Java 在JUnit测试中使用变量

我想先保存VO并获取其Id（主键），然后根据Id执行get和delete操作

我的代码

@FixMethodOrder(MethodSorters.NAME_ASCENDING)
public class TransactionDAOImplTest {

    TransactionDAOImpl daoImpl = new TransactionDAOImpl();

    public long Id; 
    String transactionId = "1468597863";
    String uniqueKey = "124587878";

//  @Ignore
    @Test
    public void test1_savetransaction() {
        transactionVO transactionVO = new TransactionVO();
        transactionVO.setTransactionId(transactionId);
        transactionVO.setUniqueKey(uniqueKey);
        transactionVO.setCreationDate(Calendar.getInstance());
        transactionVO vo = daoImpl.saveTransaction(transactionVO);
        Id = vo.getId(); // Here Id is setting to some value like 775
        assertEquals(transactionId, vo.getTransactionId());
    }

//  @Ignore
    @Test
    public void test2_findTransactionEvent() {
        transactionVO vo = daoImpl.findTransaction(Id); // Here Id is reseting to 0 it should be 775, so not able to get
        assertEquals(transactionId, vo.getTransactionId());
    }

//  @Ignore
    @Test
    public void test3_deletetransaction() {
        int deletedCount = daoImpl.deleteTransactionById(Id); // Here also Id reseting to 0 it should be 775, so not able to delete
        assertTrue(deletedCount > 0);
    }

但当我设置Id并在其他方法中使用它时，它会重置为0

---

如何在所有JUnit测试方法中使用变量（例如Id）？

将Id设置为静态，以便每个jvm只有一个副本

static public long Id;

将设置Id添加到，使其在所有方法中都可用（需要是静态的）

public static long Id;
@BeforeClass public static void onlyOnce() {
    transactionVO transactionVO = new TransactionVO();
    transactionVO.setTransactionId(transactionId);
    transactionVO.setUniqueKey(uniqueKey);
    transactionVO.setCreationDate(Calendar.getInstance());
    transactionVO vo = daoImpl.saveTransaction(transactionVO);
    Id = vo.getId(); // Here Id is setting to some value like 775
}