动态找到正确的方法以避免重复相同的代码

Question

以下代码将侦听器添加到多个 SWT 文本元素。唯一的区别是 Listeners 方法中的代码。有没有办法通过找到正确的动态使用方法来减少这段代码的重复性？

在此示例中使用了 FocusListener，但它不相关。

private void addFocusLostListeners() {
    nameText.addFocusListener(new FocusListener() {
        @Override
        public void focusGained(FocusEvent e) {}
        @Override
        public void focusLost(FocusEvent e) {
            myDataObject.setName(nameText.getText());
        }
    });
    ageText.addFocusListener(new FocusListener() {
        @Override
        public void focusGained(FocusEvent e) {}
        @Override
        public void focusLost(FocusEvent e) {
            myDataObject.setAge(ageText.getText());
        }
    });
    emailText.addFocusListener(new FocusListener() {
        @Override
        public void focusGained(FocusEvent e) {}
        @Override
        public void focusLost(FocusEvent e) {
            myDataObject.setEmail(emailText.getText());
        }
    });
    ...
}

Answer 1

你可以制作一个辅助方法（你需要用 nameText、ageText 等的实际 class 替换 TextField：

private static void addFocusListener(TextField field, Consumer<? super String> setter) {
    field.addFocusListener(new FocusListener() {
        @Override
        public void focusGained(FocusEvent e) {}
        @Override
        public void focusLost(FocusEvent e) {
            setter.accept(field.getText());
        }
    });
}

然后您可以调用：

private void addFocusLostListeners() {
    addFocusListener(nameText, myDataObject::setName);
    addFocusListener(ageText, myDataObject::setAge);
    addFocusListener(emailText, myDataObject::setEmail);
}

动态找到正确的方法以避免重复相同的代码

Dynamically find the correct method in order to not repeat the same code

java

refactoring

design-patterns

dry

java-8