我正在尝试使用dbunit和junit。这些测试是不涉及数据库的基本junit测试。该类在到达那里之前就失败了。当从onSetup()调用IDatabaseTester方法时，它抛出NullPointerException而不是执行我期望的操作：删除数据库，从dataset.xml构建它。
为什么会出现空指针异常？
29 public class TestModifyDb
30 {
31
32 private IDatabaseTester dbtester;
33
34 @Before
35 public void setUp() throws Exception
36 {
37 dbtester = new JdbcDatabaseTester("com.mysql.jdbc.Driver",
38 "jdbc:mysql://localhost/cal",
39 "cal",
40 "cal");
41
42 IDataSet dataSet = new FlatXmlDataSetBuilder().build(
43 new FileInputStream("src/gps/tasks/task3663/dataset.xml"));
44
45 dbtester.onSetup();
46 }
47
48 @After
49 public void tearDown() throws Exception
50 {
51 dbtester.onTearDown();
52 }
53
54 @Test(expected=IndexOutOfBoundsException.class)
55 public void outOfBounds()
56 {
57 new ArrayList<Object>().get(1);
58 }
59
60 @Test (expected=IndexOutOfBoundsException.class)
61 public void elementAt()
62 {
63 int[] intArray = new int[10];
64 int i = intArray[20];
65 }
66
67 }
这是堆栈跟踪：
java.lang.NullPointerException
at org.dbunit.operation.DeleteAllOperation.execute(DeleteAllOperation.java:92)
at org.dbunit.operation.CompositeOperation.execute(CompositeOperation.java:79)
at org.dbunit.AbstractDatabaseTester.executeOperation(AbstractDatabaseTester.java:190)
at org.dbunit.AbstractDatabaseTester.onSetup(AbstractDatabaseTester.java:103)
at gps.tasks.task3663.TestModifyDb.setUp(TestModifyDb.java:45)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:44)
at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:15)
at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:41)
at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:27)
at org.junit.internal.runners.statements.RunAfters.evaluate(RunAfters.java:31)
at org.junit.runners.BlockJUnit4ClassRunner.runNotIgnored(BlockJUnit4ClassRunner.java:79)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:71)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:49)
at org.junit.runners.ParentRunner$3.run(ParentRunner.java:193)
at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:52)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:191)
at org.junit.runners.ParentRunner.access$000(ParentRunner.java:42)
at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:184)
at org.junit.runners.ParentRunner.run(ParentRunner.java:236)
at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:50)
at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:467)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:683)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:390)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:197)
最佳答案
我怀疑您只是错过了这一行：
dbTester.setDataSet(dataSet);
（在初始化
dataSet之后，但在调用onSetup之前。）目前，您在创建
dataSet后不对其进行任何操作...关于java - dbunit为onSetup()抛出NullPointerException，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/10626698/