# lambda表达式 1、用lambda表达式实现Runnable：`() -> {}`代码块替代了整个匿名类 ```java // Java 8之前： new Thread(new Runnable() { @Override public void run() { System.out.println("Before Java8, too much code for too little to do"); } }).start(); //Java 8方式： new Thread(() -> System.out.println("In Java8, Lambda expression rocks !!")).start(); ``` 你可以使用lambda写出如下代码： ```java (params) -> expression (params) -> statement (params) -> { statements } ``` 2、使用Java 8 lambda表达式进行事件处理 ```java // Java 8之前： JButton show = new JButton("Show"); show.addActionListener(new ActionListener() { @Override public void actionPerformed(ActionEvent e) { System.out.println("Event handling without lambda expression is boring"); } }); // Java 8方式： show.addActionListener((e) -> { System.out.println("Light, Camera, Action !! Lambda expressions Rocks"); }); ``` 3、使用lambda表达式对列表进行迭代 ```java // Java 8之前： List features = Arrays.asList("Lambdas", "Default Method", "Stream API", "Date and Time API"); for (String feature : features) { System.out.println(feature); } // Java 8之后： List features = Arrays.asList("Lambdas", "Default Method", "Stream API", "Date and Time API"); features.forEach(n -> System.out.println(n)); //或者使用这种方式，即方法引用由::双冒号操作符标示， features.forEach(System.out::println); ``` 来源：[Java8 lambda表达式10个示例](http://www.importnew.com/16436.html)