引入redis缓存+本地缓存示例（Guava实现）

项目结构

流程

先调用本地缓存进行查找，没有查看redis缓存，没有查数据库，同时添加到redis和本地缓存中

代码

StudentServiceImpl

package com.wunaiieq.tmp_redis_20241217.service;

import com.wunaiieq.tmp_redis_20241217.entity.Student;
import com.wunaiieq.tmp_redis_20241217.mapper.StudentMapper;
import lombok.SneakyThrows;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import com.google.common.cache.*;
import org.springframework.data.redis.core.RedisTemplate;


import java.util.concurrent.TimeUnit;


@Service
public class StudentServiceImpl implements StudentService{


    @Autowired
    private StudentMapper studentMapper;
    
    @Autowired
    private RedisService redisService;


    /**
     * 本地缓存
     */
    private LoadingCache<String, Student> Cache = CacheBuilder.newBuilder()
            //设置并发级别为16，并发级别是指可以同时写缓存的线程数
            .concurrencyLevel(16)
            //设置缓存容器的初始容量为1000
            .initialCapacity(1000)
            //设置缓存最大容量为10000，超过10000之后就会按照LRU最近虽少使用算法来移除缓存项
            .maximumSize(10000)
            //设缓存1小时没被使用就过期
            .expireAfterAccess(1, TimeUnit.HOURS)
            //设置要统计缓存的命中率
            .recordStats()
            //设置缓存的移除通知
            .removalListener(new RemovalListener<Object, Object>() {
                @Override
                public void onRemoval(RemovalNotification<Object, Object> notification) {
                    System.out.println(notification.getKey() + " 被移除了，原因： " + notification.getCause());
                }
            })
            .build(new CacheLoader<String, Student>() {
                @Override
                public Student load(String key) throws Exception {
                    // 如果没有缓存先从redis中获取
                    Student student0 = (Student) redisService.get("user:" + key);
                    if (student0 != null) {
                        return student0;
                    }
                    // 2、redis中没有查询数据库
                    Student student = studentMapper.selectById(key);
                    // 4、加入redis分布式缓存
                    redisService.set("student:" + key, student);
                    return student;
                }
            });


    /**
     * 根据用户id查询用户
     *
     * @param id
     * @return
     */
    @SneakyThrows
    @Override
    public Student getById(Long id) {
        // 1、从本地缓存获取
        Student o = Cache.get(id + "");
        return o;
    }
}

RedisService、RedisConfig
博客链接

Controller

package com.wunaiieq.tmp_redis_20241217.controller;

import com.wunaiieq.tmp_redis_20241217.entity.Student;
import com.wunaiieq.tmp_redis_20241217.service.StudentService;
import com.wunaiieq.tmp_redis_20241217.service.StudentServiceImpl;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class Studentcontroller {
    @Autowired
    private StudentServiceImpl studentServiceImpl;
    @GetMapping("/getByid")
    public Student getStudent(long id){
        return studentServiceImpl.getById(id);
    }
}

StudentService

package com.wunaiieq.tmp_redis_20241217.service;

import com.wunaiieq.tmp_redis_20241217.entity.Student;
import lombok.SneakyThrows;

public interface StudentService {
    @SneakyThrows
    Student getById(Long id);
}

StudentMapper

package com.wunaiieq.tmp_redis_20241217.mapper;

import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import com.wunaiieq.tmp_redis_20241217.entity.Student;

public interface StudentMapper extends BaseMapper <Student>{
}