概述

Redis是一款高性能key-value數(shù)據(jù)庫,有豐富的數(shù)據(jù)類型string爬骤、list趴久、hash、set塘辅、zset绝页。

常用的應用場景

緩存荠商、消息隊列、session共享续誉、分布式ID莱没、分布式鎖、關注/點贊酷鸦、排行榜等等,我們這篇主要來講緩存的應用

開始在SpringBoot項目中實踐

redis的安裝本篇不做闡述,后續(xù)可以補充
redis可視化工具可以自行選擇安裝,這里使用Redis Desktop Manager,也可以選擇RedisStudio
本篇在之前JPA的項目基礎上,我們加以改造,加入redis緩存操作

現(xiàn)在pom.xml中加入redis依賴

        <!-- redis 緩存操作 -->
        <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>

在yml配置文件中加入redis配置信息

spring:
  redis:
    database: 0  # Redis數(shù)據(jù)庫索引（默認為0）
    host: localhost # Redis服務器地址
    port: 6379  # Redis服務器連接端口
    password:   # Redis服務器連接密碼（默認為空）
    lettuce:
      pool:
        max-active: 8  # 連接池最大連接數(shù)（使用負值表示沒有限制） 默認 8
        max-wait: -1   # 連接池最大阻塞等待時間（使用負值表示沒有限制） 默認 -1
        max-idle: 8    # 連接池中的最大空閑連接 默認 8
        min-idle: 0    # 連接池中的最小空閑連接 默認 0
  cache:
    type: redis

在SpringBoot2.X,redis默認使用lettuce,基于Netty性能高于以前的jedis饰躲。

創(chuàng)建RedisConfig.java配置類

package com.zhlab.demo.config;

import com.fasterxml.jackson.annotation.JsonAutoDetect;
import com.fasterxml.jackson.annotation.PropertyAccessor;
import com.fasterxml.jackson.databind.ObjectMapper;
import org.springframework.cache.annotation.CachingConfigurerSupport;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.data.redis.connection.RedisConnectionFactory;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.data.redis.serializer.Jackson2JsonRedisSerializer;
import org.springframework.data.redis.serializer.StringRedisSerializer;

/**
 * @ClassName RedisConfig
 * @Description //Redis緩存配置類
 * @Author singleZhang
 * @Email 405780096@qq.com
 * @Date 2020/11/3 0003 下午 2:15
 **/
@Configuration
public class RedisConfig extends CachingConfigurerSupport {

    @SuppressWarnings({ "unchecked", "rawtypes" })
    @Bean
    public RedisTemplate<Object,Object> redisTemplate(RedisConnectionFactory factory) {
        RedisTemplate<Object, Object> template = new RedisTemplate<>();

        // 配置連接工廠
        template.setConnectionFactory(factory);

        Jackson2JsonRedisSerializer jackson2JsonRedisSerializer = new Jackson2JsonRedisSerializer(Object.class);

        ObjectMapper mapper = new ObjectMapper();
        // 指定要序列化的域牙咏，field,get和set,以及修飾符范圍，ANY是都有包括private和public
        mapper.setVisibility(PropertyAccessor.ALL, JsonAutoDetect.Visibility.ANY);
        // 指定序列化輸入的類型嘹裂，類必須是非final修飾的妄壶，final修飾的類，比如String,Integer等會跑出異常
        mapper.enableDefaultTyping(ObjectMapper.DefaultTyping.NON_FINAL);
        jackson2JsonRedisSerializer.setObjectMapper(mapper);

        // 值采用json序列化
        template.setValueSerializer(jackson2JsonRedisSerializer);
        // 使用StringRedisSerializer來序列化和反序列化redis的key值
        template.setKeySerializer(new StringRedisSerializer());
        // 設置hash key 和value序列化模式
        template.setHashKeySerializer(new StringRedisSerializer());
        template.setHashValueSerializer(jackson2JsonRedisSerializer);
        template.afterPropertiesSet();
        return template;
    }

}

DAO層不變,按之前的SysAdminUserRepository.java

public interface SysAdminUserRepository extends JpaRepository<SysAdminUser,Long>, Serializable {
    // 就這么簡單?
    // 對,就這么簡單,什么都不用寫,這是Spring Data JPA 默認幫我們實現(xiàn)了基本的數(shù)據(jù)庫操作
    // 如果需要擴展,可以自定義符合Spring Data JPA規(guī)則的查詢方法寄狼，由框架將其自動解析為SQL
}

Service層中加入緩存注解@CacheConfig丁寄、@Cacheable、@CachePut泊愧、@CacheEvict,SysAdminUserService.java,

package com.zhlab.demo.service;

import com.zhlab.demo.dao.SysAdminUserRepository;
import com.zhlab.demo.model.SysAdminUser;
import com.zhlab.demo.utils.PageVo;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.cache.annotation.CacheConfig;
import org.springframework.cache.annotation.CacheEvict;
import org.springframework.cache.annotation.CachePut;
import org.springframework.cache.annotation.Cacheable;
import org.springframework.data.domain.Page;
import org.springframework.data.domain.PageRequest;
import org.springframework.data.domain.Pageable;
import org.springframework.data.domain.Sort;
import org.springframework.stereotype.Service;

import java.util.List;

