Question

我正在尝试为一个名为DriverManager.getConnection()的方法编写单元测试。我正在使用PowerMock 1.5和easymock。不知何故，Powermock无法模拟DriverManager并最终调用真正的DriverManager。这就是我的代码的样子： -

@Test
public void checkConnection() {
    try {
        String url = "jdbc:oracle:thin:@//myhost:1521/orcl";
        String password = "@55";
        String dbName = "Halloween";
        String username = "Dracula";

        PowerMock.mockStatic(DriverManager.class);

        Connection connection = EasyMock.createMock(Connection.class);
        List<Datasource> allDs = new ArrayList<Datasource>(2);
        Datasource d1 = new Datasource();
        d1.setUrl(url);
        allDs.add(d1);
        allDs.add(new Datasource());

        EasyMock.expect(hibernateTemplate.find("from Datasource ds where ds.dsName = ?", dbName)).andReturn(allDs);

        EasyMock.expect(DriverManager.getConnection(d1.getUrl(), username, password)).andReturn(connection);

        PowerMock.replay(DriverManager.class);
        EasyMock.replay(hibernateTemplate);

        Connection con = testee.authenticateUserForDatabase(dbName, username, password);
        Assert.assertNotNull(con);

        PowerMock.verify(DriverManager.class);
        EasyMock.verify(hibernateTemplate);
    } catch (Exception e) {
        Assert.fail(e.getMessage());
    }
}

我的班级代码如下所示： -

 @Override
public Connection getConnection(String dbName, String username, String password) {
    Connection connection = null;
    @SuppressWarnings("unchecked")
    List<Datasource> ds = hibernateTemplate.find("from Datasource ds where ds.dsName = ?", dbName);
    if (ds == null || ds.isEmpty()) {
        throw new ProviderException("Invalid datasource name [" + dbName + "]");
    }
    Datasource d = (Datasource) ds.get(0);
    int retryCount = 0;
    boolean connected = false;
    while (retryCount < 2 && !connected) {
        try {
            connection = DriverManager.getConnection(d.getUrl(), username, password);
            LOG.info("Connected successfully to [{}]", dbName);
            connected = true;
        } catch (SQLException e) {
            LOG.warn("Error: [{}] occured. Going to retry, attempt # [{}]", e.getMessage(), (retryCount + 1));
            retryCount++;
            connected = false;
        }
    }
    return connection;
}

Answer 1

您可以使用javax.sql.DataSource而不是使用DriverManager。

http://docs.oracle.com/javase/6/docs/api/javax/sql/DataSource.html

这样，您正在使用可以模拟的界面。目前大多数应用程序都使用DataSource接口，并且不像这样与DriverManager交互。

所以你的代码可以有一个api：

public class DataSourceFactory {
  public DataSource getDataSource( String url, String usr, String pwd);
}

如果您愿意，可以使用DriverManager实现真正的DataSource，然后模拟DataSourceFactory进行单元测试。

Answer 2

如果您无法模拟DriverManager.getConnection静态调用，可能的解决方法就是跳过它。

使用与静态方法相同的签名将静态调用提取到sut中受保护的方法。

protected Connection driverManagerGetConnection(String url, String user, String password){
  return DriverManager.getConnection(url, user, password);
}

现在，在您的测试中，使用您的sut的EasyMock to create a partial mock，嘲笑driverManagerGetConnection方法。

public void testFoo{

  // setup: sut
  YourSutClass sut = EasyMock.createMockBuilder(YourSutClass.class)
                 .addMockedMethod("driverManagerGetConnection").createMock();

  ...

  // setup: expectations
  EasyMock.expect(sut.driverManagerGetConnection()).andReturn(mockConnection);
  ...

  // exercise
  EasyMock.replay(sut, mockConnection);
  sut.whatever();

  // verify
  EasyMock.verify(sut, mockConnection);
}

使用这种方法，您未经测试的唯一一行是对静态方法的调用。

Java Mocking DriverManager

2 个答案: