面向中职计算机专业学生的教学思考

// 创建线程的两种基本方式
// 方式1：继承Thread类
class MyThread extends Thread {
    @Override
    public void run() {
        System.out.println("线程运行中...");
    }
}

// 方式2：实现Runnable接口
class MyRunnable implements Runnable {
    @Override
    public void run() {
        System.out.println("Runnable线程运行中...");
    }
}

// 线程同步示例
class Counter {
    private int count = 0;
    private final Object lock = new Object();
    
    public void increment() {
        synchronized(lock) {
            count++;
        }
    }
}

// List接口的常用实现类
List<String> arrayList = new ArrayList<>(); // 查询快，增删慢
List<String> linkedList = new LinkedList<>(); // 增删快，查询慢

// Map接口的常用实现类
Map<String, Integer> hashMap = new HashMap<>(); // 无序，允许null键值
Map<String, Integer> treeMap = new TreeMap<>(); // 按键排序

// 使用迭代器遍历集合
Iterator<String> it = arrayList.iterator();
while(it.hasNext()) {
    System.out.println(it.next());
}

// Java8的流式操作
list.stream()
    .filter(s -> s.length() > 3)
    .map(String::toUpperCase)
    .forEach(System.out::println);

// 传统IO文件读写
try (BufferedReader br = new BufferedReader(new FileReader("test.txt"))) {
    String line;
    while ((line = br.readLine()) != null) {
        System.out.println(line);
    }
} catch (IOException e) {
    e.printStackTrace();
}

// NIO文件读写
Path path = Paths.get("test.txt");
try {
    List<String> lines = Files.readAllLines(path, StandardCharsets.UTF_8);
    lines.forEach(System.out::println);
} catch (IOException e) {
    e.printStackTrace();
}

// 通道和缓冲区示例
try (FileChannel channel = FileChannel.open(path, StandardOpenOption.READ)) {
    ByteBuffer buffer = ByteBuffer.allocate(1024);
    while (channel.read(buffer) > 0) {
        buffer.flip();
        while (buffer.hasRemaining()) {
            System.out.print((char) buffer.get());
        }
        buffer.clear();
    }
}

// 获取Class对象的三种方式
Class<?> clazz1 = Class.forName("com.example.Student");
Class<?> clazz2 = Student.class;
Class<?> clazz3 = new Student().getClass();

// 通过反射创建对象并调用方法
try {
    // 获取构造方法
    Constructor<?> constructor = clazz1.getConstructor(String.class, int.class);
    
    // 创建实例
    Object obj = constructor.newInstance("张三", 18);
    
    // 调用方法
    Method method = clazz1.getMethod("study", String.class);
    method.invoke(obj, "Java编程");
    
    // 访问字段
    Field field = clazz1.getDeclaredField("age");
    field.setAccessible(true); // 设置可访问私有字段
    System.out.println(field.get(obj));
} catch (Exception e) {
    e.printStackTrace();
}

// 自定义注解
@Retention(RetentionPolicy.RUNTIME)
@Target(ElementType.METHOD)
public @interface MyAnnotation {
    String value() default "";
    int priority() default 0;
}

// 注解使用
class AnnotationDemo {
    @MyAnnotation(value = "测试方法", priority = 1)
    public void testMethod() {
        System.out.println("方法执行...");
    }
}

// 泛型类定义
class Box<T> {
    private T content;
    
    public void setContent(T content) {
        this.content = content;
    }
    
    public T getContent() {
        return content;
    }
}

// 泛型方法
public static <T> void printArray(T[] array) {
    for (T element : array) {
        System.out.print(element + " ");
    }
    System.out.println();
}