ModulesTest.java 文件源码

/**
 * Basic test of the public static provider method. BananaScriptEngine
 * defines a provider method that returns the same instance.
 */
@Test
public void testSingleton() {
    Optional<Provider<ScriptEngineFactory>> oprovider
        = ServiceLoader.load(ScriptEngineFactory.class)
            .stream()
            .filter(p -> p.type().getName().equals("org.banana.BananaScriptEngineFactory"))
            .findFirst();
    assertTrue(oprovider.isPresent());
    Provider<ScriptEngineFactory> provider = oprovider.get();

    // invoke Provider::get twice
    ScriptEngineFactory factory1 = provider.get();
    ScriptEngineFactory factory2 = provider.get();
    assertTrue(factory1 == factory2);
}