Java中使用接口实现回调函数的示例详解

// Callback.java
public interface Callback {
    void onComplete(String message);
}

// CallbackImpl.java
public class CallbackImpl implements Callback {
    @Override
    public void onComplete(String message) {
        System.out.println("Callback received: " + message);
    }
}

// Task.java
public class Task {
    private Callback callback;

    public Task(Callback callback) {
        this.callback = callback;
    }

    public void execute() {
        // 模拟一些任务
        System.out.println("Executing task...");

        // 任务完成后，触发回调
        if (callback != null) {
            callback.onComplete("Task completed successfully!");
        }
    }
}

// Main.java
public class Main {
    public static void main(String[] args) {
        // 创建回调实现
        Callback callback = new CallbackImpl();
        
        // 创建任务，并传递回调实现
        Task task = new Task(callback);

        // 执行任务
        task.execute();
    }
}

Executing task...
Callback received: Task completed successfully!

// Main.java
public class Main {
    public static void main(String[] args) {
        // 使用匿名内部类实现回调
        Task task = new Task(new Callback() {
            @Override
            public void onComplete(String message) {
                System.out.println("Callback received: " + message);
            }
        });

        // 执行任务
        task.execute();
    }
}

// Main.java
public class Main {
    public static void main(String[] args) {
        // 使用Lambda表达式实现回调
        Task task = new Task(message -> System.out.println("Callback received: " + message));

        // 执行任务
        task.execute();
    }
}