用Google Guice命名“Singleton”

Question

我尝试实现'@Named'注入，但我不想预定义@Named实例（我在最后有一个例子，它实际上正在工作......但不是我想要的方式 - 因为我预定义名字）

提供代码示例比解释我的意思更容易。

public class NamedSingletonExample {
    private static Map<String, DoubleProperty> dMap = new HashMap<String, DoubleProperty>();

    public static DoubleProperty getNamedDoubleProperty(String name) {
        DoubleProperty d = dMap.get(name);
        if (d == null) {
            d = new SimpleDoubleProperty();
            dMap.put(name, d);
        }
        return d;
    }

    @Test
    public void testNamedSingleton() {
        System.out.println("test()");
        DoubleProperty d0 = getNamedDoubleProperty("d0");
        DoubleProperty d1 = getNamedDoubleProperty("d1");
        DoubleProperty d0_2 = getNamedDoubleProperty("d0");
        d0.set(1);
        d1.set(2);
        d0_2.set(4);

        System.out.println("expected: false & actual -> " + (d0.get() == d1.get()));
        System.out.println("expected: true  & actual -> " + (d0.get() == d0_2.get()));
        System.out.println("expected: true  & actual -> " + (d0 == d0_2));
    }
}

这是我期望它使用guice

的方式

public class NamedSingletonConsumer {

    @Inject
    public NamedSingletonConsumer(//
            @Named("d0") DoubleProperty d0, //
            @Named("d1") DoubleProperty d1, //
            @Named("d0_2") DoubleProperty d0_2//
    ) {
        // ...
    }
}

我在StackOverflow上阅读了其他问题的大量内容并使用了谷歌（包括guice doc），但未能找到相关示例。

现在是“工作”的例子：

public class AllInOneExample {

    public AllInOneExample() {
        Injector injector = Guice.createInjector(new AllInOneExample.DoublePropertyModule());
        DoublePropertyConsumer consumer = injector.getInstance(DoublePropertyConsumer.class);
        consumer.test();
    }

    public static void main(String[] args) {
        new AllInOneExample();
    }

    static class DoublePropertyConsumer {

        DoubleProperty d0;
        DoubleProperty d1;
        DoubleProperty d0_2;

        @Inject
        public DoublePropertyConsumer(//
                @Named("d0") DoubleProperty d0, //
                @Named("d1") DoubleProperty d1, //
                @Named("d0_2") DoubleProperty d0_2//
        ) {
            this.d0 = d0;
            this.d1 = d1;
            this.d0_2 = d0_2;
        }

        public void test() {
            System.out.println("test()");
            d0.set(1);
            d1.set(2);
            d0_2.set(4);

            System.out.println("expected: false & actual -> " + (d0.get() == d1.get()));
            System.out.println("expected: true  & actual -> " + (d0.get() == d0_2.get()));
            System.out.println("expected: true  & actual -> " + (d0 == d0_2));
        }
    }

    static class DoublePropertyFactory {

        private Map<String, DoubleProperty> dMap = new HashMap<String, DoubleProperty>();

        public DoubleProperty buildProperty(String name) {
            DoubleProperty d = dMap.get(name);
            if (d == null) {
                d = new SimpleDoubleProperty();
                dMap.put(name, d);
            }
            return d;
        }
    }

    static class DoublePropertyModule extends AbstractModule {

        @Override
        protected void configure() {
            DoublePropertyFactory doublePropertyFactory = new DoublePropertyFactory();

            requestInjection(doublePropertyFactory);

            // bind(DoubleProperty.class).annotatedWith(Named.class).toInstance(doublePropertyFactory .buildProperty(???)));
            bind(DoubleProperty.class).annotatedWith(Names.named("d0"))
                    .toInstance(doublePropertyFactory.buildProperty("d0"));
            bind(DoubleProperty.class).annotatedWith(Names.named("d1"))
                    .toInstance(doublePropertyFactory.buildProperty("d1"));
            bind(DoubleProperty.class).annotatedWith(Names.named("d0_2"))
                    .toInstance(doublePropertyFactory.buildProperty("d0"));
        }
    }
}