上传文件至 'w8'

w8/Cache.java

@@ -0,0 +1,116 @@
+import java.util.*;
+import java.util.concurrent.locks.ReentrantReadWriteLock;
+
+
+public class Cache<K, V> {
+    private final Map<K, V> store;
+    private final int maxCapacity;
+    private final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
+
+
+    public Cache(int maxCapacity) {
+        if (maxCapacity <= 0) {
+            throw new IllegalArgumentException("最大容量应为正数");
+        }
+        this.maxCapacity = maxCapacity;
+        this.store = new LinkedHashMap<K, V>(16, 0.75f, true) {
+            @Override
+            protected boolean removeEldestEntry(Map.Entry<K, V> eldest) {
+                return size() > maxCapacity;
+            }
+        };
+    }
+
+    public V put(K key, V value) {
+        lock.writeLock().lock();
+        try {
+            return store.put(key, value);
+        } finally {
+            lock.writeLock().unlock();
+        }
+    }
+
+    public V get(K key) {
+        lock.readLock().lock();
+        try {
+            return store.get(key);
+        } finally {
+            lock.readLock().unlock();
+        }
+    }
+
+    public V remove(K key) {
+        lock.writeLock().lock();
+        try {
+            return store.remove(key);
+        } finally {
+            lock.writeLock().unlock();
+        }
+    }
+
+    /**
+     * 清空所有缓存。
+     */
+    public void clear() {
+        lock.writeLock().lock();
+        try {
+            store.clear();
+        } finally {
+            lock.writeLock().unlock();
+        }
+    }
+
+    /**
+     * 当前缓存中的条目数。
+     */
+    public int size() {
+        lock.readLock().lock();
+        try {
+            return store.size();
+        } finally {
+            lock.readLock().unlock();
+        }
+    }
+
+    /**
+     * 判断是否包含某个键。
+     */
+    public boolean containsKey(K key) {
+        lock.readLock().lock();
+        try {
+            return store.containsKey(key);
+        } finally {
+            lock.readLock().unlock();
+        }
+    }
+
+    @Override
+    public String toString() {
+        lock.readLock().lock();
+        try {
+            return store.toString();
+        } finally {
+            lock.readLock().unlock();
+        }
+    }
+
+    // ---------- 测试示例 ----------
+    public static void main(String[] args){
+        Cache<String,Integer> hc1 = new Cache<String,Integer>(3);
+
+        hc1.put("a",10);
+        hc1.put("b",6);
+        hc1.put("c",3);
+
+        System.out.println("b的值为" + hc1.get("b"));
+        System.out.println("a的值为" + hc1.get("a"));
+        System.out.println("缓存1的条目数（键值对数）为" + hc1.size());
+
+        hc1.remove("b");
+        System.out.println("删去b后，缓存1的条目数（键值对数）为" + hc1.size());
+        System.out.println("键中是否含有b：" + hc1.containsKey("b"));
+
+        hc1.clear();
+        System.out.println("清空缓存1后，缓存1的条目数（键值对数）为" + hc1.size());
+    }
+}

w8/Pair.java

@@ -0,0 +1,65 @@
+public class Pair<K, V> {
+    private K key;
+    private V value;
+
+    public Pair() {
+        this(null, null);
+    }
+
+    public Pair(K key, V value) {
+        this.key = key;
+        this.value = value;
+    }
+
+    public K getKey() {
+        return key;
+    }
+
+    public void setKey(K key) {
+        this.key = key;
+    }
+
+    public V getValue() {
+        return value;
+    }
+
+    public void setValue(V value) {
+        this.value = value;
+    }
+
+    @Override
+    public String toString() {
+        return "(" + key + ", " + value + ")";
+    }
+
+    public static <K,V> Pair<V,K> swap(Pair<K,V> pair){
+        return new Pair<>(pair.getValue(),pair.getKey());
+    }
+
+
+    // ---------- 测试示例 ----------
+    public static void main(String[] args) {
+        // 创建不同类型的 Pair 实例
+        Pair<String, Integer> pair1 = new Pair<>("age", 25);
+        Pair<String, String> pair2 = new Pair<>("name", "Alice");
+        Pair<Integer, Double> pair3 = new Pair<>(100, 99.5);
+
+        // 输出初始内容
+        System.out.println("pair1: " + pair1);
+        System.out.println("pair2: " + pair2);
+        System.out.println("pair3: " + pair3);
+
+        // 测试 getter
+        System.out.println("pair1 key: " + pair1.getKey() + ", value: " + pair1.getValue());
+
+        // 测试 setter
+        pair1.setValue(30);
+        System.out.println("修改后 pair1: " + pair1);
+
+        // 泛型方法使用示例：交换两个 Pair 的值（演示泛型灵活性）
+        Pair<String, Integer> a = new Pair<>("x", 1);
+        System.out.println("交换前: a=" + a );
+        Pair<Integer,String> b = swap(a);
+        System.out.println("交换后: b=" + b );
+    }
+}