如何在两个测试类之间共享外部资源

Question

我正在努力理解使用ExternalResource的好处。 文档和其他帖子（Junit @Rule如何工作？）都提到了能够在类内的测试之间共享代码和/或在测试类之间共享代码。

我正在尝试在功能/集成测试中使用 ExternalResource 作为数据库连接，但我不明白如何在类之间共享该连接。事实上，在这种情况下，我并没有真正看到比@Before/@After的好处。 我是否错误地使用了它或我错过了什么？

public class some_IntegrationTest {
    private static String id;
    Connection connection = null;
    //...
    @Rule
    public ExternalResource DBConnectionResource = new ExternalResource() {
        @Override
        protected void before() throws SQLException {
            connection = DbUtil.openConnection();
        }
        @Override
        protected void after() {
            DbUtil.closeConnection(connection);
        }
    };
    @BeforeClass
    public static void setUpClass() throws SQLException {
        System.out.println("@BeforeClass setUpClass");
        cleanup(id);
    }
    //I want to do something like this
    @Test
    public void test01() {
        cleanupData(connection, id);
        // do stuff...
    }
    @Test
    public void test02() {
        cleanupTnxLog(connection, id);
        // do stuff...
    }
    //...

    private static void cleanup(String id) throws SQLException {
        LOGGER.info("Cleaning up records");
        Connection connection = null;
        try {
            connection = DbUtil.openConnection();
            cleanupData(connection, id);
            cleanupTnxLog(connection, id);
        } finally {
            DbUtil.closeConnection(connection);
        }
    }
    private static void cleanupData(Connection connection, String id)
        throws SQLException {
        dao1.delete(connection, id);
    }
    private static void cleanupTnxLog(Connection connection, String id)
        throws SQLException {
        dao2.delete(connection, id);
    }
}

Answer 1

我会做这样的事情：

public class DbConnectionRessource extends ExternalRessource {
    private Connection connection;
    @Override
    protected void before() throws SQLException {
        connection = DbUtil.openConnection();
    }
    @Override
    protected void after() {
        DbUtil.closeConnection(connection);
    }
    public Connection getConnection() {
        return connection;
    }
}

然后在测试中使用它，如下所示：

public class SomeIntegrationTest {
    @Rule
    public DbConnectionRessource dbConnectionResource = new DbConnectionRessource();
    // ...
    @Test
    public void test01() {
        cleanupData(dbConnectionResource.getConnection(), id);
        // do stuff...
    }
    // ...
}

[未测试]