redis是什么?
简略来说redis
是一个开源的应用ANSI C语言编写的内存数据库,应用key-value的数据结构。反对数据长久化到硬盘,反对多种api语言的连贯。通常当做缓存解决。
装置redis
- redis官网:https://redis.io 英语好的看官网,下载linux版本redis
- redis for windows: https://github.com/MicrosoftArchive/redis/releases ,windows版下载到本地间接装置即可应用。
windows版本下载安装实现之后,在services.msc外面能看到redis服务。
springboot集成redis
咱们应用redisson框架集成,新建工程,pom中增加如下依赖:
<dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId></dependency><dependency> <groupId>org.projectlombok</groupId> <artifactId>lombok</artifactId> <optional>true</optional></dependency><!-- https://mvnrepository.com/artifact/org.redisson/redisson --><dependency> <groupId>org.redisson</groupId> <artifactId>redisson</artifactId> <version>3.15.0</version></dependency>
批改application.yml文件,增加redis的配置
spring: redisson: address: redis://127.0.0.1:6379 #redis的地址和端口,默认端口是6379 password: #默认没有交易 database: 0 #Redis默认状况下有16个分片,这里配置具体应用的分片,默认是0 timeout: 10000 #连贯超时工夫(毫秒)
增加配置类,映射yml文件中的属性
@Getter@Setter@Configuration@ConfigurationProperties(prefix = "spring.redisson")//获取yml文件中以spring.redisson结尾的所有数据public class RedissonProperties { //映射yml文件外面的数据 private String address; private String password = null; private int database = 0; private int timeout = 3000;}
减少RedissonClient初始化类:
@Configuration@ConditionalOnClass(RedissonClient.class)//存在RedissonClient才创立该类@ConditionalOnProperty({"spring.redisson.address"})//存在spring.redisson.address配置才创立该类public class RedissonConfig { @Resource private RedissonProperties properties; @Bean(destroyMethod = "shutdown") RedissonClient redissonClient(RedissonProperties properties) throws Exception { Config config = new Config(); SingleServerConfig singleServerConfig = config.useSingleServer(); singleServerConfig .setAddress(properties.getAddress()) .setDatabase(properties.getDatabase()) .setTimeout(properties.getTimeout()); //明码不为空才设置,否则默认yml注入的空串会导致创立redisson不胜利 if(!StringUtils.isEmpty(properties.getPassword())){ singleServerConfig.setPassword(properties.getPassword()); } return Redisson.create(config); }}
好了,自此,筹备工作都做好了,上面就能够编码操作redis的数据了。
@RestController@RequestMapping("demo")public class DemoController { @Resource private RedissonClient redissonClient; public static String MAP_KEY = "MAP"; public static String SET_KEY = "SET"; public static String LIST_KEY = "LIST"; @GetMapping("put") public String put(){ RMap<String, String> map = redissonClient.getMap(MAP_KEY); map.put("a","hello redis"); return "ok"; } @GetMapping("get") public String get(){ RMap<String, String> map = redissonClient.getMap(MAP_KEY); return map.get("a"); }}
先用postman申请http://localhost:8080/demo/put
将数据放进去,而后找一个redis的ide工具(本文用的是redis studio)查看redis中的数据
数据是放进去了,而且应用http://localhost:8080/demo/get
也能将数据拿进去,不过用redis的ide工具怎么那么不形象呢,不难看。。。那是因为你在应用redissonClient的时候没有指定序列化形式。批改代码如下:
RMap<String, String> map = redissonClient.getMap(MAP_KEY, JsonJacksonCodec.INSTANCE);
再试下看看redis studio怎么显示的:
怎么样,清晰了吧。那RMap只能放根本数据对象吗》能不能放自定义对象?建一个dto:
@Datapublic class UserDto implements Serializable { private String username; private Integer age; private Date birthday; private List<String> fav;}
新增rest办法:
@GetMapping("put2")public String put2(){ RMap<String, UserDto> map = redissonClient.getMap(MAP_KEY, JsonJacksonCodec.INSTANCE); UserDto userDto = new UserDto(); userDto.setUsername("张三6"); userDto.setAge(18); userDto.setBirthday(new Date()); userDto.setFav(Arrays.asList("apple","pear")); map.put("userDto",userDto); return "ok";}@GetMapping("get2")public UserDto get2() throws InterruptedException { RMap<String, UserDto> map = redissonClient.getMap(MAP_KEY, JsonJacksonCodec.INSTANCE); UserDto userDto = map.get("userDto"); return userDto;}
按套路出牌,本人postman申请,而后看redis studio的数据:
怎么样,难受了吧,对象都被你存进去了,而且还能从redis外面拿进去本人转换成UserDto对象!!!
好了,以上是RMap对象,上面的list和set我就不细讲解了,间接上代码。
@GetMapping("put3")public String put3(){ RSet<Long> set = redissonClient.getSet(SET_KEY, JsonJacksonCodec.INSTANCE); set.add(System.currentTimeMillis()); return "ok";}@GetMapping("get3")public String get3() throws InterruptedException { RSet<Long> set = redissonClient.getSet(SET_KEY, JsonJacksonCodec.INSTANCE); Iterator<Long> iterator = set.iterator(); String result = ""; while (iterator.hasNext()){ result +=","+iterator.next(); } return result;}@GetMapping("put4")public String put4(){ RList<Long> list = redissonClient.getList(LIST_KEY, JsonJacksonCodec.INSTANCE); list.add(1L); return "ok";}@GetMapping("get4")public String get4() throws InterruptedException { RList<Long> list = redissonClient.getList(LIST_KEY, JsonJacksonCodec.INSTANCE); String result=""; for (Long aLong : list) { result+=aLong; } return result;}
每次都要写JsonJacksonCodec.INSTANCE这个玩意很烦,算了,默认了吧。默认应用JsonJacksonCodec.INSTANCE序列化。那咱们批改下config好了。
@Bean(destroyMethod = "shutdown")RedissonClient redissonClient(RedissonProperties properties) throws Exception { Config config = new Config(); SingleServerConfig singleServerConfig = config.useSingleServer(); singleServerConfig .setAddress(properties.getAddress()) .setDatabase(properties.getDatabase()) .setTimeout(properties.getTimeout()); //明码不为空才设置,否则默认yml注入的空串会导致创立redisson不胜利 if(!StringUtils.isEmpty(properties.getPassword())){ singleServerConfig.setPassword(properties.getPassword()); } //指定默认序列化 Codec codec=(Codec) ClassUtils.forName("org.redisson.codec.JsonJacksonCodec", ClassUtils.getDefaultClassLoader()).newInstance(); config.setCodec(codec); return Redisson.create(config);}
上面来一个不指定序列化的调用redis试试:
@GetMapping("test")public String test(){ RMap<String, UserDto> map = redissonClient.getMap("MAP_KEY"); UserDto userDto = new UserDto(); userDto.setUsername("张三6d"); userDto.setAge(18); userDto.setBirthday(new Date()); userDto.setFav(Arrays.asList("apple","pear")); map.put("userDto",userDto); return "ok";}
还乱码吗?不乱码了吧。
redis的用途远不至于此,还能够设置缓存的数据有效期,多长时间内无效,并且能够监听创立、批改、销毁数据事件,另外还有队列、公布订阅等期待大伙摸索。
总结一句,redis当缓存很好用,然而长久化数据库就算了,他天生不是干那个的!
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