Redis实战SpringBoot版本之购物车服务

序

本文主要是对第二章的购物车服务的代码从jredis改为SpringBoot的redis template版本。

主要功能

• 存储登录的用户

• 存储最近登录的用户列表

• 存储用户最近浏览的项目

• 存储用户的购物车

• 缓存请求内容/数据行

数据结构选择

• 用map存储登陆用户

• 用zset存储最近登陆的用户

• 用zset存储最近被浏览的item

• 用zset存储用户最近浏览的item

• 用map存储用户的购物车

常量声明

 /**      * 登录用户      * 数据结构 -- map      * key -- loginMap      * value -- k:token v:user      */     public static final String KEY_LOGIN_USER = "loginMap";      /**      * 最近登录用户      * 数据结构 -- zset      * key -- recentSet      * value -- v:token score:timestamp      */     public static final String KEY_RECENT_USER = "recentSet";      /**      * 项目浏览计数      */     public static final String KEY_ITEM_VIEW_COUNT = "itemViewedZSet";      /**      * 存储用户最近浏览的项目      * 数据结构 -- zset      * key -- viewZset:token      * value -- v:item score:timestamp      */     public static final String KEY_USER_VIEW_PREFIX = "viewZset:";      /**      * 用户购物车      * 数据结构 -- map      * key -- cartMap:session      * value -- k:item v:count      */     public static final String KEY_USER_CART_PREFIX = "cartMap:";      /**      * 请求的缓存      * 数据结构 -- string      * key -- cache:hashcode      * value -- string      */     public static final String KEY_CACHE_PREFIX = "cache:";      /**      * 缓存库存信息      * key -- inventory:rowId      * value -- json      */     public static final String KEY_INVENTORY_PREFIX = "inventory:";      /**      * 调度ZSet      * key -- scheduleZSet      * value -- k:rowId v:timestamp      */     public static final String KEY_SCHEDULE = "scheduleZSet";      /**      * 到期ZSet      * key -- delayZSet      * value -- k:rowId v:timestamp      */     public static final String KEY_DELAY = "delayZSet";

主要功能

用户浏览item

/**      * 用户浏览项目      * @param token      * @param user      * @param item      */     public void viewItem(String token,String user,String item){         long timestamp = System.currentTimeMillis()/1000;         //模拟登录下         redisTemplate.opsForHash().put(KEY_LOGIN_USER, token, user);         //更新最近登录         redisTemplate.boundZSetOps(KEY_RECENT_USER).add(token,timestamp);          if(item == null){             return ;         }          String userViewKey = formUserViewKey(token);         //添加最近浏览记录         redisTemplate.boundZSetOps(userViewKey).add(item,timestamp);         //缩减下最近浏览记录,保持在25条         redisTemplate.boundZSetOps(userViewKey).removeRange(0,-26);         //对项目浏览得分-1,最后升序排         redisTemplate.boundZSetOps(KEY_ITEM_VIEW_COUNT).incrementScore(item,-1);     }

用户添加购物车

/**      * 添加到购物车      * @param session      * @param item      * @param count      */     public void addToCart(String session,String item,int count){         String cartKey = formUserCartKey(session);         if(count <= 0){             redisTemplate.opsForHash().delete(cartKey,item);         }else{             redisTemplate.opsForHash().put(cartKey, item, String.valueOf(count));         }     }

