Google guice - 多重绑定+泛型+辅助对象 [英] Google guice - multibinding + generics + assistedinject

问题描述

我有以下类：

  public interface Factory< T extends MyParentClass> {
 public T create（String parameter）; 
} 
 
 public class FactoryImpl1实现Factory< MyChildClass1> {
 public MyChildClass1 create（String parameter）{
 ... 
} 
} 
 
 public class FactoryImpl2实现Factory< MyChildClass2> {
 MyChildClass2 create（String parameter）{
 ... 
} 
} 
 
 public class MyModule extends AbstractModule {
 @Override 
 protected void configure（）{
 MapBinder< String，Factory< MyParentClass>> factoryMap = MapBinder.newMapBinder（binder（），new TypeLiteral< String>（）{}，new TypeLiteral< Factory< MyParentClass>>（）{}）; 
 factoryMap.addBinding（myKey1）。（FactoryImpl1.class）; 
 factoryMap.addBinding（myKey2）。（FactoryImpl2.class）; 
 
 
  

我的模块中的语法不正确， '知道如何配置这个。

事实上，我想为我的工厂界面中的每个可能的工厂都有一个工厂。

解决方案

工厂< MyParentClass> 不是超类型的 Factory< MyChildClass1> ，您需要指定通配符泛型（在这种情况下绑定或非绑定并不重要，因为您已将它绑定到Factory

试一下

  MapBinder< String，Factory< ？>> （），new TypeLiteral< String> 
  

检查这里为泛型之间的超类型关系。

I have the following classes :

public interface Factory<T extends MyParentClass> {
    public T create(String parameter);
}

public class FactoryImpl1 implements Factory<MyChildClass1> {
    public MyChildClass1 create(String parameter){
    ...
    }
}

public class FactoryImpl2 implements Factory<MyChildClass2> {
    public MyChildClass2 create(String parameter){
    ...
    }
}

public class MyModule extends AbstractModule {
    @Override
    protected void configure() {
        MapBinder<String, Factory<MyParentClass>> factoryMap = MapBinder.newMapBinder(binder(), new TypeLiteral<String>() {}, new TypeLiteral<Factory<MyParentClass>>(){});
        factoryMap.addBinding("myKey1").to(FactoryImpl1.class);
        factoryMap.addBinding("myKey2").to(FactoryImpl2.class);
    }
}

The syntax in my module is not correct and I don'know how to configure this.

In fact I would like to have a factory for each possible in my factory interface

Thanks in advance for your help.

解决方案

Factory<MyParentClass> is not supertype of Factory<MyChildClass1>, you need to specify a wildcard generic (bound or unbound in this case doesn't matter as you have bound it in the Factory definition).

Try with

MapBinder<String, Factory<?>> factoryMap = MapBinder.newMapBinder(binder(), new TypeLiteral<String>(){}, new TypeLiteral<Factory<?>>(){});

Check here for supertype relationships between generics.

这篇关于Google guice - 多重绑定+泛型+辅助对象的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！