将类型参数传递给接口的方法

Question

有以下类：

public abstract class AbstractWriter<T extends BE> {

    protected final T be;
    // Constructor, some methods

    public static interface Setter {
       void setNewValue();
    }

    protected <S> void setValue(final Class<S> clazz, final S oldValue,
        final S newValue, final Setter setter) {
        // Do something
        setter.setNewValue();
        // Do something
    }       
}

然后是 PersonWriter，它扩展了 AbstractWriter 并且目前看起来像这样：

public class PersonWriter extends AbstractWriter<BEPerson> {

    public PersonWriter(BEPerson be) {
        super(be);
    }

    public void setName(String oldValue, final String newValue) {
        setValue(String.class, oldValue, newValue, new Setter() {
            @Override
            public void setNewValue() {
                be.setName(newValue);
            }
        });
    };
}

但我希望 setName 看起来像这样：

    public void setName(String oldValue, String newValue) {
        setValue(String.class, oldValue, newValue, new Setter() {
            @Override
            public void setNewValue(String newValue) {
                be.setName(newValue);
            }
        });
    };

如何做我必须修改 AbstractWriter 才能使其工作（如果可能的话）？

Answer 1

您似乎要走很长的路才能在字段上调用 ​​setter 函数;-)。当 newValue 是 String 时，您希望知道 setValue 调用中的 new Setter() 是怎样的> 什么时候是别的东西？

有了setter的类型参数，我想应该不难：

public abstract class AbstractWriter<T extends BE> {
    //...
    public static interface Setter<S> {
        void setNewValue(S newValue);
    }

    protected <S> void setValue(final Class<S> clazz, final S oldValue,
        final S newValue, final Setter<S> setter) {
        // Do something
        setter.setNewValue(newValue);
        // Do something
    }    
}   

Answer 2

这是您要找的吗？

class BE {
}

class BEPerson extends BE {
    void setName(String s) {}
    void setAge(Integer i) {}
}

public abstract class AbstractWriter<T extends BE> {

    protected final T be;
    // Constructor, some methods
    AbstractWriter(T be) { this.be = be; }

    public static interface Setter<S> {
       void setNewValue(S v);
    }

    protected <S> void setValue(final Class<S> clazz, final S oldValue,
        final S newValue, final Setter setter) {
        // Do something
        setter.setNewValue(newValue);
        // Do something
    }       
}

class PersonWriter extends AbstractWriter<BEPerson> {

    public PersonWriter(BEPerson be) {
        super(be);
    }

    public void setName(String oldValue, final String newValue) {
        setValue(String.class, oldValue, newValue, new Setter<String>() {
            @Override
            public void setNewValue(String newValue) {
                be.setName(newValue);
            }
        });
    };

    public void setAge(Integer oldValue, final Integer newValue) {
        setValue(Integer.class, oldValue, newValue, new Setter<Integer>() {
            @Override
            public void setNewValue(Integer newValue) {
                be.setAge(newValue);
            }
        });
    };
}