// 传统匿名内部类
new Thread(new Runnable() {
    @Override
    public void run() {
        System.out.println("Hello from traditional anonymous class");
    }
}).start();

// Lambda 表达式
new Thread(() -> System.out.println("Hello from Lambda")).start();

@FunctionalInterface
interface Greeting {
    void sayHello(String name);
}

public class Main {
    public static void main(String[] args) {
        Greeting greeting = name -> System.out.println("Hello, " + name);
        greeting.sayHello("Alice"); // 输出 Hello, Alice
    }
}

List<String> names = Arrays.asList("Alice", "Bob", "Charlie");
// Lambda 表达式
names.forEach(name -> System.out.println(name));
// 方法引用
names.forEach(System.out::println);

List<String> names = Arrays.asList("Alice", "Bob", "Charlie", "David");
List<String> result = names.stream()
    .filter(name -> name.startsWith("A"))  // 筛选以 A 开头
    .map(String::toUpperCase)               // 转大写
    .sorted()                               // 排序
    .collect(Collectors.toList());          // 收集结果
System.out.println(result); // [ALICE]

// 传统方式：多重循环与中间集合
int maxLen = 0;
for (String s : strings) {
    if (s.startsWith("A")) {
        int len = s.length();
        maxLen = Math.max(maxLen, len);
    }
}
System.out.println(maxLen);

// Lambda + Stream：一次流水线，代码更简洁
int maxLen2 = strings.stream()
    .filter(s -> s.startsWith("A"))
    .mapToInt(String::length)
    .max()
    .orElse(0);
System.out.println(maxLen2);