.List;

public class Bank { // 静态成员变量及初始化 '******** Begin *' private static List customers = new ArrayList<>(10); ' End *********'

public static int getNumberOfCustomers() {
    '******** Begin *********'
    return customers.size();
    '******** End *********'
}

public static void addCustomer(String ln, String fn) {
    '******** Begin *********'
    customers.add(new Customer(ln, fn));
    '******** End *********'
}

public static Customer getCustomer(int index) {
    '******** Begin *********'
    return customers.get(index);
    '******** End *********'
}

}