1.缓存问题
- 用户数量多,系统访问量大频繁访问数据库,系统性能下降,用户体验差
2.导入依赖 和配置
<dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-data-redis</artifactId></dependency>
spring: redis:host: 自己的地址password: 自己的密码database: 0port: 6379
3.key序列化配置类
@Configuration
public class RedisConfig extends CachingConfigurerSupport {@Beanpublic RedisTemplate<Object,Object> redisTemplate(RedisConnectionFactory connectionFactory){RedisTemplate<Object,Object> redisTemplate=new RedisTemplate<>();//默认的key序列化器为:JdkSerializationRedisSerializerredisTemplate.setKeySerializer(new StringRedisSerializer());redisTemplate.setHashValueSerializer(new StringRedisSerializer());return redisTemplate;}
}
4.缓存短信验证码
4.1实现思路
1.引入RedisTemplate
2.设置验证码缓存到redis
3.登陆成功删除redis中的验证码
4.2代码
@Slf4j
@RestController
@RequestMapping("/user")
public class UserController {@Autowiredprivate UserService userService;@Autowiredprivate RedisTemplate redisTemplate;/*** 发送手机短信验证码** @param user* @return*/@PostMapping("/sendMsg")public R<String> sendMsg(@RequestBody User user, HttpSession session) {//1.获取手机号String phone = user.getPhone();if (StringUtils.isNotEmpty(phone)) {//2.生成四位的验证码String code = ValidateCodeUtils.generateValidateCode(4).toString();//查看验证码log.info("code={}", code);//3.调用阿里云短信服务完成发送//若要真的发送,执行下面
// SMSUtils.sendMessage("签名","",phone,code);//4.生成的验证码保存到session
// session.setAttribute(phone, code);//优化,将生成的验证码缓存到redis中,有效期5分钟redisTemplate.opsForValue().set(phone, code, 5, TimeUnit.MINUTES);return R.success("发送验证码发送成功");}return R.success("发送失败");}/*** 移动端登录*/@PostMapping("/login")public R<User> login(@RequestBody Map map, HttpSession session) {//1.获取手机号String phone = map.get("phone").toString();//2.获取验证码String code = map.get("code").toString();//3.从Session中获取保存的验证码进行比对
// Object codeInSession = session.getAttribute(phone);//优化:从redis中获取缓存验证码Object codeInSession = redisTemplate.opsForValue().get(phone);//4.如果比对成功,判断手机号是否在用户表中if (codeInSession != null && codeInSession.equals(code)) {//登陆成功LambdaQueryWrapper<User> queryWrapper = new LambdaQueryWrapper<>();queryWrapper.eq(User::getPhone, phone);User user = userService.getOne(queryWrapper);if (user == null) {//新用户//5.如果不在用户表,则自动完成注册user = new User();user.setPhone(phone);user.setStatus(1);userService.save(user);}session.setAttribute("user", user.getId());//优化:如果用户登陆成功,删除redis缓存的验证码redisTemplate.delete(phone);return R.success(user);}return R.error("登陆失败");}
}
4.3测试
已经存到redis中
5.缓存菜品数据
5.1实现思路
1、改造DishController的list方法,先从Redis中获取菜品数据,如果有则直接返回,无需查询数据库;如果没有则查询数据库,并将查询到的菜品数据放入Redis。
2、改造DishController的save和update方法,加入清理缓存的逻辑、
注意:在使用缓存过程中,要注意保证数据库中的数据和缓存中的数据一致,如果数据库中的数据发生变化,需要及时清理缓存数据。
5.2代码风暴
@GetMapping("/list")public R<List<DishDto>> list(Dish dish) {List<DishDto> dishDtoList = null;//动态构造keyString key = "dish_" + dish.getCategoryId() + "_" + dish.getStatus();//1.先从redis中获取缓存数据dishDtoList = (List<DishDto>) redisTemplate.opsForValue().get(key);if (dishDtoList != null) {//2.如果存在,直接返回,无需查询数据库return R.success(dishDtoList);}//3.如果不存在,查询数据库,再缓存到redisLambdaQueryWrapper<Dish> queryWrapper = new LambdaQueryWrapper<>();queryWrapper.eq(dish.getCategoryId() != null, Dish::getCategoryId, dish.getCategoryId());queryWrapper.eq(Dish::getStatus, 1);queryWrapper.orderByDesc(Dish::getSort).orderByAsc(Dish::getUpdateTime);List<Dish> list = dishService.list(queryWrapper);dishDtoList = list.stream().map((item) -> {DishDto dishDto = new DishDto();//拷贝BeanUtils.copyProperties(item, dishDto);Long categoryId = item.getCategoryId();//分类idCategory category = categoryService.getById(categoryId);if (category != null) {String categoryName = category.getName();dishDto.setCategoryName(categoryName);}Long dishId = item.getId();LambdaQueryWrapper<DishFlavor> queryWrapper1 = new LambdaQueryWrapper<>();queryWrapper1.eq(DishFlavor::getDishId, dishId);List<DishFlavor> dishFlavors = dishFlavorService.list(queryWrapper1);dishDto.setFlavors(dishFlavors);return dishDto;}).collect(Collectors.toList());//查询完数据库,在将数据缓存到redisredisTemplate.opsForValue().set(key,dishDtoList,60, TimeUnit.MINUTES);return R.success(dishDtoList);}
5.3测试
再次查询时就是从redis缓存中获取了
5.3更新菜品时删除对应的redis缓存
@PutMapping()public R<String> put(@RequestBody DishDto dishDto) {dishService.updateWithFlavor(dishDto);//清理所有菜品的缓存数据
// Set keys = redisTemplate.keys("dish_*");
// redisTemplate.delete(keys);//精确清理,清理某个分类下面的缓存String key="dish_"+dishDto.getCategoryId()+"_1";redisTemplate.delete(key);return R.success("修改成功");}
5.4添加菜品时删除对应的redis缓存
@PostMapping()public R<String> save(@RequestBody DishDto dishDto) {dishService.saveWithFlavor(dishDto);//清理所有菜品的缓存数据
// Set keys = redisTemplate.keys("dish_*");
// redisTemplate.delete(keys);//精确清理,清理某个分类下面的缓存String key="dish_"+dishDto.getCategoryId()+"_1";redisTemplate.delete(key);return R.success("新增菜品成功");}
6.缓存套餐数据【注解】
- 1、导入Spring Cache和Redis相关maven坐标
- 2、在application.yml中配置缓存数据的过期时间
- 3、在启动类上加入@EnableCaching注解,开启缓存注解功能
- 4、在SetmealController的list方法上加入@Cacheable注解
- 5、在SetmealController的save和delete方法上加入CacheEvict注解
6.1引入依赖
<dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-data-redis</artifactId></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-cache</artifactId></dependency>
6.2开启注解缓存
@Slf4j
@SpringBootApplication
@ServletComponentScan
@EnableTransactionManagement
@EnableCaching //开启注解缓存
public class ProductRuijiApplication {public static void main(String[] args) {SpringApplication.run(ProductRuijiApplication.class, args);log.info("程序启动成功");}
}
6.3查询套餐时加入缓存
@Cacheable(value = "setmealCache",key = "#setmeal.categoryId+'_'+#setmeal.status")@GetMapping("/list")public R<List<Setmeal>> list( Setmeal setmeal) {LambdaQueryWrapper<Setmeal> queryWrapper = new LambdaQueryWrapper<>();queryWrapper.eq(setmeal.getCategoryId() != null, Setmeal::getCategoryId, setmeal.getCategoryId());queryWrapper.eq(setmeal.getStatus() != null, Setmeal::getStatus, setmeal.getStatus());queryWrapper.orderByDesc(Setmeal::getUpdateTime);List<Setmeal> list = setmealService.list(queryWrapper);return R.success(list);}
6.4删除套餐时删除缓存
@CacheEvict(value = "setmealCache",allEntries = true)@DeleteMappingpublic R<String> delete(@RequestParam List<Long> ids) {setmealService.removeWithDish(ids);return R.success("删除套餐成功");}