注冊如何使用Mockito測試匿名類內部的方法調用

Question

1.這是我的代碼，我想用mock或powermockito進行單元測試：

public class CarrierGroupDAO {
    @Autowired
    protected JdbcTemplate jdbcTemplate;

    public CarrierGroupDAO() {  }

    public Map<Long, String> getAllCarrierGroups() {
        String sql = "select t.carrier_group_id, t.updated_by from  pv_carrier_group t where t.status = 'Q'";
        return jdbcTemplate.execute(sql, new CallableStatementCallback<Map<Long, String>>() {
            @Override
            public Map<Long, String> doInCallableStatement(CallableStatement cs)
                    throws SQLException, DataAccessException {
                ResultSet resultSet = cs.executeQuery();
                Map<Long, String> carrierGroups = new HashMap<>();
                while (resultSet.next()) {
                    carrierGroups.put(resultSet.getLong("carrier_group_id"), resultSet.getString("updated_by"));
                }
                return carrierGroups;
            }
        });
    }
}

2.按照我的測試代碼：

    @Test
    public void testGetAllCarrierGroups() {
        CarrierGroupDAO carrierGroupDAO=new CarrierGroupDAO();

        CallableStatement cs=PowerMockito.mock(CallableStatement.class);
        JdbcTemplate jdbcTemplate=PowerMockito.mock(JdbcTemplate.class);
        PowerMockito.mock(JdbcTemplate.class);
        PowerMockito.when(jdbcTemplate.execute(Mockito.any(String.class),Mockito.any(CallableStatementCallback.class))).thenAnswer(new Answer<Object>() {
            @Override
            public Object answer(InvocationOnMock invocation) throws Throwable {
                Object[] args=invocation.getArguments();
                System.out.println(args.length);
                TransactionCallback arg = (TransactionCallback)args[1];
                return ((CallableStatementCallback) arg).doInCallableStatement(cs);
            }
        });

        ResultSet resultSet =PowerMockito.mock(ResultSet.class);
        try {
            PowerMockito.when(cs.executeQuery()).thenReturn(resultSet);
            PowerMockito.when(resultSet.next()).thenReturn(true).thenReturn(false);
            PowerMockito.when(resultSet.getLong(Mockito.any(String.class))).thenReturn((long)1);
            PowerMockito.when(resultSet.getString(Mockito.any(String.class))).thenReturn("haha");
            carrierGroupDAO.getAllCarrierGroups();
            Mockito.verify(cs).executeQuery();
        } catch (SQLException e) {
            e.printStackTrace();
        }       
    }

錯誤信息：

    java.lang.NullPointerException
    at CarrierGroupDAO.getAllCarrierGroups(CarrierGroupDAO.java:27)
    at CarrierGroupDAOTest.testGetAllCarrierGroups(CarrierGroupDAOTest.java:47)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:45)
    at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:15)
    at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:42)
    at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:20)
    at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:263)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:68)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:47)
    at org.junit.runners.ParentRunner$3.run(ParentRunner.java:231)
    at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:60)
    at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:229)
    at org.junit.runners.ParentRunner.access$000(ParentRunner.java:50)
    at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:222)
    at org.junit.runners.ParentRunner.run(ParentRunner.java:300)
    at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:86)
    at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:459)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:678)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:382)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:192)

如果您有解決此問題的想法，請問我，謝謝！

Answer 1

這里有一些問題：

1. 您正在模擬JdbcTemplate但沒有將此模擬的實例注入CarrierGroupDAO （這會導致NullPointerException ）。
2. 您使用的是PowerMockito ，其中Mockito就足夠了。
3. 您的Answer嘗試將secopnd參數轉換為jdbcTemplate.execute(...)到TransactionCallback 。

它們很容易通過以下方式解決：

• 將JdbcTemplate注入CarrierGroupDAO

   public class CarrierGroupDAO { private JdbcTemplate jdbcTemplate; @Autowired public CarrierGroupDAO(JdbcTemplate jdbcTemplate) { this.jdbcTemplate = jdbcTemplate; } public Map<Long, String> getAllCarrierGroups() { String sql = "select t.carrier_group_id, t.updated_by from pv_carrier_group t where t.status = 'Q'"; return jdbcTemplate.execute(sql, new CallableStatementCallback<Map<Long, String>>() { @Override public Map<Long, String> doInCallableStatement(CallableStatement cs) throws SQLException, DataAccessException { ResultSet resultSet = cs.executeQuery(); Map<Long, String> carrierGroups = new HashMap<>(); while (resultSet.next()) { carrierGroups.put(resultSet.getLong("carrier_group_id"), resultSet.getString("updated_by")); } return carrierGroups; } }); } } 

• Mockito測試用例以使用Mockito並更改Answer實現：

   @Test public void testGetAllCarrierGroups() throws SQLException { JdbcTemplate jdbcTemplate = Mockito.mock(JdbcTemplate.class); CarrierGroupDAO carrierGroupDAO = new CarrierGroupDAO(jdbcTemplate); CallableStatement cs = Mockito.mock(CallableStatement.class); Mockito.when(jdbcTemplate.execute(Mockito.any(String.class), Mockito.any(CallableStatementCallback.class))) .thenAnswer(new Answer<Object>() { @Override public Object answer(InvocationOnMock invocation) throws Throwable { Object[] args = invocation.getArguments(); System.out.println(args.length); CallableStatementCallback arg = (CallableStatementCallback) args[1]; return arg.doInCallableStatement(cs); } }); ResultSet resultSet = Mockito.mock(ResultSet.class); Mockito.when(cs.executeQuery()).thenReturn(resultSet); // expecting one entry in the resultset Mockito.when(resultSet.next()).thenReturn(true).thenReturn(false); long expectedKey = 1; String expectedValue = "haha"; Mockito.when(resultSet.getLong(Mockito.any(String.class))).thenReturn(expectedKey); Mockito.when(resultSet.getString(Mockito.any(String.class))).thenReturn(expectedValue); Map<Long, String> allCarrierGroups = carrierGroupDAO.getAllCarrierGroups(); Assert.assertEquals(1, allCarrierGroups.size()); Assert.assertTrue(allCarrierGroups.containsKey(expectedKey)); Assert.assertEquals(expectedValue, allCarrierGroups.get(expectedKey)); }