初学者Java按顺序递增设置变量并重置计数

我的类方法有一些小问题，我要按顺序递增。基本上，我的类可以编译，有一个测试类，当我运行测试仪来获取测试结果时，我没有得到想要的输出，随后是错误消息，我将在下面提供。

我的问题是，当我创建一个对象时，它以前缀+计数器开始，但不立即对其进行递增，我希望它是这样，以便它立即将创建的第一个对象递增至1001，依此类推。这些错误消息使我困惑，期望值与期望输出完全不同。

我设置了前缀和一个从1000开始的计数器。

 public static final String TICKET_PREFIX = "VAN";
    public static int counter = 1000;

public ParkingTicket(){
     ticketNumber = generateTicketNumber();
    }
        }
private String generateTicketNumber(){

ticketNumber = TICKET_PREFIX + counter++;
return ticketNumber;

}

这是测试类代码块中捕获错误的代码

@Test
    public void testConstructorTicketNumberSEquential() {
        ParkingTicket.resetCounter();
        ParkingTicket ticket = new ParkingTicket("Adam White","VAN5225", "1A2B3C",20 ); 
        ParkingTicket ticket2 = new ParkingTicket("Adam White","VAN5225", "1A2B3C",20 ); 
        ParkingTicket ticket3 = new ParkingTicket("Adam White","VAN5225", "1A2B3C",20 ); 
        assertEquals("VAN1001",ticket.getTicketNumber());
        assertEquals("VAN1003", ticket3.getTicketNumber());

这是来自测试仪的错误消息

testConstructorTicketNumberSEquential
---
org.junit.ComparisonFailure: expected:<VAN100[1]> but was:<VAN100[7]>
    at org.junit.Assert.assertEquals(Assert.java:115)
    at org.junit.Assert.assertEquals(Assert.java:144)
    at ParkingTicketTest.testConstructorTicketNumberSEquential(ParkingTicketTest.java:238)

我也有一种方法来重置计数器。我尝试仅返回计数器值，但仍然出现错误

public static int resetCounter(){
        int reset = counter;
        return reset;
    }

测试重置计数器

  @Test
    public void  testResetCounter() {
        ParkingTicket.resetCounter();
        assertEquals(1000,ParkingTicket.counter);
}

测试运行错误消息

testResetCounter
---
java.lang.AssertionError: expected:<1000> but was:<1005>
    at org.junit.Assert.fail(Assert.java:88)
    at org.junit.Assert.failNotEquals(Assert.java:743)
    at org.junit.Assert.assertEquals(Assert.java:118)
    at org.junit.Assert.assertEquals(Assert.java:555)
    at org.junit.Assert.assertEquals(Assert.java:542)
    at ParkingTicketTest.testResetCounter(ParkingTicketTest.java:264)

问题来源：Stack Overflow