java - ProviderTestCase 子类的 setUp() 方法中的 NPE

Question

目前我的 ProviderTestCase2 中有以下 setUp() 方法。在调用 newResolverWithContentProviderFromSql() 之后，它会在 Android API 深处抛出一个 NPE。我做错了什么，我该如何解决？

public void setUp() throws IllegalAccessException, InstantiationException {
    this.resolver = newResolverWithContentProviderFromSql(this.getMockContext(),
            "test.", BaseballCardProvider.class,
            BaseballCardContract.AUTHORITY,
            BaseballCardSQLHelper.DATABASE_NAME,
            BaseballCardSQLHelper.SCHEMA_VERSION, CREATE_TABLE
                    + INSERT_DATA);
}

这是供引用的堆栈跟踪:

java.lang.NullPointerException  
at android.test.RenamingDelegatingContext.openOrCreateDatabase(RenamingDelegatingContext.java:146)  
at android.content.ContextWrapper.openOrCreateDatabase(ContextWrapper.java:215)  
at android.database.DatabaseUtils.createDbFromSqlStatements(DatabaseUtils.java:1315)  
at android.test.ProviderTestCase2.newResolverWithContentProviderFromSql(ProviderTestCase2.java:219)  
at bbct.android.common.provider.test.BaseballCardProviderTest.setUp(BaseballCardProviderTest.java:44)  
at android.test.AndroidTestRunner.runTest(AndroidTestRunner.java:190)  
at android.test.AndroidTestRunner.runTest(AndroidTestRunner.java:175)  
at android.test.InstrumentationTestRunner.onStart(InstrumentationTestRunner.java:555)  
at android.app.Instrumentation$InstrumentationThread.run(Instrumentation.java:1584)

Answer 1

由于您已经覆盖了 setUp() 但没有调用 super.setUp()，所以 TestCase 不完整，因为像 documentation说:

This framework is set up automatically by the base class' setUp() method. If you override this method, you must call the super method as the first statement in your override.