具有不同签名但相同主体的功能
Functions with different signatures, but the same body
考虑 class
import javax.swing.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
public class ShortcutButton extends JButton {
public ShortcutButton(String text, KeyStroke[] keyStrokes, ActionListener actionListener) {
super(text);
addActionListener(actionListener);
addShortcut(keyStrokes);
}
public ShortcutButton(String text, KeyStroke keyStrokes, ActionListener actionListener) {
super(text);
addActionListener(actionListener);
addShortcut(keyStrokes);
}
public ShortcutButton(String text, String[] keyStrokes, ActionListener actionListener) {
super(text);
addActionListener(actionListener);
addShortcut(keyStrokes);
}
public ShortcutButton(String text, String keyStrokes, ActionListener actionListener) {
super(text);
addActionListener(actionListener);
addShortcut(keyStrokes);
}
public void addShortcuts(KeyStroke[] keyStrokes) {
for (KeyStroke keyStroke : keyStrokes) {
addShortcut(keyStroke);
}
}
public void addShortcuts(String[] keyStrokes) {
for (String keyStroke : keyStrokes) {
addShortcut(keyStroke);
}
}
public void addShortcut(String keyStroke) {
addShortcut(KeyStroke.getKeyStroke(keyStroke));
}
public void addShortcut(KeyStroke keyStroke) {
//some code here
}
}
如您所见,ShortcutButton()
构造函数和 addShortcuts()
函数具有不同的签名,但主体相同。有没有一种漂亮的方法可以缩短这段代码,以免在四个不同的函数中复制粘贴相同的代码?
您可以创建泛型方法,如下所示:
public<T> void addShortcuts(T[] keyStrokes) {
for (T keyStroke : keyStrokes) {
addShortcut(keyStroke);
}
}
如果您重新排序参数并使用可变参数,您可以将它们缩减为两个构造函数:
public ShortcutButton(String text, ActionListener actionListener, KeyStroke... keyStrokes) {
super(text);
addActionListener(actionListener);
addShortcuts(keyStrokes);
}
public ShortcutButton(String text, ActionListener actionListener, String... keyStrokes) {
super(text);
addActionListener(actionListener);
addShortcuts(keyStrokes);
}
并且如果您有将 String[]
转换为 KeyStroke[]
的方法,您可以进一步缩短代码:
public ShortcutButton(String text, ActionListener actionListener, KeyStroke... keyStrokes) {
super(text);
addActionListener(actionListener);
addShortcuts(keyStrokes);
}
public ShortcutButton(String text, ActionListener actionListener, String... keyStrokes) {
this(text,actionListener,getShortCuts(keyStrokes));
}
除了其他答案之外,您还可以使用一个技巧,通过添加私有构造函数至少将 addActionListener(actionListener);
从您的专用构造函数中拉出。这不是来自其他答案的 varargs 技巧的替代方法。您可以应用这两种技巧来获得更小的代码。
public class ShortcutButton extends JButton {
/** Construct a ShortcutButton without keystrokes. Any constructor calling this should add keystrokes themselves. */
private ShortcutButton(String text, ActionListener actionListener) {
super(text);
addActionListener(actionListener);
}
public ShortcutButton(String text, KeyStroke[] keyStrokes, ActionListener actionListener) {
this(text, actionListener);
addShortcut(keyStrokes);
}
public ShortcutButton(String text, KeyStroke keyStrokes, ActionListener actionListener) {
this(text, actionListener);
addShortcut(keyStrokes);
}
public ShortcutButton(String text, String[] keyStrokes, ActionListener actionListener) {
this(text, actionListener);
addShortcut(keyStrokes);
}
public ShortcutButton(String text, String keyStrokes, ActionListener actionListener) {
this(text, actionListener);
addShortcut(keyStrokes);
}
...
}
考虑 class
import javax.swing.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
public class ShortcutButton extends JButton {
public ShortcutButton(String text, KeyStroke[] keyStrokes, ActionListener actionListener) {
super(text);
addActionListener(actionListener);
addShortcut(keyStrokes);
}
public ShortcutButton(String text, KeyStroke keyStrokes, ActionListener actionListener) {
super(text);
addActionListener(actionListener);
addShortcut(keyStrokes);
}
public ShortcutButton(String text, String[] keyStrokes, ActionListener actionListener) {
super(text);
addActionListener(actionListener);
addShortcut(keyStrokes);
}
public ShortcutButton(String text, String keyStrokes, ActionListener actionListener) {
super(text);
addActionListener(actionListener);
addShortcut(keyStrokes);
}
public void addShortcuts(KeyStroke[] keyStrokes) {
for (KeyStroke keyStroke : keyStrokes) {
addShortcut(keyStroke);
}
}
public void addShortcuts(String[] keyStrokes) {
for (String keyStroke : keyStrokes) {
addShortcut(keyStroke);
}
}
public void addShortcut(String keyStroke) {
addShortcut(KeyStroke.getKeyStroke(keyStroke));
}
public void addShortcut(KeyStroke keyStroke) {
//some code here
}
}
如您所见,ShortcutButton()
构造函数和 addShortcuts()
函数具有不同的签名,但主体相同。有没有一种漂亮的方法可以缩短这段代码,以免在四个不同的函数中复制粘贴相同的代码?
您可以创建泛型方法,如下所示:
public<T> void addShortcuts(T[] keyStrokes) {
for (T keyStroke : keyStrokes) {
addShortcut(keyStroke);
}
}
如果您重新排序参数并使用可变参数,您可以将它们缩减为两个构造函数:
public ShortcutButton(String text, ActionListener actionListener, KeyStroke... keyStrokes) {
super(text);
addActionListener(actionListener);
addShortcuts(keyStrokes);
}
public ShortcutButton(String text, ActionListener actionListener, String... keyStrokes) {
super(text);
addActionListener(actionListener);
addShortcuts(keyStrokes);
}
并且如果您有将 String[]
转换为 KeyStroke[]
的方法,您可以进一步缩短代码:
public ShortcutButton(String text, ActionListener actionListener, KeyStroke... keyStrokes) {
super(text);
addActionListener(actionListener);
addShortcuts(keyStrokes);
}
public ShortcutButton(String text, ActionListener actionListener, String... keyStrokes) {
this(text,actionListener,getShortCuts(keyStrokes));
}
除了其他答案之外,您还可以使用一个技巧,通过添加私有构造函数至少将 addActionListener(actionListener);
从您的专用构造函数中拉出。这不是来自其他答案的 varargs 技巧的替代方法。您可以应用这两种技巧来获得更小的代码。
public class ShortcutButton extends JButton {
/** Construct a ShortcutButton without keystrokes. Any constructor calling this should add keystrokes themselves. */
private ShortcutButton(String text, ActionListener actionListener) {
super(text);
addActionListener(actionListener);
}
public ShortcutButton(String text, KeyStroke[] keyStrokes, ActionListener actionListener) {
this(text, actionListener);
addShortcut(keyStrokes);
}
public ShortcutButton(String text, KeyStroke keyStrokes, ActionListener actionListener) {
this(text, actionListener);
addShortcut(keyStrokes);
}
public ShortcutButton(String text, String[] keyStrokes, ActionListener actionListener) {
this(text, actionListener);
addShortcut(keyStrokes);
}
public ShortcutButton(String text, String keyStrokes, ActionListener actionListener) {
this(text, actionListener);
addShortcut(keyStrokes);
}
...
}