1. Add cache
After adding redis cache, the database will not be refreshed all the time, reducing database pressure
pom.xml dependencies
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-cache</artifactId>
</dependency>
SpringbootApplication
@EnableCaching
EchartsController
@AuthAccess
@GetMapping("/file/front/all")
@Cacheable(value = "files", key = "targetClass + methodName")
public Result frontAll() {
return Result.success(fileMapper.selectList(null));
}
You can also customize the key, enclosed in ' '
@AuthAccess
@GetMapping("/file/front/all")
@Cacheable(value = "files", key = "'frontAll'")
public Result frontAll() {
return Result.success(fileMapper.selectList(null));
}
2. Update the cache:
fileController
//更新
@PostMapping("/update")
//更新缓存
@CachePut(value = "files",key = "'frontAll'")
public Result update(@RequestBody Files files) {
//新增或修改
fileMapper.updateById(files);
return success(fileMapper.selectList(null));
}
3. Delete the cache
After the database is deleted, the first cache is also deleted, and the database will not be requested later
//删除
@DeleteMapping("/{id}")
//清除一条缓存,key为要清空的数据
@CacheEvict(value = "emp",key = "'frontAll'")
public Result delete(@PathVariable("id") Integer id) {
Files files = fileMapper.selectById(id);
files.setIsDelete(true);
fileMapper.updateById(files);
return success();
}
4. Integrate redis
pom.xml
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-redis</artifactId>
</dependency>
application.yml
redis:
port: 6379
host: 127.0.0.1
EchartController
@Resource
private FileMapper fileMapper;
@Autowired
private StringRedisTemplate stringRedisTemplate;
@AuthAccess
@GetMapping("/file/front/all")
/*@Cacheable(value = "files", key = "targetClass + methodName")*/
public Result frontAll() {
//1.从缓存获取数据
String jsonStr = stringRedisTemplate.opsForValue().get(FILES_KEY);
List<Files> files;
//2.取出来的json是空的
if (StrUtil.isBlank(jsonStr)) {
//3.从数据库取出数据
files = fileMapper.selectList(null);
//4.再去缓存到redis
stringRedisTemplate.opsForValue().set(FILES_KEY,JSONUtil.toJsonStr(files));
} else {
//减轻数据库的压力
//5.如果有,从redis缓存中获取数据
files = JSONUtil.toBean(jsonStr, new TypeReference<List<Files>>() {
}, true);
}
return Result.success(files);
}
After operating the database update cache operation: (used when adding, deleting, and modifying)
The first method: the easiest way
//最简单的方式
flushRedis(Constants.FILES_KEY);
delete cache
FileController
@Autowired
private StringRedisTemplate stringRedisTemplate;
//删除缓存
private void flushRedis(String key){
stringRedisTemplate.delete(key);
}
//更新
@PostMapping("/update")
//更新缓存
/*@CachePut(value = "files",key = "'frontAll'")*/
public Result update(@RequestBody Files files) {
//新增或修改
fileMapper.updateById(files);
flushRedis(Constants.FILES_KEY);
return success();
}
//删除
@DeleteMapping("/{id}")
//清除一条缓存,key为要清空的数据
/* @CacheEvict(value = "emp",key = "'frontAll'")*/
public Result delete(@PathVariable("id") Integer id) {
Files files = fileMapper.selectById(id);
files.setIsDelete(true);
fileMapper.updateById(files);
flushRedis(Constants.FILES_KEY);
return success();
}
The second method:
set cache
FileController
//设置缓存
private void setCache(String key,String value){
stringRedisTemplate.opsForValue().set(key,value);
}
① Take out the data from redis, set it up after the operation, no need to query the database, and the performance is relatively high
//从redis取出数据,操作完,再设置,不用查询数据库
String json = stringRedisTemplate.opsForValue().get(Constants.FILES_KEY);
List<Files> files1 = JSONUtil.toBean(json, new TypeReference<List<Files>>() {
},true);
files1.add(saveFile);
setCache(Constants.FILES_KEY,JSONUtil.toJsonStr(files1));
② Find the data from the database, and then set the latest cache
//从数据库查出数据
List<Files> files = fileMapper.selectList(null);
//设置最新的缓存
setCache(Constants.FILES_KEY, JSONUtil.toJsonStr(files));