public String getOrderNumber() { String orderNumber = ""; String currentDate = DateUtil.getCurrentDate(); Condition condition=new Condition(TbDutyInspectClass.class); condition.createCriteria().andCondition("is_delete=0 ").andCondition("to_char(CREATE_DATE,'yyyy-MM-dd')='" + currentDate + "'"); condition.setOrderByClause("id desc"); List<TbDutyInspectClass> list = mapper.selectByExample(condition); if(list.isEmpty()){ orderNumber = currentDate.replaceAll("-","") + "01"; }else { orderNumber = currentDate.replaceAll("-","") + (list.size()+1); } return orderNumber; }怎么将自增数补成两位数
时间: 2024-02-17 20:59:44 浏览: 23
可以使用 String.format() 方法将自增数格式化成两位数的字符串,例如:
```
orderNumber = currentDate.replaceAll("-","") + String.format("%02d", list.size()+1);
```
这里使用了 %02d,表示格式化为两位数的十进制整数,不足两位时前面补0。
相关问题
package shixun; import java.util.ArrayList; import java.util.List; public class OrderManager { private List<Order> orders = new ArrayList<>(); public void addOrder(Order order) { orders.add(order); } public void deleteOrder(int orderNumber) { for (Order order : orders) { if (order.getOrderNumber() == orderNumber) { orders.remove(order); break; } } } public void updateOrder(int orderNumber, String status) { for (Order order : orders) { if (order.getOrderNumber() == orderNumber) { order.setStatus(status); break; } } } public Order queryOrder(int orderNumber) { for (Order order : orders) { if (order.getOrderNumber() == orderNumber) { return order; } } return null; } public List<Order> getAllOrders() { return orders; } }为什么报错
没有给出具体的错误信息,因此我无法确定错误的原因。但是,这段代码存在一些潜在的问题:
1. 在遍历列表时,使用了 orders.remove(order) 的方式来删除元素,但是在遍历时修改列表会导致ConcurrentModificationException异常;
2. 在查询订单时,如果没有找到对应的订单,会返回null,但是调用方可能没有处理null值的情况,这可能会导致NullPointerException异常。
public class Order { private int orderNumber; private String serviceType; private double price; private String status; public Order(int orderNumber, String serviceType, double price, String status) { this.orderNumber = orderNumber; this.serviceType = serviceType; this.price = price; this.status = status; } public int getOrderNumber() { return orderNumber; } public String getServiceType() { return serviceType; } public double getPrice() { return price; } public String getStatus() { return status; } @Override public String toString() { return "Order{" + "orderNumber=" + orderNumber + ", serviceType='" + serviceType + '\'' + ", price=" + price + ", status='" + status + '\'' + '}'; } public static void main(String[] args) { Order order = new Order(1, "Service A", 100.0, "New"); System.out.println(order); } }怎么接着完成这个系统
要完成这个系统,您需要确定系统的功能和需求。一般而言,一个订单管理系统需要以下基本功能:
1. 添加订单
2. 修改订单
3. 删除订单
4. 查询订单
5. 显示所有订单
在这个基础上,您可以根据实际需求进行扩展,比如:
1. 导出订单
2. 订单统计
3. 订单归档
4. 等等
接下来,您可以根据需要实现一个订单管理类,用于管理和操作订单,具体代码可以参考下面的示例:
```java
import java.util.ArrayList;
import java.util.List;
public class OrderManager {
private List<Order> orders = new ArrayList<>();
public void addOrder(Order order) {
orders.add(order);
}
public void deleteOrder(int orderNumber) {
for (Order order : orders) {
if (order.getOrderNumber() == orderNumber) {
orders.remove(order);
break;
}
}
}
public void updateOrder(int orderNumber, String status) {
for (Order order : orders) {
if (order.getOrderNumber() == orderNumber) {
order.setStatus(status);
break;
}
}
}
public Order queryOrder(int orderNumber) {
for (Order order : orders) {
if (order.getOrderNumber() == orderNumber) {
return order;
}
}
return null;
}
public List<Order> getAllOrders() {
return orders;
}
}
```
在此基础上,您可以编写一个简单的控制台程序来测试订单管理系统的功能,比如:
```java
public class OrderSystem {
public static void main(String[] args) {
OrderManager orderManager = new OrderManager();
Order order1 = new Order(1, "Service A", 100.0, "New");
Order order2 = new Order(2, "Service B", 200.0, "New");
Order order3 = new Order(3, "Service C", 300.0, "New");
orderManager.addOrder(order1);
orderManager.addOrder(order2);
orderManager.addOrder(order3);
System.out.println("All orders:");
for (Order order : orderManager.getAllOrders()) {
System.out.println(order);
}
orderManager.deleteOrder(2);
System.out.println("All orders after deleting order 2:");
for (Order order : orderManager.getAllOrders()) {
System.out.println(order);
}
orderManager.updateOrder(3, "Completed");
System.out.println("Order 3 after updating status to completed:");
System.out.println(orderManager.queryOrder(3));
}
}
```
这样,您就可以创建一个简单的订单管理系统,并且可以根据需要进行扩展和优化。