尽管抛出预期的异常，但 JUnit 测试失败

Question

标题说，我正在测试一个DAO函数，我希望该函数抛出SQLException。当我运行测试时，我得到以下跟踪跟踪：

Jun 05, 2018 11:49:55 PM org.han.ica.oose.sneeuwklokje.database.admin.AdminDaoImpl getElections
SEVERE: Cant get elections. 
java.sql.SQLException
at org.han.ica.oose.sneeuwklokje.database.admin.AdminDaoImpl.getElections(AdminDaoImpl.java:29)
at org.han.ica.oose.sneeuwklokje.database.admin.AdminDaoImplTest.testGetElectionsWithException(AdminDaoImplTest.java:102)
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:50)
at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)
at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
at org.junit.internal.runners.statements.ExpectException.evaluate(ExpectException.java:19)
at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:26)
at org.junit.internal.runners.statements.RunAfters.evaluate(RunAfters.java:27)
at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:78)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:57)
at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:26)
at org.junit.internal.runners.statements.RunAfters.evaluate(RunAfters.java:27)
at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
at org.mockito.internal.runners.JUnit45AndHigherRunnerImpl.run(JUnit45AndHigherRunnerImpl.java:37)
at org.mockito.runners.MockitoJUnitRunner.run(MockitoJUnitRunner.java:62)
at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:68)
at com.intellij.rt.execution.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:47)
at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:242)
at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:70)

java.lang.AssertionError: Expected exception: java.sql.SQLException
at org.junit.internal.runners.statements.ExpectException.evaluate(ExpectException.java:32)
at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:26)
at org.junit.internal.runners.statements.RunAfters.evaluate(RunAfters.java:27)
at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:78)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:57)
at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:26)
at org.junit.internal.runners.statements.RunAfters.evaluate(RunAfters.java:27)
at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
at org.mockito.internal.runners.JUnit45AndHigherRunnerImpl.run(JUnit45AndHigherRunnerImpl.java:37)
at org.mockito.runners.MockitoJUnitRunner.run(MockitoJUnitRunner.java:62)
at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:68)
at com.intellij.rt.execution.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:47)
at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:242)
at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:70)

这是测试：

@Test(expected = SQLException.class)
public void testGetElectionsWithException() throws SQLException {
try {
when(mockConn.prepareStatement(anyString())).thenThrow(new SQLException());
adminDao.getElections('>');
} catch (SQLException e) {
//verify and assert
verify(mockConn, times(1)).prepareStatement(anyString());
verify(mockPreparedStmnt, times(0)).executeQuery();
verify(mockResultSet, times(0)).next();
verify(mockResultSet, times(0)).getInt("id");
verify(mockResultSet, times(0)).getString("name");
verify(mockResultSet, times(0)).getDate("startDate");
verify(mockResultSet, times(0)).getDate("endDate");
throw e;
}
}

这是DAO函数：

@Override
public ElectionListResponse getElections(char selector) {
ElectionListResponse electionListResponse = new ElectionListResponse();
String query = NamedQueries.GET_ELECTIONS_BEGIN + selector + NamedQueries.GET_ELECTIONS_END;
try {
con = sqlConnection.getConnection();
stmt = con.prepareStatement(query);
rs = stmt.executeQuery();
DateFormat df = new SimpleDateFormat("yyyy-MM-dd HH:mm");
while (rs.next()) {
Election election = new Election();
election.setElectionID(rs.getInt("id"));
election.setElectionName(rs.getString("name"));
election.setStartDate(df.format(rs.getDate("startDate")));
election.setEndDate(df.format(rs.getDate("endDate")));
electionListResponse.addElection(election);
}
return electionListResponse;
} catch (SQLException e) {
LOGGER.log(Level.SEVERE, "Cant get elections. ", e);
} finally {
closeConnection();
}
return null;
}

我似乎无法弄清楚为什么这个测试失败了。知道为什么会失败吗？如果可能的话，你能发布代码的实际测试方式吗？

Answer 1

您不会从getElections()中抛出任何异常。

修改代码以引发异常，如下所示，

修改后的代码：

try {
/* ... */
return electionListResponse;
} catch (SQLException e) {
LOGGER.log(Level.SEVERE, "Cant get elections. ", e);
throw e;
} finally {
closeConnection();
}
return null;

Answer 2

记录异常，但返回 null。所以测试永远不会看到异常