{"id":201103,"date":"2025-05-10T08:25:00","date_gmt":"2025-05-10T00:25:00","guid":{"rendered":"https:\/\/server.hk\/cnblog\/201103\/"},"modified":"2025-05-10T08:25:00","modified_gmt":"2025-05-10T00:25:00","slug":"%e6%89%8b%e5%8a%a8%e5%ae%9e%e7%8e%b0redis%e7%9a%84lru%e7%bc%93%e5%ad%98%e6%9c%ba%e5%88%b6%e7%a4%ba%e4%be%8b%e8%af%a6%e8%a7%a3","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/201103\/","title":{"rendered":"\u624b\u52a8\u5b9e\u73b0Redis\u7684LRU\u7f13\u5b58\u673a\u5236\u793a\u4f8b\u8be6\u89e3"},"content":{"rendered":"<p><b><\/b> <\/p>\n<h1>\u624b\u52a8\u5b9e\u73b0Redis\u7684LRU\u7f13\u5b58\u673a\u5236\u793a\u4f8b\u8be6\u89e3<\/h1>\n<p><span style=\"cursor: pointer\"><i><\/i>\u6536\u85cf<\/span> <\/p>\n<p>\u4eb2\u7231\u7684\u7f16\u7a0b\u5b66\u4e60\u7231\u597d\u8005\uff0c\u5982\u679c\u4f60\u70b9\u5f00\u4e86\u8fd9\u7bc7\u6587\u7ae0\uff0c\u8bf4\u660e\u4f60\u5bf9\u300a\u624b\u52a8\u5b9e\u73b0Redis\u7684LRU\u7f13\u5b58\u673a\u5236\u793a\u4f8b\u8be6\u89e3\u300b\u5f88\u611f\u5174\u8da3\u3002\u672c\u7bc7\u6587\u7ae0\u5c31\u6765\u7ed9\u5927\u5bb6\u8be6\u7ec6\u89e3\u6790\u4e00\u4e0b\uff0c\u4e3b\u8981\u4ecb\u7ecd\u4e00\u4e0b\u7f13\u5b58\u3001RedisLRU\uff0c\u5e0c\u671b\u6240\u6709\u8ba4\u771f\u8bfb\u5b8c\u7684\u7ae5\u978b\u4eec\uff0c\u90fd\u6709\u5b9e\u8d28\u6027\u7684\u63d0\u9ad8\u3002<\/p>\n<h3>\u7b2c\u4e00\u79cd\u5b9e\u73b0(\u4f7f\u7528LinkedHashMap)<\/h3>\n<pre>\npublic class LRUCache {\n\n  int capacity;\n  Map\n   \n     map;\n\n  public LRUCache(int capacity){\n    this.capacity = capacity;\n    map = new LinkedHashMap();\n  }\n\n  public int get(int key){\n    \/\/\u5982\u679c\u6ca1\u6709\u627e\u5230\n    if (!map.containsKey(key)){\n      return -1;\n    }\n    \/\/\u627e\u5230\u4e86\u5c31\u5237\u65b0\u6570\u636e\n    Integer value = map.remove(key);\n    map.put(key,value);\n    return value;\n  }\n\n  public void put(int key,int value){\n    if (map.containsKey(key)){\n      map.remove(key);\n      map.put(key,value);\n      return;\n    }\n    map.put(key,value);\n    \/\/\u8d85\u51facapacity\uff0c\u5220\u9664\u6700\u4e45\u6ca1\u7528\u7684\u5373\u7b2c\u4e00\u4e2a,\u6216\u8005\u53ef\u4ee5\u590d\u5199removeEldestEntry\u65b9\u6cd5\n    if (map.size() &gt; capacity){\n      map.remove(map.entrySet().iterator().next().getKey());\n    }\n  }\n\n  public static void main(String[] args) {\n    LRUCache lruCache = new LRUCache(10);\n    for (int i = 0; i \n\n\n    <p style=\"text-align: center\"><img decoding=\"async\" src=\"https:\/\/www.17golang.com\/uploads\/20221229\/167231162163ad7345d0eb7.png\" class=\"aligncenter\"><\/p>\n\n    <h3>\u7b2c\u4e8c\u79cd\u5b9e\u73b0(\u53cc\u94fe\u8868+hashmap)<\/h3>\n\n\n    <pre>\npublic class LRUCache {\n\n  private int capacity;\n  private Map\n     \n      map;\n  private ListNode head;\n  private ListNode tail;\n\n  public LRUCache2(int capacity){\n    this.capacity = capacity;\n    map = new HashMap();\n    head = new ListNode(-1,-1);\n    tail = new ListNode(-1,-1);\n    head.next = tail;\n    tail.pre = head;\n  }\n\n  public int get(int key){\n    if (!map.containsKey(key)){\n      return -1;\n    }\n    ListNode node = map.get(key);\n    node.pre.next = node.next;\n    node.next.pre = node.pre;\n    return node.val;\n  }\n\n  public void put(int key,int value){\n    if (get(key)!=-1){\n      map.get(key).val = value;\n      return;\n    }\n    ListNode node = new ListNode(key,value);\n    map.put(key,node);\n    moveToTail(node);\n\n    if (map.size() &gt; capacity){\n      map.remove(head.next.key);\n      head.next = head.next.next;\n      head.next.pre = head;\n    }\n  }\n\n  \/\/\u628a\u8282\u70b9\u79fb\u52a8\u5230\u5c3e\u5df4\n  private void moveToTail(ListNode node) {\n    node.pre = tail.pre;\n    tail.pre = node;\n    node.pre.next = node;\n    node.next = tail;\n  }\n\n  \/\/\u5b9a\u4e49\u53cc\u5411\u94fe\u8868\u8282\u70b9\n  private class ListNode{\n    int key;\n    int val;\n    ListNode pre;\n    ListNode next;\n\n    \/\/\u521d\u59cb\u5316\u53cc\u5411\u94fe\u8868\n    public ListNode(int key,int val){\n      this.key = key;\n      this.val = val;\n      pre = null;\n      next = null;\n    }\n  }\n}\n     <\/pre>\n<p>\u50cf\u7b2c\u4e00\u79cd\u65b9\u5f0f\uff0c\u5982\u679c\u590d\u5199removeEldestEntry\u4f1a\u66f4\u7b80\u5355\uff0c\u8fd9\u91cc\u7b80\u5355\u7684\u5c55\u793a\u4e00\u4e0b<\/p>\n<pre>\npublic class LRUCache extends LinkedHashMap\n     \n       {\n  private int capacity;\n  \n  @Override\n  protected boolean removeEldestEntry(Map.Entry\n      \n        eldest) { return size() &gt; capacity; } }\n      \n     <\/pre>\n","protected":false},"excerpt":{"rendered":"<p>\u624b\u52a8\u5b9e\u73b0Redis\u7684LRU\u7f13\u5b58\u673a&#46;&#46;&#46;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[101],"tags":[],"class_list":["post-201103","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/201103","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/comments?post=201103"}],"version-history":[{"count":0,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/201103\/revisions"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=201103"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=201103"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=201103"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}