在模塊化開發中，時不時會遇到跨模塊調用功能，引入了ARouter可以做到跨模塊調用，那如果項目沒有引入ARouter呢，那這里可以自己做多模塊暴露接口調用功能。

這里示例做了從業務模塊中調用主app module中的一個用戶信息，從角色上分為app模塊，base-module模塊，module-one模塊和module-two模塊。

在公共模塊base-module模塊中

用戶實體類：

data class UserBean(val id: String, val name: String)

ServiceCreator類：

interface ServiceCreator<T> {
    fun create(): T
}

ServiceManager類：用于對暴露接口和實現類的綁定關系：

public final class ServiceManager {
    private static final ConcurrentHashMap<String, Object> sServices = new ConcurrentHashMap<>();
    private static final ConcurrentHashMap<String, ServiceCreator<?>> sServiceCreators = new ConcurrentHashMap<>();

    private ServiceManager() {
    }

    @SuppressWarnings("unchecked")
    public static <T> T getService(@NonNull Class<T> iCls) {
        return getService(iCls.getName());
    }

    @SuppressWarnings("unchecked")
    public static <T> T getService(@NonNull String name) {
        T service = (T) sServices.get(name);
        if (service == null) {
            synchronized (sServices) {
                service = (T) sServices.get(name);
                if (service == null) {
                    ServiceCreator<T> creator = (ServiceCreator) sServiceCreators.get(name);
                    if (creator != null) {
                        service = creator.create();
                        sServices.put(name, service);
                        sServiceCreators.remove(name);
                    }
                }
            }
        }
        return service;
    }

    public static <T> void registerService(@NonNull Class<T> iCls, @NonNull T obj) {
        registerService(iCls.getName(), obj);
    }

    public static <T> void registerService(@NonNull String name, @NonNull T obj) {
        sServices.put(name, obj);
    }

    public static <T> void registerService(@NonNull Class<T> iCls, @NonNull ServiceCreator<T> creator) {
        registerService(iCls.getName(), creator);
    }

    public static <T> void registerService(@NonNull String name, @NonNull ServiceCreator<T> creator) {
        sServiceCreators.put(name, creator);
    }

    public static <T> void unregisterService(@NonNull Class<T> iCls) {
        unregisterService(iCls.getName());
    }

    public static <T> void unregisterService(@NonNull String name) {
        sServices.remove(name);
        sServiceCreators.remove(name);
    }

    public static void clearAll(){
        sServices.clear();
        sServiceCreators.clear();
    }
}

base模塊中聲明需要暴露功能的接口：

public interface IModuleConnect {

    UserBean getUserBean();
}

在module-two模塊中：

實現該接口功能：

public class IModuleConnectImp implements IModuleConnect {
    @Override
    public UserBean getUserBean() {
        UserBean userBean = new UserBean("", "IModuleConnectImp");
        return userBean;
    }
}

在application中

注冊該暴露接口和實現類，將接口和實現類在map中進行一一綁定。

        //注冊service
        ServiceManager.registerService(IModuleConnect::class.java, IModuleConnectImp())

在module-one業務模塊中：

從ServiceManager的hashmap中獲取實現接口，調用接口類實現的方法：

        IModuleConnect service = ServiceManager.getService(IModuleConnect.class);
        UserBean userBean = service.getUserBean();

這里是Github代碼參考