PrivateConstructorTest.java 文件源码

@Test
public void assertExistsPrivateCtor() {
    reflections.getSubTypesOf(Object.class).stream()
        .filter(clazz -> !clazz.isAnnotationPresent(Configuration.class))
        .filter(clazz -> !clazz.isAnnotationPresent(Component.class))
        .filter(clazz -> !clazz.isAnnotationPresent(SpringBootApplication.class))
        .filter(clazz -> !clazz.getName().endsWith("Test"))
        .filter(clazz -> !clazz.isInterface())
        .filter(clazz ->
            Arrays.stream(clazz.getDeclaredFields())
                .allMatch(field -> Modifier.isStatic(field.getModifiers())))
        .forEach(clazz -> {
            System.out.println("Expecting class "+clazz.getName()+" to :");
            System.out.print("\t-> be final ");
            assertThat(clazz).isFinal();
            System.out.println("[*]");
            System.out.print("\t-> have exactly one constructor ");
            Constructor<?>[] constructors = clazz.getDeclaredConstructors();
            assertThat(constructors).hasSize(1);
            System.out.println("[*]");
            System.out.print("\t-> and that this constructor is private ");
            assertThat(Modifier.isPrivate(constructors[0].getModifiers()));
            System.out.println("[*]");
        });
}