GAE：從JUnit測試創建一個實體對象

Question

我的一個GAE類是建立一個[數據存儲實體] [1]從HTML文件：

Key parent = KeyFactory.createKey("movies", "movies"); 
Entity movie = new Entity("movie",System.currentTimeMillis(), parent); 
setIfNotEmpty(movie, "director", Jsoup.parse(Html).select("td#f3").text()); 
setIfNotEmpty(movie, "year",  Jsoup.parse(Html).select("td#f17").text()); 
.... 

當我試圖調用的這個方法JUnit測試，拋出以下異常：

java.lang.NullPointerException: No API environment is registered for this thread. 
    at com.google.appengine.api.datastore.DatastoreApiHelper.getCurrentAppId(DatastoreApiHelper.java:80) 
    at com.google.appengine.api.datastore.DatastoreApiHelper.getCurrentAppIdNamespace(DatastoreApiHelper.java:90) 
    at com.google.appengine.api.datastore.Key.<init>(Key.java:97) 
    at com.google.appengine.api.datastore.Key.<init>(Key.java:87) 
    at com.google.appengine.api.datastore.KeyFactory.createKey(KeyFactory.java:85) 
    at com.google.appengine.api.datastore.KeyFactory.createKey(KeyFactory.java:78) 
    at com.google.appengine.api.datastore.KeyFactory.createKey(KeyFactory.java:66) 
    at cinemasderot.Movie.parseMovieHtml(Movie.java:21) 
    at tests.TestParsing.testAddition(TestParsing.java:24) 
    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:45) 
    at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:15) 
    at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:42) 
    ..... 

該問題似乎是在我的代碼示例的第一行中創建密鑰。

如何使用Junit測試中的父鍵創建實體？

Answer 1

請閱讀：https://developers.google.com/appengine/docs/java/tools/localunittesting

總之，你需要的是這樣的：

private final LocalServiceTestHelper helper = 
    new LocalServiceTestHelper(new LocalDatastoreServiceTestConfig()); 

@Before 
public void setUp() { 
    helper.setUp(); 
} 

@After 
public void tearDown() { 
    helper.tearDown(); 
}