我正在尝试使用 JUnit、Mockito 和 PowerMock 验证对 java.sql.DriverManager.getConnection 的调用。

这是我的测试用例:

@RunWith(PowerMockRunner.class)
@PrepareForTest(DriverManager.class)
public class MySQLDatabaseConnectionFactoryTest {

    private ConfigurationService configurationService;
    private MySQLDatabaseConnectionFactory reference;

    @Before
    public void setUp() throws Exception {
        this.reference = new MySQLDatabaseConnectionFactory();
    }

    @Test
    public void testGetConnection() throws SQLException {
//      setup
        Connection connection = mock(Connection.class);

        PowerMockito.mockStatic(DriverManager.class);

        when(DriverManager.getConnection(anyString(), anyString(), anyString())).thenReturn(connection);

//      run
        this.reference.getConnection();

//      verify
        PowerMockito.verifyStatic();
        DriverManager.getConnection("jdbc:mysql://myhost:1111/database", "username", "password");
    }

}

下面是测试代码:

public class MySQLDatabaseConnectionFactory implements
        DatabaseConnectionFactory {

    @Override
    public Connection getConnection(IApplicationInstance appInstance) {         
        try {
            return DriverManager.getConnection(String.format("jdbc:mysql://%s:%d/%s", 
                    MYSQL_HOST, MYSQL_PORT, MYSQL_DATABASE), MYSQL_USERNAME, MYSQL_PASSWORD);
        } catch (SQLException e) {
            throw new RuntimeException(e);
        }
    }
}

有趣的是，这段代码失败并出现 java.sql.SQLException:

java.lang.RuntimeException: java.sql.SQLException: No suitable driver found for jdbc:mysql://myhost:1111/database

现在，我可以轻松地确保我的 SQL 驱动程序(在本例中为 MySQL)在测试时加载，但为什么没有完全模拟静态方法而没有副作用？

更新:

我最好隔离问题。我在我的测试用例中添加了一个测试方法，它尝试从 DriverManager 获取连接:

@Test
public void testSomething() {
    Connection conn = mock(Connection.class);
    mockStatic(DriverManager.class);
    when(DriverManager.getConnection(anyString())).thenReturn(conn);
    Connection c = DriverManager.getConnection("whut");
    verifyStatic();
    DriverManager.getConnection("whut");
}

这个测试实际上通过了，而另一个测试仍然失败。 PowerMock 似乎没有模拟对 MySQLDatabaseConnectionFactory 内部类的引用。我该如何解决这个问题？

最佳答案

将您的 @PrepareForTest 注释值更改为 MySQLDatabaseConnectionFactory.class 将解决此问题。

This annotation tells PowerMock to prepare certain classes for testing. Classes needed to be defined using this annotation are typically those that needs to be byte-code manipulated. This includes final classes, classes with final, private, static.

在这种情况下，PowerMockito 必须用模拟代码替换对静态方法 DriverManager.getConnection 的调用。这是通过使用字节码操作来完成的。

完整代码

@RunWith(PowerMockRunner.class)
@PrepareForTest(MySQLDatabaseConnectionFactory.class)
public class MySQLDatabaseConnectionFactoryTest {

    private MySQLDatabaseConnectionFactory reference;

    @Before
    public void setUp() throws Exception {
        reference = new MySQLDatabaseConnectionFactory();
    }

    @Test
    public void testGetConnection() throws SQLException {

        // given
        PowerMockito.mockStatic(DriverManager.class);
        BDDMockito.given(DriverManager.getConnection(anyString(), anyString(), anyString()))
             .willReturn(mock(Connection.class));

        // when
        reference.getConnection();

        // then
        PowerMockito.verifyStatic();
        DriverManager.getConnection("jdbc:mysql://myhost:1111/database", "username", "password");
    }
}

感谢 @Szpak帮助我解决这个问题!

关于java - 使用 PowerMock 和 Mockito 模拟静态方法，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/21128690/