From d5950341dd8439c54e6e446cd3335aa8fcfc1c7e Mon Sep 17 00:00:00 2001
From: baihuijuan <3078948726@qq.com>
Date: Thu, 7 May 2026 15:15:16 +0800
Subject: [PATCH] =?UTF-8?q?=E5=AE=8C=E6=88=90Pair<K,V>=E5=8F=8A=E5=85=B6sw?=
 =?UTF-8?q?ap=E6=96=B9=E6=B3=95?=
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---
 w8/AI         |  5 +++++
 w8/Cache.java | 26 ++++++++++++++++++++++++++
 w8/Pair.java  | 23 +++++++++++++++++++++++
 3 files changed, 54 insertions(+)
 create mode 100644 w8/AI
 create mode 100644 w8/Cache.java
 create mode 100644 w8/Pair.java

diff --git a/w8/AI b/w8/AI
new file mode 100644
index 0000000..8efb943
--- /dev/null
+++ b/w8/AI
@@ -0,0 +1,5 @@
+3.AI协同学习：泛型擦除后如何通过反射获取泛型信息？
+答案：擦除后，运行时拿不到类型参数k、V的实际值。但可以通过反射获取字段、方法参数/返回值上声明的泛型信息（如List<String>中的String)
+4.思考题：为什么Java泛型不支持基本类型？
+根本原因:Java泛型通过类型擦除实现，编译后所有泛型参数都被替换为Object（或上界类型）。而基本类型(int、double等）不继承自 object，无法直接放入0bject容器中。
+解法：使用对应的包装类（Integer Double）.依赖自动装箱/拆箱
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diff --git a/w8/Cache.java b/w8/Cache.java
new file mode 100644
index 0000000..01b861c
--- /dev/null
+++ b/w8/Cache.java
@@ -0,0 +1,26 @@
+import java.util.HashMap;
+import java.util.Map;
+
+public class Cache<K, V> {
+    private final Map<K, V> cache = new HashMap<>();
+
+    public void put(K key, V value) {
+        cache.put(key, value);
+    }
+
+    public V get(K key) {
+        return cache.get(key);
+    }
+
+    public boolean containsKey(K key) {
+        return cache.containsKey(key);
+    }
+
+    public int size() {
+        return cache.size();
+    }
+
+    public void clear() {
+        cache.clear();
+    }
+}
\ No newline at end of file
diff --git a/w8/Pair.java b/w8/Pair.java
new file mode 100644
index 0000000..d572c9c
--- /dev/null
+++ b/w8/Pair.java
@@ -0,0 +1,23 @@
+public class Pair<K, V> {
+    private K key;
+    private V value;
+
+    public Pair(K key, V value) {
+        this.key = key;
+        this.value = value;
+    }
+
+    public K getKey() { return key; }
+    public V getValue() { return value; }
+
+    // 交换后 key/value 类型可能变化，所以返回新的 Pair<V, K>
+    public Pair<V, K> swap() {
+        return new Pair<>(this.value, this.key);
+    }
+
+    public static void main(String[] args) {
+        Pair<String, Integer> p = new Pair<>("Age", 25);
+        Pair<Integer, String> swapped = p.swap();
+        System.out.println(swapped.getKey() + "=" + swapped.getValue()); // 25=Age
+    }
+}
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