RedisTemplate访问Redis数据结构（二）——List

Redis列表是简单的字符串列表，按照插入顺序排序。你可以添加一个元素导列表的头部（左边）或者尾部（右边），此处我们使用redisTemplate，配置如下（详情请见链接：RedisTemplate访问Redis数据结构（前言））

<bean id="redisTemplate" class="org.springframework.data.redis.core.RedisTemplate">      <property name="connectionFactory" ref="jedisConnFactory"/>      <property name="keySerializer">        <bean class="org.springframework.data.redis.serializer.StringRedisSerializer"/>    </property>    <property name="hashKeySerializer">        <bean class="org.springframework.data.redis.serializer.StringRedisSerializer"/>    </property>    <property name="valueSerializer">        <bean class="org.springframework.data.redis.serializer.GenericJackson2JsonRedisSerializer"/>    </property>    <property name="hashValueSerializer">        <bean class="org.springframework.data.redis.serializer.GenericJackson2JsonRedisSerializer"/>    </property></bean> 

RedisTemplate使用ListOperations专门操作list列表。首先初始化spring工厂获得redisTemplate和opsForList

    private RedisTemplate<String,Object> redisTemplate;    private ListOperations<String, Object> opsForList;    @SuppressWarnings("unchecked")    @Before    public void before(){        @SuppressWarnings("resource")        ApplicationContext context = new ClassPathXmlApplicationContext("/applicationContext.xml");        redisTemplate = (RedisTemplate<String,Object>)context.getBean("redisTemplate");        opsForList = redisTemplate.opsForList();    }

使用Junit4测试工具进行演示

Long leftPush(K key, V value);

List range(K key, long start, long end);

    @Test    public void  testLeftPush(){        redisTemplate.delete("li1");        //先进后出(左进左出)        opsForList.leftPush("li1", "a");        opsForList.leftPush("li1", "b");        opsForList.leftPush("li1", "c");        List<Object> range = opsForList.range("li1", 0, -1);        for (Object object : range) {            System.out.println(object);//c b a        }        opsForList.leftPush("li1", "d");        opsForList.leftPush("li1", "e");        opsForList.leftPush("li1", "f");        List<Object> range1 = opsForList.range("li1", 0, -1);        for (Object object : range1) {            System.out.println(object);//f e d c b a        }    }

void trim(K key, long start, long end);

    @Test    public void testTrim(){        redisTemplate.delete("li2");        opsForList.leftPush("li2", "a");        opsForList.leftPush("li2", "b");        opsForList.leftPush("li2", "c");        opsForList.trim("li2", 1, -1);        List<Object> range = opsForList.range("li2", 0, -1);        for (Object object : range) {            System.out.println(object);//b a        }    }

Long size(K key);

    @Test    public void testSize(){        redisTemplate.delete("li3");        System.out.println(opsForList.size("li3"));//0        opsForList.leftPush("li3", "a");        System.out.println(opsForList.size("li3"));//1    }

Long leftPushAll(K key, V… values);

    @Test    public void testLeftPushAll(){        redisTemplate.delete("li4");        opsForList.leftPushAll("li4", "a","b","c");        System.out.println(opsForList.size("li4"));//3        List<Object> param = new ArrayList<Object>();        param.add("d");        param.add("e");        param.add("f");        opsForList.leftPushAll("li4", param);        System.out.println(opsForList.size("li4"));//6        opsForList.leftPushAll("li4", new Object[]{"g","h"});        System.out.println(opsForList.size("li4"));//8        List<Object> range = opsForList.range("li4", 0, -1);        for (Object object : range) {            System.out.println(object);//h g f e d c b a        }        opsForList.leftPush("li4", param);        System.out.println(opsForList.size("li4"));//9        opsForList.leftPush("li4", new Object[]{"g","h"});        System.out.println(opsForList.size("li4"));//10        List<Object> range1 = opsForList.range("li4", 0, -1);        for (Object object : range1) {            System.out.println(object);            /*                [Ljava.lang.Object;@6d06654b                [d, e, f]                h                g                f                e                d                c                b                a              */        }    }

Long leftPushAll(K key, Collection values);

    @Test    public void testLeftPushAllCollection(){        redisTemplate.delete("li5");        List<Object> strs = new ArrayList<Object>();        strs.add("a");        strs.add("b");        strs.add("c");        opsForList.leftPushAll("li5", strs);        List<Object> range = opsForList.range("li5", 0, -1);        for (Object object : range) {            System.out.println(object);//c b a        }    }

Long leftPushIfPresent(K key, V value);

    @Test    public void testLeftPushIfPresent(){        redisTemplate.delete("li6");        opsForList.leftPushIfPresent("li6", "a");        System.out.println(opsForList.size("li6"));//0        opsForList.leftPush("li6", "a");        opsForList.leftPushIfPresent("li6", "b");        System.out.println(opsForList.size("li6"));//2    }

Long rightPush(K key, V value);

    @Test    public void testRightPush(){        redisTemplate.delete("li7");        //先进先出(右进左出)        opsForList.rightPush("li7", "a");        opsForList.rightPush("li7", "b");        opsForList.rightPush("li7", "c");        List<Object> range = opsForList.range("li7", 0, -1);        for (Object object : range) {            System.out.println(object);//a b c        }    }

Long rightPushAll(K key, V… values);

    @Test    public void testRightPushAll(){        redisTemplate.delete("li8");        opsForList.rightPushAll("li8", "a","b","c");        List<Object> range = opsForList.range("li8", 0, -1);        for (Object object : range) {            System.out.println(object);//a b c        }    }

Long rightPushAll(K key, Collection values);

    @Test    public void testRightPushAllCollection(){        redisTemplate.delete("li9");        List<Object> param = new ArrayList<Object>();        param.add("a");        param.add("b");        param.add("c");        opsForList.rightPushAll("li9", param);        List<Object> range = opsForList.range("li9", 0, -1);        for (Object object : range) {            System.out.println(object);//a b c        }    }

Long rightPushIfPresent(K key, V value);

    @Test    public void testRightPushIfPresent(){        redisTemplate.delete("li10");        opsForList.rightPushIfPresent("li10", "a");        System.out.println(opsForList.size("li10"));//0        opsForList.rightPush("li10", "a");        opsForList.rightPushIfPresent("li10", "b");        System.out.println(opsForList.size("li10"));//2    }

Long rightPush(K key, V pivot, V value);

    @Test    public void testRightPushPivot(){        redisTemplate.delete("li11");        //把value值放到key对应列表中pivot值的右面，如果pivot值存在的话        opsForList.rightPush("li11", "a","b");        System.out.println(opsForList.size("li11"));//0        opsForList.rightPush("li11", "a");        opsForList.rightPush("li11", "a","b");        List<Object> range = opsForList.range("li11", 0, -1);        for (Object object : range) {            System.out.println(object);//a b        }    }

void set(K key, long index, V value);

    @Test    public void testSetThrowExc1(){        redisTemplate.delete("li12");        opsForList.rightPush("li12", "a");        opsForList.set("li12", 2, "h");//ERR INDEX OUT OF RANGE    }

    @Test    public void testSetThrowExc2(){        redisTemplate.delete("li13");        opsForList.set("li13", 2, "a");//ERR NO SUCH KEY    }

    @Test    public void testSet(){        redisTemplate.delete("li14");        opsForList.rightPush("li14", "a");        System.out.println(opsForList.range("li14", 0, -1));//[a]        opsForList.set("li14", 0, "b");        System.out.println(opsForList.range("li14", 0, -1));//[b]    }

Long remove(K key, long count, Object value);

    @Test    public void testRemove(){        redisTemplate.delete("li15");        opsForList.rightPush("li15", "a");        opsForList.rightPush("li15", "b");        opsForList.rightPush("li15", "c");        opsForList.rightPush("li15", "b");        opsForList.rightPush("li15", "a");        opsForList.remove("li15", 1, "b");//将删除列表中存储在列表中第一次出现的"b"        List<Object> list = opsForList.range("li15", 0, -1);        for (Object object : list) {            System.out.println(object);//a c b a        }    }

V index(K key, long index);

    @Test    public void testIndex(){        redisTemplate.delete("li16");        opsForList.rightPush("li16", "a");        opsForList.rightPush("li16", 1);        opsForList.rightPush("li16", new User());        opsForList.rightPush("li16", "c");        opsForList.rightPush("li16", "b");        Object index = opsForList.index("li16", 2);        System.out.println(index);//结果：User [id=null, username=null, password=null]    }

V leftPop(K key);

    @Test    public void testLeftPop(){        redisTemplate.delete("li17");        opsForList.rightPush("li17", 1);        opsForList.rightPush("li17", 2);        opsForList.rightPush("li17", 3);        opsForList.leftPop("li17");        List<Object> range = opsForList.range("li17", 0, -1);        for (Object object : range) {            System.out.println(object);//结果：2 3        }    }

V leftPop(K key, long timeout, TimeUnit unit);

    @Test    public void testLeftPopTimeout(){        //弹出队列最左边的元素，如果没有则保持线程，等有了再弹出，设有超时时间，当过了超时时间，则线程终止        opsForList.leftPop("li18",5,TimeUnit.SECONDS);    }

V rightPopAndLeftPush(K sourceKey, K destinationKey);

    @Test    public void testRightPopAndLeftPush(){        //从一个队列的右边弹出一个元素并将这个元素放入另一个指定队列的最左边        redisTemplate.delete("li18");        redisTemplate.delete("li19");        opsForList.rightPushAll("li18", "a","b","c");        opsForList.rightPopAndLeftPush("li18", "li19");        List<Object> range = opsForList.range("li18", 0, -1);        for (Object object : range) {            System.out.println(object);//结果：a b        }        List<Object> range1 = opsForList.range("li19", 0, -1);        for (Object object : range1) {            System.out.println(object);//结果：c        }    }

这里用一个形象的故事来呈现该API的具体场景，同学们可以复制源代码粘贴到自己的电脑上运行玩一下

V rightPopAndLeftPush(K sourceKey, K destinationKey, long timeout, TimeUnit unit);

    @Test    public void testRightPopAndLeftPushTimeOut(){        //与RightPopAndLeftPush相似，只是添加了超时机制        //下面用一个简单的小故事呈现一下超时机制        redisTemplate.delete("li20");        redisTemplate.delete("li21");        try {            System.out.println("一天，li21来找li20还钱。");            Thread.sleep(3000);            System.out.println("但是li20当时身上所有资产的个数为："+opsForList.size("li20")+"个，怎么可能有钱还");            Thread.sleep(5000);            System.out.println("而此时li21身上的资产个数为"+opsForList.size("li21")+"个，他一分钱都没有，他是真的缺钱！");            Thread.sleep(5000);            System.out.println("li20让li21等一会儿试试，也许某个傻逼程序员会施舍个东西给他，到时候就拿那个东西给li21还债！li21决定等上5秒试试。");            Thread.sleep(7000);            Runnable runnable = new Runnable() {                @Override                public void run() {                    for(int i = 5;i>0;i--){                        try {                            Thread.sleep(1000);                            System.out.println(i);                        } catch (InterruptedException e) {                            e.printStackTrace();                        }                    }                }            };            Thread thread = new Thread(runnable);            thread.start();            opsForList.rightPopAndLeftPush("li20", "li21", 5, TimeUnit.SECONDS);            Thread.sleep(1000);            System.out.println("5秒后，li21什么都没等到。此时li21的资产个数为："+opsForList.size("li21")+"个，li20的资产个数为："+opsForList.size("li20")+"个。li20让他再等15秒试试。li21答应了！");            Thread.sleep(7000);            Runnable runnable1 = new Runnable() {                @Override                public void run() {                    for(int i = 15;i>0;i--){                        try {                            Thread.sleep(1000);                            if(i==11){                                System.out.println("果真，还没到15秒，傻逼程序员真来了！还塞给了li20一个a");                                Thread.sleep(5000);                                opsForList.rightPush("li20", "a");                                System.out.println("这个时候，li20把他唯一一个元素a给了li21");                                return;                            }else{                                System.out.println(i);                            }                        } catch (InterruptedException e) {                            e.printStackTrace();                        }                    }                }            };            Thread thread1 = new Thread(runnable1);            thread1.start();            opsForList.rightPopAndLeftPush("li20", "li21", 20, TimeUnit.SECONDS);            Thread.sleep(5000);            System.out.println("现在li20身上的元素有"+opsForList.size("li20")+"个，而li21得到了"+opsForList.range("li21", 0, 0)+",资产变成了"+opsForList.size("li21")+"个！");            Thread.sleep(5000);            System.out.println("现在li20又变得一贫如洗了，当然，可以看出，他是一个言而有信的人！li20心想：傻逼程序员真的是傻逼程序员！");        } catch (InterruptedException e) {            e.printStackTrace();        }    }

RedisTemplate访问Redis数据结构（前言）
RedisTemplate访问Redis数据结构（一）——String
RedisTemplate访问Redis数据结构（二）——List
RedisTemplate访问Redis数据结构（三）——Hash
RedisTemplate访问Redis数据结构（四）——Set
RedisTemplate访问Redis数据结构（五）——ZSet