缓存请求

/**      * 缓存请求      * @param request      * @param supplier      * @return      */     public String cacheRequest(String request,Supplier<String> supplier){         if(!canCache(request)){             //不走缓存             return supplier.get();         }          String pageKey = formCacheKey(request);         ValueOperations<String,String> ops = redisTemplate.opsForValue();         String content = ops.get(pageKey);         if(content == null && supplier != null){             //缓存不存在             content = supplier.get();             redisTemplate.opsForValue().setIfAbsent(pageKey,content);         }         return content;     }      /**      * 判断需不需要缓存该请求      * 浏览量上w的才请求      * @param request      * @return      */     public boolean canCache(String request){         try {             URL url = new URL(request);             Map<String,String> params = new HashMap<String,String>();             if (url.getQuery() != null){                 for (String param : url.getQuery().split("&")){                     String[] pair = param.split("=", 2);                     params.put(pair[0], pair.length == 2 ? pair[1] : null);                 }             }              String itemId = params.get("item");             if (itemId == null || params.containsKey("_")) {                 return false;             }             Long rank = redisTemplate.boundZSetOps(KEY_ITEM_VIEW_COUNT).rank(itemId);             return rank != null && rank < 10000;         }catch(MalformedURLException mue){             return false;         }     }

缓存请求行

/**      * 缓存数据行      * 1,取出schedule到期的数据项      * 2,取出该数据项的过期时间      * 3,更新该数据项的过期时间      */     class CacheRowsTask extends Thread{          private volatile boolean stop = false;          public void quit(){             stop = true;         }          @Override         public void run() {             Gson gson = new Gson();             while (!stop){                 //取第一个出来                 Set<ZSetOperations.TypedTuple> range = redisTemplate.boundZSetOps(KEY_SCHEDULE).rangeWithScores(0,0);                 ZSetOperations.TypedTuple next = range.size() > 0 ? range.iterator().next() : null;                 long now = System.currentTimeMillis() / 1000;                 if (next == null || next.getScore() > now){                     try {                         sleep(50);                     }catch(InterruptedException ie){                         Thread.currentThread().interrupt();                     }                     continue;                 }                  String rowId = (String) next.getValue();                 double delay = redisTemplate.boundZSetOps(KEY_DELAY).score(rowId);                 if (delay <= 0) {                     redisTemplate.boundZSetOps(KEY_DELAY).remove(rowId);                     redisTemplate.boundZSetOps(KEY_SCHEDULE).remove(rowId);                     redisTemplate.delete(formInventoryKey(rowId));                     continue;                 }                  Inventory row = Inventory.get(rowId);                 redisTemplate.opsForZSet().add(KEY_SCHEDULE, rowId, now + delay);                 redisTemplate.opsForValue().set(formInventoryKey(rowId), gson.toJson(row));             }         }     }      /**      * 被缓存的项      */     static class Inventory {         private String id;         private String data;         private long time;          private Inventory (String id) {             this.id = id;             this.data = "data to cache...";             this.time = System.currentTimeMillis() / 1000;         }          public static Inventory get(String id) {             return new Inventory(id);         }     }

缓存调度

/**      * 初始化缓存调度      * @param rowId      * @param delay      */     public void scheduleRowCache(String rowId, int delay) {         redisTemplate.opsForZSet().add(KEY_DELAY,rowId,delay);         redisTemplate.opsForZSet().add(KEY_SCHEDULE,rowId,System.currentTimeMillis() / 1000);     }

单元测试

/**  * Created by patterncat on 2016-02-11.  */ public class ShoppingServiceTest extends RedisdemoApplicationTests{      @Autowired     ShoppingService shoppingService;      @Autowired     RedisTemplate redisTemplate;      @Test     public void loginCookies() throws InterruptedException {         System.out.println("/n----- testLoginCookies -----");         String token = UUID.randomUUID().toString();          shoppingService.viewItem(token, "username", "itemX");         System.out.println("We just logged-in/updated token: " + token);         System.out.println("For user: 'username'");         System.out.println();          System.out.println("What username do we get when we look-up that token?");         String r = shoppingService.getLgoinUserByToken(token);         System.out.println(r);         System.out.println();         Assert.assertNotNull(r);          System.out.println("Let's drop the maximum number of cookies to 0 to clean them out");         System.out.println("We will start a thread to do the cleaning, while we stop it later");          shoppingService.startCleanSessionTask();          long s = redisTemplate.opsForHash().size(ShoppingService.KEY_LOGIN_USER);         System.out.println("The current number of sessions still available is: " + s);         Assert.assertTrue(s == 0);     }      @Test     public void shoppingCartCookies() throws InterruptedException {         System.out.println("/n----- testShopppingCartCookies -----");         String token = UUID.randomUUID().toString();          System.out.println("We'll refresh our session...");         shoppingService.viewItem(token, "username", "itemX");         System.out.println("And add an item to the shopping cart");         shoppingService.addToCart(token, "itemY", 3);         Map<String,String> r = redisTemplate.opsForHash().entries(shoppingService.formUserCartKey(token));         System.out.println("Our shopping cart currently has:");         for (Map.Entry<String,String> entry : r.entrySet()){             System.out.println("  " + entry.getKey() + ": " + entry.getValue());         }         System.out.println();          Assert.assertTrue(r.size() >= 1);          System.out.println("Let's clean out our sessions and carts");          shoppingService.startCleanSessionTask();          r = redisTemplate.opsForHash().entries(shoppingService.formUserCartKey(token));         System.out.println("Our shopping cart now contains:");         for (Map.Entry<String,String> entry : r.entrySet()){             System.out.println("  " + entry.getKey() + ": " + entry.getValue());         }         Assert.assertTrue(r.size() == 0);     }      @Test     public void cacheRequest(){         System.out.println("/n----- testCacheRequest -----");         String token = UUID.randomUUID().toString();          shoppingService.viewItem(token, "username", "itemX");         String url = "http://test.com/?item=itemX";         System.out.println("We are going to cache a simple request against " + url);         String result = shoppingService.cacheRequest(url, () -> "content for " + url);         System.out.println("We got initial content:/n" + result);         System.out.println();          Assert.assertNotNull(result);          System.out.println("To test that we've cached the request, we'll pass a bad callback");         String result2 = shoppingService.cacheRequest(url, null);         System.out.println("We ended up getting the same response!/n" + result2);          Assert.assertTrue(result.equals(result2));          Assert.assertFalse(shoppingService.canCache("http://test.com/"));         Assert.assertFalse(shoppingService.canCache("http://test.com/?item=itemX&_=1234536"));     }      @Test     public void cacheRows() throws InterruptedException {         System.out.println("/n----- testCacheRows -----");         System.out.println("First, let's schedule caching of itemX every 5 seconds");         shoppingService.scheduleRowCache("itemX", 5);         System.out.println("Our schedule looks like:");         Set<ZSetOperations.TypedTuple> range = redisTemplate.boundZSetOps(ShoppingService.KEY_SCHEDULE).rangeWithScores(0, -1);         for (ZSetOperations.TypedTuple tuple : range){             System.out.println("  " + tuple.getValue() + ", " + tuple.getScore());         }         Assert.assertTrue(range.size() != 0);          System.out.println("We'll start a caching thread that will cache the data...");          shoppingService.startCacheRowTask();          Thread.sleep(1000);         System.out.println("Our cached data looks like:");         String r = (String) redisTemplate.opsForValue().get(shoppingService.formInventoryKey("itemX"));         System.out.println(r);         Assert.assertNotNull(r);         System.out.println();          System.out.println("We'll check again in 5 seconds...");         Thread.sleep(5000);         System.out.println("Notice that the data has changed...");         String r2 = (String) redisTemplate.opsForValue().get(shoppingService.formInventoryKey("itemX"));         System.out.println(r2);         System.out.println();         Assert.assertNotNull(r2);         Assert.assertFalse(r.equals(r2));          System.out.println("Let's force un-caching");         shoppingService.scheduleRowCache("itemX", -1);         Thread.sleep(1000);         r = (String) redisTemplate.opsForValue().get(shoppingService.formInventoryKey("itemX"));         System.out.println("The cache was cleared? " + (r == null));         Assert.assertNull(r);     } }