Question

我读过，在基于XML的Spring配置bean中可以继承工厂方法我试图实施它：

控制器接口：

public interface Controller {
    String method();
}

ControllerFactory类：

public class ControllerFactory {
    public Controller getController(String controllerName){
        switch(controllerName){
            case "OtherController":
                return new OtherController();
            case "SampleController":
                return new SampleController();
            default:
                throw new IllegalArgumentException("Wrong controller name.");
        }
    }
}

SampleController实现：

public class SampleController implements Controller {
    @Override
    public String method() {
        return "SampleController";
    }
}

OtherController实现：

public class OtherController implements Controller {
    @Override
    public String method() {
        return "OtherController";
    }
}

但是以下XML配置：

<!--factory method inheritance -->
<bean id="controllerFactory" class="factory.ControllerFactory"/>
<bean id="parentController" abstract="true" factory-bean="controllerFactory" factory-method="getController"/>
<bean id="otherController" parent="parentController">
    <constructor-arg index="0" value="OtherController"/>
</bean>

给出编译时错误：

No matching constructor found in class 'Controller'

如何更改它以正确实现工厂方法bean继承？

将工厂方法配置复制到子bean按预期工作：

<bean id="otherController" parent="parentController" factory-bean="controllerFactory" factory-method="getController">
    <constructor-arg index="0" value="OtherController"/>
</bean>

Answer 1

更改标识为parentController的bean，如下所示：

<bean id="parentController" class="factory.ControllerFactory" factory-bean="controllerFactory" factory-method="getController"> <constructor-arg index="0" value="OtherController"/> </bean>。

试试这个可行。

Spring XML配置中的工厂方法bean继承

1 个答案: