1.Spring是如何集成Redis的？
Spring Data Redis
引入依赖
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-redis</artifactId>
</dependency>
<dependency>
<groupId>org.apache.commons</groupId>
<artifactId>commons-pool2</artifactId>
</dependency>
2.高级封装
3.Redis配置
#Redis服务器地址
spring.redis.host=192.168.11.84
#Redis连接端口
spring.redis.port=6379
#Redis数据库索引(默认为0)
spring.redis.database=0
#Redis服务器的连接密码默认为空
spring.redis.password=
#连接超时时间
spring.redis.timeout=30000
#连接池最大的连接数(使用负值表示没有限制)默认为8
spring.redis.lettuce.pool.max-active=8
# 连接池中的最大空闲连接 默认 8
spring.redis.lettuce.pool.max-idle=8
# 连接池中的最小空闲连接 默认 0
spring.redis.lettuce.pool.min-idle=1
#连接池中最大空闲等待时间，3s没有活干的时候直接驱逐该链接
spring.redis.lettuce.pool.time-between-eviction-runs=3000
# 连接池最大阻塞等待时间（使用负值表示没有限制） 默认 -1
spring.redis.lettuce.pool.max-wait=-1
4.StringRedisTemplate
String
@SpringBootTest
class StringTests {
@Autowired
StringRedisTemplate stringRedisTemplate;
@Resource(name="redisTemplate")
RedisTemplate<String,Student> redisTemplate;
@Test
public void test3() {
Student student = Student.builder().id(1).name("海洋").build();
redisTemplate.opsForValue().set("student.1",student);
// stringRedisTemplate.opsForValue().set("Student."+student.getId(), JSONUtil.toJsonStr(student));
Student student1 = redisTemplate.opsForValue().get("student.1");
System.out.println(student1);
}
@Test //设置过期时间
public void test(){
// stringRedisTemplate.opsForValue().set("海洋","帅呆了",30, TimeUnit.SECONDS);
stringRedisTemplate.opsForValue().set("海洋","帅呆了",Duration.ofSeconds(30));
String s = stringRedisTemplate.opsForValue().get("海洋");
System.out.println(s);
}
@Test //setnx(锁的竞争)
public void test1() {
Boolean haiyang = stringRedisTemplate.opsForValue().setIfAbsent("haiyang", "88");
}
@Test
public void test2() {
Long haiyang = stringRedisTemplate.opsForValue().increment("haiyang");
Long haiyang1 = stringRedisTemplate.opsForValue().increment("haiyang", 20);
Long haiyang2 = stringRedisTemplate.opsForValue().decrement("haiyang", 50);
}
@Test
public void test4() {
stringRedisTemplate.opsForValue().append("haiyang","酷");
}
}
Hash
package com.by;
import com.by.model.Product;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.data.redis.core.StringRedisTemplate;
import javax.annotation.Resource;
import java.util.List;
import java.util.Map;
import java.util.Set;
@SpringBootTest
class HashTests {
@Autowired
StringRedisTemplate stringRedisTemplate;
@Resource(name="redisTemplate")
RedisTemplate<String, Product> redisTemplate;
@Test
public void test(){
redisTemplate.opsForHash().put("手机","name","小米");
redisTemplate.opsForHash().put("手机","age","6个月");
Product product = Product.builder().id(1).name("手机").build();
redisTemplate.opsForHash().put("手机","小米品牌手机",product);
}
@Test
public void test1(){
Object o = redisTemplate.opsForHash().get("手机", "name");
System.out.println(o);
}
@Test
public void test2(){
Boolean aBoolean = redisTemplate.opsForHash().hasKey("手机", "name");
Map<Object, Object> entries = redisTemplate.opsForHash().entries("手机");//key和value同时获取
}
@Test
public void test3(){
Set<Object> objects = redisTemplate.opsForHash().keys("手机");
}
@Test
public void test4(){
List<Object> values = redisTemplate.opsForHash().values("手机");
}
@Test
public void test5(){
Product product1 = Product.builder().id(1).name("小米手机").build();
Product product2 = Product.builder().id(1).name("华为手机").build();
redisTemplate.opsForHash().put("黑名单",String.valueOf(1),product1);
redisTemplate.opsForHash().put("黑名单",String.valueOf(2),product2);
}
}
List
@SpringBootTest
class ListTests {
@Autowired
StringRedisTemplate stringRedisTemplate;
@Resource(name="redisTemplate")
RedisTemplate<String, Product> redisTemplate;
@Test
public void test(){
Product oppo1 = Product.builder().id(1).name("OPPO").build();
Product oppo2 = Product.builder().id(2).name("OPPOX").build();
redisTemplate.opsForList().leftPushAll("OPPO手机",oppo1,oppo2);
}
@Test
public void test1(){
Product oppo3 = Product.builder().id(3).name("OPPOB").build();
redisTemplate.opsForList().leftPush("OPPO手机",oppo3);
}
@Test
public void test2(){
redisTemplate.opsForList().leftPop("OPPO手机");
}
@Test
public void test3(){
redisTemplate.opsForList().rightPop("OPPO手机");
}
@Test
public void test4(){
Product product = redisTemplate.opsForList().index("OPPO手机", 0);
System.out.println(product);
}
@Test
public void test5(){
Long size = redisTemplate.opsForList().size("OPPO手机");
System.out.println(size);
}
@Test
void test6() {
// 如果一些原生命令，spring 没有给我们封装，redisTemplate.execute（new RedisCallback）
while (true){
System.out.println("开始一轮监听");
List<byte[]> rawResults = redisTemplate.execute(new RedisCallback<List<byte[]>>() {
@Override
public List<byte[]> doInRedis(RedisConnection connection) throws DataAccessException {
return connection.bRPop(10,"OPPO手机".getBytes());
}
});
if(ObjUtil.isNotEmpty(rawResults)){
byte[] rawKey = rawResults.get(0);
byte[] rawValue = rawResults.get(1);
Product product = (Product)redisTemplate.getValueSerializer().deserialize(rawValue);
System.out.println(product);
}
}
}
}Set
package com.by;
import cn.hutool.core.util.ObjUtil;
import com.by.model.Product;
import com.by.model.Student;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.dao.DataAccessException;
import org.springframework.data.redis.connection.RedisConnection;
import org.springframework.data.redis.core.RedisCallback;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.data.redis.core.SetOperations;
import org.springframework.data.redis.core.StringRedisTemplate;
import javax.annotation.Resource;
import java.util.List;
import java.util.Set;
@SpringBootTest
class SetTests {
@Autowired
StringRedisTemplate stringRedisTemplate;
@Resource(name="redisTemplate")
SetOperations<String, Student> setOperations;
@Test//取差集
void test(){
stringRedisTemplate.opsForSet().add("海洋","语文","数学","英语","品德");
stringRedisTemplate.opsForSet().add("洋洋","语文","数学","英语","美术");
Set<String> difference = stringRedisTemplate.opsForSet().difference("海洋", "甜甜");
}
@Test//取交集
void test1(){
stringRedisTemplate.opsForSet().add("海洋","语文","数学","英语","品德");
stringRedisTemplate.opsForSet().add("洋洋","语文","数学","英语","美术");
Set<String> intersect = stringRedisTemplate.opsForSet().intersect("海洋", "甜甜");
}
@Test//取交集
void test2(){
stringRedisTemplate.opsForSet().add("海洋","语文","数学","英语","品德");
stringRedisTemplate.opsForSet().add("洋洋","语文","数学","英语","美术");
Set<String> union = stringRedisTemplate.opsForSet().union("海洋", "甜甜");
}
}
Zset
@SpringBootTest
class ZSetTests {
@Autowired
StringRedisTemplate stringRedisTemplate;
@Resource(name="redisTemplate")
SetOperations<String, Student> setOperations;
@Test
void test(){
stringRedisTemplate.opsForZSet().add("海洋","语文",80);
stringRedisTemplate.opsForZSet().add("海洋","英语",60);
stringRedisTemplate.opsForZSet().add("海洋","数学",70);
Long aLong = stringRedisTemplate.opsForZSet().size("海洋");
Long aLong1 = stringRedisTemplate.opsForZSet().removeRangeByScore("海洋", 60, 100);
}
@Test
void test1(){
stringRedisTemplate.opsForZSet().add("海洋","语文",80);
stringRedisTemplate.opsForZSet().add("海洋","英语",60);
stringRedisTemplate.opsForZSet().add("海洋","数学",70);
Set<String> range1 = stringRedisTemplate.opsForZSet().range("海洋", 0,-1);
Set<ZSetOperations.TypedTuple<String>> tuples = stringRedisTemplate.opsForZSet().rangeByScoreWithScores("海洋", 60, 100);
Set<ZSetOperations.TypedTuple<String>> typedTuples = stringRedisTemplate.opsForZSet().reverseRangeByScoreWithScores("海洋", 50, 100);//正序排列
}
@Test //模拟新闻点击量，排名
void test2(){
String key ="product.hot";
ArrayList<Integer> productId = CollUtil.newArrayList(1, 2, 3, 4, 5, 6, 7, 8, 9, 10);//使用hutool中的工具，获取先的数组
ExecutorService executorService = Executors.newFixedThreadPool(100);//jdk自带的线程池
for (int i = 1; i <=100; i++) {
executorService.submit(()->{
int c = RandomUtil.randomInt(1, 11);//RandomUtil.randomInt 获得指定范围内的随机数,例如我们想产生一个[10, 100)的随机数
System.out.println("访问了"+c);
stringRedisTemplate.opsForZSet().incrementScore(key,String.valueOf(c),1);//每次访问,数据加一
});
}
//因为是异步的，避免冲突
ThreadUtil.safeSleep(5000);
Set<String> strings = stringRedisTemplate.opsForZSet().reverseRange(key, 0, -1);
}
}BitMap
@SpringBootTest
class BitMapTests {
@Autowired
StringRedisTemplate stringRedisTemplate;
@Resource(name="redisTemplate")
RedisTemplate<String, Student> redisTemplate;
private String key = "sing.2024.haiyang";
@Test //签到
void test(){
Boolean b = stringRedisTemplate.opsForValue().setBit(key, 10, true);//设置某一天的偏移量，表示第10天的偏移量为1
b = stringRedisTemplate.opsForValue().setBit(key, 30, true);
b = stringRedisTemplate.opsForValue().setBit(key, 56, true);
RedisCallback<Long> redisCallback = new RedisCallback<Long>() {
@Override
public Long doInRedis(RedisConnection connection) throws DataAccessException {
return connection.bitCount(key.getBytes());
}
};
Long execute = redisTemplate.execute(redisCallback);
}
@Test //车展,统计总的人数和这三天都来的人数
void test1() {
String key1 = "2024.3.28";
String key2 = "2024.3.29";
String key3 = "2024.3.30";
int yangyang = 10, tiantian = 20, tangtang = 40;
//第一天
stringRedisTemplate.opsForValue().setBit(key1, yangyang, true);
stringRedisTemplate.opsForValue().setBit(key1, tangtang, true);
//第二天
stringRedisTemplate.opsForValue().setBit(key2, yangyang, true);
stringRedisTemplate.opsForValue().setBit(key2, tiantian, true);
stringRedisTemplate.opsForValue().setBit(key2, tangtang, true);
//第三天
stringRedisTemplate.opsForValue().setBit(key3, yangyang, true);
stringRedisTemplate.opsForValue().setBit(key3, tangtang, true);
//Q1统计一共来了多少人
String q1 = "q1";
RedisCallback<Long> redisCallback = connection -> {
return connection.bitOp(RedisStringCommands.BitOperation.OR, q1.getBytes(), key1.getBytes(), key2.getBytes(), key3.getBytes());
};
//将三天的key合并值放到q1的key中
Long aLong = redisTemplate.execute(redisCallback);
RedisCallback<Long> redisCallback2 = connection -> {
return connection.bitCount(q1.getBytes());
};
//求q1里面1的总和
Long execute = redisTemplate.execute(redisCallback2);
//Q2：统计每天都来的人数
String q2="q2";
redisCallback = connection -> {
return connection.bitOp(RedisStringCommands.BitOperation.AND, q2.getBytes(), key1.getBytes(), key2.getBytes(), key3.getBytes());
};
//将三天的key合并值放到q1的key中
Long aLong1 = redisTemplate.execute(redisCallback);
redisCallback2 = connection -> {
return connection.bitCount(q2.getBytes());
};
//求q1里面1的总和
execute = redisTemplate.execute(redisCallback2);
}
}
5.RedisTemplate
5.1乱码的问题
JdkSerializationRedisSerializer serializer = new JdkSerializationRedisSerializer();
byte[] serialize = serializer.serialize("user#01");
System.out.println(new String(serialize));5.2自定义序列化工具(RedisTemplate)配置类
@Configuration
public class RedisConfig {
@Bean //主动注册了一个名字为redisTemplate的bean
public RedisTemplate<Object, Object> redisTemplate(RedisConnectionFactory redisConnectionFactory){
RedisTemplate<Object, Object> template = new RedisTemplate();
template.setConnectionFactory(redisConnectionFactory);
Jackson2JsonRedisSerializer jackson = new Jackson2JsonRedisSerializer(Object.class);
ObjectMapper mapper = new ObjectMapper();
//启用默认类型推理,将类型信息作为属性写入json
//就是把类型的全类名写入JSON
mapper.activateDefaultTyping(mapper.getPolymorphicTypeValidator(),ObjectMapper.DefaultTyping.NON_FINAL);
jackson.setObjectMapper(mapper);
template.setKeySerializer(RedisSerializer.string());
template.setValueSerializer(jackson);
template.setHashKeySerializer(RedisSerializer.string());
template.setHashValueSerializer(jackson);
return template;
}
}SetNX(分布式锁)
@SpringBootTest
class SetNXTests {
@Autowired
StringRedisTemplate stringRedisTemplate;
@Resource(name="redisTemplate")
ValueOperations<String, String> valueOperations;
@Test
void test(){
ExecutorService executorService = Executors.newFixedThreadPool(5);
for (int i = 1; i <=5; i++) {
executorService.execute(()->{
//某一个工人
String ioId="IO"+ RandomUtil.randomInt(1,1000);
while (true){
Boolean b = valueOperations.setIfAbsent("lock.product.1", ioId + " : " + DateUtil.now());
if (b){
System.out.println(Thread.currentThread().getId()+"获得了分布式锁======");
//执行业务
ThreadUtil.safeSleep(3000);
//执行业务成功后
stringRedisTemplate.delete("lock.product.1");
System.out.println(Thread.currentThread().getId()+"释放了分布式锁++++++++");
break;
}else {
System.out.println(Thread.currentThread().getId()+"没有获得分布式锁-------------");
ThreadUtil.safeSleep(3000);
}
}
});
}
ThreadUtil.safeSleep(100000);
}LuaTest
在Redis中使用lua脚本，主要是其能够使多条redis语句具有原子性，在处理订单模块具有重要作用
-
参数说明：
KEYS[]数组用于在脚本中引用传入的键名。ARGV[]数组用于传递额外的参数（非键名）给脚本。redis.call()函数在脚本内部调用Redis命令。
@SpringBootTest
class LuaTests {
@Autowired
StringRedisTemplate stringRedisTemplate;
@Resource(name="redisTemplate")
RedisTemplate<String, Student> redisTemplate;
@Test
void test(){
String lua = "return redis.call('set',KEYS[1],ARGV[1])";
RedisScript<String> redisScript = RedisScript.of(lua, String.class);
stringRedisTemplate.execute(redisScript, CollUtil.newArrayList("a"),"b100");
}
@Test
void test1(){
for (int i = 1; i <= 5; i++) {
stringRedisTemplate.opsForValue().set("product."+i,String.valueOf(i));
}
}
@Test //一次扣减一个库存商品
void test2(){
StringBuilder sb = new StringBuilder();
sb.append( " local key = KEYS[1] " );//你要扣减的key,例如：product.1
sb.append( " local qty = ARGV[1] " );//你要剪得的数量
sb.append( "local redis_qty = redis.call('get',key) " );//查询redis里面存储的数量
sb.append( " if tonumber(redis_qty) >= tonumber(qty) then" ); //库存量与需求量进行对比,tonumber作用是转成数字
sb.append( " redis.call('decrby',key,qty) " ); //对redis数据库进行减操作
sb.append( " return -1 " ); //满足条件，返回-1
sb.append( " else " );
sb.append( " return tonumber(redis_qty) " );//如果不满足，返回库存数量
sb.append( " end " );
RedisScript<Long> redisScript = RedisScript.of(sb.toString(), Long.class);
ExecutorService executorService = Executors.newFixedThreadPool(5);
for (int i = 1; i <= 5; i++) {
executorService.execute(()->{
int qty = RandomUtil.randomInt(1,6);
Long aLong = stringRedisTemplate.execute(redisScript, CollUtil.newArrayList("product.5"), String.valueOf(qty));
if (aLong == -1L) {
System.out.println(Thread.currentThread().getId() + " 扣减成功,扣减了-> "+ qty);
} else {
System.out.println(Thread.currentThread().getId() + "扣减失败，需求量是："+qty+"，剩余库存量："+aLong);
}
});
ThreadUtil.safeSleep(3000);//因为线程是异步的，所以要睡眠一定时间
}
}
@Test //一次扣减多个库存
void test3(){
StringBuilder sb = new StringBuilder();
sb.append( " local table = {} " );//所有不满足的商品都存到table
sb.append( " local values = redis.call('mget', unpack(KEYS)) " );//查询所有的key所含有的value,[product.1,product.2]=>product.1,product.2
sb.append( " for i = 1, #KEYS do " );//循环,#KEYS代表KEYS的值
sb.append( " if tonumber(ARGV[i]) > tonumber(values[i]) then " );//如果需求量大于库存量
sb.append( " table[#table + 1] = KEYS[i] .. '=' .. values[i] " );
sb.append( " end " );
sb.append( " end " );
sb.append( " if #table > 0 then " );//如果有不满足的商品，返回该需求
sb.append( " return table " );
sb.append( " end " );
sb.append( " for i=1 ,#KEYS do " );//如果满足,进行循环扣除
sb.append( " redis.call('decrby',KEYS[i],ARGV[i]) " );
sb.append( " end " );
sb.append( " return{} " );
RedisScript<List> redisScript = RedisScript.of(sb.toString(), List.class);
List<StockProduct> stockProducts =new ArrayList<>();
stockProducts.add(new StockProduct(5,1));
stockProducts.add(new StockProduct(4,2));
List<String> keys = stockProducts.stream().map(it -> "product." + it.getId()).collect(Collectors.toList());
Object[] qtys = stockProducts.stream().map(it -> it.getQty()+"").toArray();
List<String> list = stringRedisTemplate.execute(redisScript, keys, qtys);
if (list.isEmpty()){
System.out.println("库存冻结成功");
}else {
for(String key_qty : list){
String[] split = key_qty.split("=");
System.out.println(split[0]+"库存不足,剩余库存量"+split[1]);
}
}
ThreadUtil.safeSleep(3000);
}
}为什么不使用decyby,decrby具有弊端，以下通过demo进行演示
@Test
void test(){
String key ="product.1";
valueOperations.set(key,5);
ExecutorService executorService = Executors.newFixedThreadPool(5);
for (int i = 1; i <=5; i++) {
executorService.execute(()->{
Integer redis_qty = valueOperations.get(key);
if (redis_qty>=1){
//满足条件，数量减一,但是可能被打断
valueOperations.set(key,redis_qty-1);
System.out.println("线程:"+Thread.currentThread().getId() +"执行成功，数量减一");
}else {
System.out.println("线程:"+Thread.currentThread().getId() +"执行失败");
}
});
}
ThreadUtil.safeSleep(3000);
}
可以看出，定义了product.1的数量为5，线程数为5，正常结果应该为0，但是结果缺为4，这是因为，线程的执行速度非常快，多条线程执行时，库里面显示的都是5，才会造成这种原因。
@Test
void test2(){
String key ="product.1";
valueOperations.set(key,5);
ExecutorService executorService = Executors.newFixedThreadPool(5);
for (int i = 1; i <=8; i++) {
executorService.execute(()->{
Integer redis_qty = valueOperations.get(key);
if (redis_qty>=0){
//满足条件，数量减一,但是可能被打断
Long redis_qty2 = valueOperations.decrement(key);
System.out.println("线程:"+Thread.currentThread().getId() +"执行成功，数量减一");
}else {
System.out.println("线程:"+Thread.currentThread().getId() +"执行失败");
}
});
}
ThreadUtil.safeSleep(3000);
}decrby具有的弊端为，使商品多买，出现负数。
