java实现信用卡查询
时间: 2023-11-18 09:18:59 浏览: 37
抱歉,作为AI语言模型,我无法提供完整的Java程序,但是我可以提供一些思路和可能会用到的Java代码片段。
1. 设计一个CreditCard类,包含以下属性:卡号、过期日期、持卡人姓名、信用额度、剩余额度等。可以使用以下代码片段创建CreditCard类:
public class CreditCard {
private String cardNumber;
private String expirationDate;
private String cardHolderName;
private double creditLimit;
private double remainingCredit;
// 构造方法
public CreditCard(String cardNumber, String expirationDate, String cardHolderName, double creditLimit) {
this.cardNumber = cardNumber;
this.expirationDate = expirationDate;
this.cardHolderName = cardHolderName;
this.creditLimit = creditLimit;
this.remainingCredit = creditLimit;
}
// getter 和 setter 方法
// ...
}
2. 创建一个CreditCardDAO类,用于从数据库中获取信用卡信息。可以使用以下代码片段作为参考:
public class CreditCardDAO {
// 数据库连接信息
private static final String DB_URL = "jdbc:mysql://localhost:3306/credit_cards";
private static final String DB_USER = "root";
private static final String DB_PASSWORD = "password";
// 获取信用卡信息
public CreditCard getCreditCard(String cardNumber) {
Connection connection = null;
PreparedStatement statement = null;
ResultSet rs = null;
CreditCard creditCard = null;
try {
// 创建数据库连接
connection = DriverManager.getConnection(DB_URL, DB_USER, DB_PASSWORD);
// 执行查询语句
String sql = "SELECT * FROM credit_cards WHERE card_number = ?";
statement = connection.prepareStatement(sql);
statement.setString(1, cardNumber);
rs = statement.executeQuery();
// 处理结果集
if (rs.next()) {
String expirationDate = rs.getString("expiration_date");
String cardHolderName = rs.getString("card_holder_name");
double creditLimit = rs.getDouble("credit_limit");
double remainingCredit = rs.getDouble("remaining_credit");
creditCard = new CreditCard(cardNumber, expirationDate, cardHolderName, creditLimit);
creditCard.setRemainingCredit(remainingCredit);
}
} catch (SQLException e) {
e.printStackTrace();
} finally {
// 关闭数据库连接
try {
if (rs != null) rs.close();
if (statement != null) statement.close();
if (connection != null) connection.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
return creditCard;
}
}
3. 在程序中使用CreditCardDAO类获取信用卡信息,并进行查询操作。可以使用以下代码片段作为参考:
public class CreditCardQuery {
public static void main(String[] args) {
CreditCardDAO dao = new CreditCardDAO();
CreditCard creditCard = dao.getCreditCard("1234567890123456");
if (creditCard != null) {
System.out.println("Card Number: " + creditCard.getCardNumber());
System.out.println("Expiration Date: " + creditCard.getExpirationDate());
System.out.println("Card Holder Name: " + creditCard.getCardHolderName());
System.out.println("Credit Limit: " + creditCard.getCreditLimit());
System.out.println("Remaining Credit: " + creditCard.getRemainingCredit());
} else {
System.out.println("Credit card not found.");
}
}
}
上述代码片段中,CreditCardQuery类调用CreditCardDAO类的getCreditCard方法获取信用卡信息,并将结果输出到控制台。如果查询不到信用卡信息,程序会输出"Credit card not found."。