Lambda Expressionとは？？
- using Anonymous class
dispbutton.addActionListener(new ActionListener() { // Using Anonymous Class
public void actionPerformed(ActionEvent e) {
contents.setText("Hello World! - By Anonymous Class"); }
}); // Using Anonymous Class
add(dispbutton); //AddthebuttonobjecttothisFrame
- using Lambda expression
dispbutton.addActionListener(e -> contents.setText("Hellow World! - By Lambda Expression"));
add(dispbutton); //AddthebuttonobjecttothisFrame
文法
Event Listener
Anonymous class
...
button1 = new JButton("foobar");
button1.addActionListener(this);
...
public void actionPerformed(ActionEvent e) {
if (e.getSource() == button1) {
//do something
}
...
}
...
Lambda expression
...
button1 = new JButton("foobar");
button1.addActionListener(e -> button1Click());
...
public void button1Click() {
//do something
}
Thread run method
Anonymous class
Runnable runner = new Runnable() {
@Override
public void run() {
System.out.println("example");
}
};
runner.run();
Lambda expression
Runnable runner = () -> { System.out.println("example"); };
runner.run();
Collection method
Anonymous class
List<Integer> list = Arrays.asList(1, 3, 2);
Collections.sort(list, new Comparator<Integer>() {
@Override
public int compare(Integer o1, Integer o2) {
return Integer.compare(o1, o2); }
}
);
Lambda expression
List<Integer> list = Arrays.asList(1, 3, 2);
Collections.sort(list, (o1, o2) -> Integer.compare(o1, o2));
