From a7a5cdaccb36f1d7729fd8fdbfd899de7dd5beea Mon Sep 17 00:00:00 2001
From: WangHe <2260378191@qq.com>
Date: Thu, 30 Apr 2026 14:36:49 +0800
Subject: [PATCH] =?UTF-8?q?=E4=B8=8A=E4=BC=A0=E6=96=87=E4=BB=B6=E8=87=B3?=
 =?UTF-8?q?=20'w8'?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 w8/AI_help.txt | 32 ++++++++++++++++++++++++++++++++
 w8/Cache.java  | 26 ++++++++++++++++++++++++++
 w8/Pair.java   | 20 ++++++++++++++++++++
 3 files changed, 78 insertions(+)
 create mode 100644 w8/AI_help.txt
 create mode 100644 w8/Cache.java
 create mode 100644 w8/Pair.java

diff --git a/w8/AI_help.txt b/w8/AI_help.txt
new file mode 100644
index 0000000..a95cc99
--- /dev/null
+++ b/w8/AI_help.txt
@@ -0,0 +1,32 @@
+Java泛型是“伪泛型”（类型擦除）
+
+运行时大部分泛型信息被擦掉，但：
+
+类的泛型信息（声明时）还能拿到
+
+泛型基于“类型擦除”
+
+泛型在编译后变成：Object
+但：
+
+int 不是对象
+Object 不能接收 int
+
+所以不能支持 int
+
+JVM设计限制
+
+Java泛型是在编译器层实现的（不是JVM层）
+→ JVM根本不知道泛型
+
+解决方案：包装类
+
+用：
+
+Integer 替代 int
+Double 替代 double
+
+自动装箱：
+
+Cache<String, Integer> cache = new Cache<>();
+cache.put("a", 1); // 自动装箱
\ No newline at end of file
diff --git a/w8/Cache.java b/w8/Cache.java
new file mode 100644
index 0000000..5d247cb
--- /dev/null
+++ b/w8/Cache.java
@@ -0,0 +1,26 @@
+import java.util.HashMap;
+import java.util.Map;
+
+public class Cache<K, V> {
+    private 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 contains(K key) {
+        return cache.containsKey(key);
+    }
+
+    public void remove(K key) {
+        cache.remove(key);
+    }
+
+    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..7dfbcbf
--- /dev/null
+++ b/w8/Pair.java
@@ -0,0 +1,20 @@
+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; }
+
+    public void setKey(K key) { this.key = key; }
+    public void setValue(V value) { this.value = value; }
+
+    // swap方法
+    public Pair<V, K> swap() {
+        return new Pair<>(value, key);
+    }
+}
\ No newline at end of file