/**
 * @ClassName SysAdminUserService
 * @Description //SysAdminUserService
 * @Author singleZhang
 * @Email 405780096@qq.com
 * @Date 2020/10/31 0031 上午 9:45
 **/
@CacheConfig(cacheNames = "users")
@Service
public class SysAdminUserService {

    @Autowired
    SysAdminUserRepository sysAdminUserRepository;

    @Cacheable(key="'user_'+#userId")
    public SysAdminUser findUser(Long userId){
        return sysAdminUserRepository.findById(userId).orElse(null);
    }

    @CachePut(key="'user_'+#result.adminUserId")
    public SysAdminUser save(SysAdminUser user){
        return sysAdminUserRepository.save(user);
    }

    @CacheEvict(key="'user_'+#userId")
    public void deleteUser(Long userId) {
        sysAdminUserRepository.findById(userId).ifPresent(sysAdminUserRepository::delete);
    }
}

接口層,UserController.java 加入增伊磺、刪、查來測試一下

package com.zhlab.demo.controller;

import com.zhlab.demo.model.SysAdminUser;
import com.zhlab.demo.service.SysAdminUserService;
import io.swagger.annotations.ApiOperation;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;

/**
 * @ClassName UserController
 * @Description //用戶接口層
 * @Author singleZhang
 * @Email 405780096@qq.com
 * @Date 2020/10/31 0031 上午 9:43
 **/
@RestController
@RequestMapping("/user")
public class UserController {

    @Autowired
    SysAdminUserService sysAdminUserService;

    

    @ApiOperation(value = "方法名:用戶信息", notes = "獲取用戶信息")
    @GetMapping("/{userId}")
    public SysAdminUser findUser(@PathVariable Long userId){
        return sysAdminUserService.findUser(userId);
    }

    @ApiOperation(value = "方法名:新增用戶", notes = "新增用戶")
    @PostMapping("/add")
    public SysAdminUser addUser(@RequestBody SysAdminUser user){
        return sysAdminUserService.save(user);
    }

    @ApiOperation(value = "方法名:刪除用戶信息", notes = "刪除用戶信息")
    @GetMapping("/delete/{userId}")
    public void deleteUser(@PathVariable Long userId){
        sysAdminUserService.deleteUser(userId);
    }

}

啟動項目,打開http://localhost:8080/swagger-ui.html來調試接口

接口

redisManager中,可以看到現(xiàn)在redis里現(xiàn)在還沒數(shù)據(jù)

redisManager

調試一下查詢userId=1的用戶信息

返回結果

此時查看一下redis中的數(shù)據(jù),已經(jīng)新增了一條緩存數(shù)據(jù)

redis

之后查詢這用戶,數(shù)據(jù)會從緩存中獲取删咱。
新增屑埋、刪除調試方法類同。

9.接下來再增加另一種,通過redisTemplate來操作緩存數(shù)據(jù),修改之前的UserController.java痰滋，

package com.zhlab.demo.controller;

import com.zhlab.demo.model.SysAdminUser;
import com.zhlab.demo.service.SysAdminUserService;
import io.swagger.annotations.ApiOperation;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.data.redis.core.ValueOperations;
import org.springframework.web.bind.annotation.*;

import java.util.concurrent.TimeUnit;

/**
 * @ClassName UserController
 * @Description //用戶接口層
 * @Author singleZhang
 * @Email 405780096@qq.com
 * @Date 2020/10/31 0031 上午 9:43
 **/
@RestController
@RequestMapping("/user")
public class UserController {

    private static final int expireTime = 30;

    @Autowired
    SysAdminUserService sysAdminUserService;

    @Autowired
    RedisTemplate redisTemplate;


    @ApiOperation(value = "方法名:用戶信息", notes = "獲取用戶信息")
    @GetMapping("/{userId}")
    public SysAdminUser findUser(@PathVariable Long userId){

        //從緩存獲取有無這個用戶信息
        SysAdminUser userInfo = getCacheObject("users::user_"+userId);
        if(userInfo == null){
            //沒有,則從數(shù)據(jù)庫查詢
            userInfo =sysAdminUserService.findUser(userId);

            //設置緩存
            setCacheObject("users::user_"+userId,userInfo,expireTime,TimeUnit.MINUTES);
        }
        return sysAdminUserService.findUser(userId);
    }

    @ApiOperation(value = "方法名:新增用戶", notes = "新增用戶")
    @PostMapping("/add")
    public SysAdminUser addUser(@RequestBody SysAdminUser user){
        return sysAdminUserService.save(user);
    }

    @ApiOperation(value = "方法名:刪除用戶信息", notes = "刪除用戶信息")
    @GetMapping("/delete/{userId}")
    public void deleteUser(@PathVariable Long userId){

        sysAdminUserService.deleteUser(userId);
    }


    /**
     * 獲取緩存
     * */
    private <T> T getCacheObject(String key){
        ValueOperations<String, T> operation = redisTemplate.opsForValue();
        return operation.get(key);
    }

    /**
     * 設置緩存
     * */
    private <T> ValueOperations<String, T> setCacheObject(String key, T value, Integer timeout, TimeUnit timeUnit) {
        ValueOperations<String, T> operation = redisTemplate.opsForValue();
        operation.set(key, value, timeout, timeUnit);
        return operation;
    }
}

繼續(xù)來調試/user/{userId}這個接口

接口調試

查看結果

redis

總結

SpringBoot中使用redis緩存的方法就介紹到這兒,需要熟練掌握,因為大型項目中緩存的應用非常廣泛雀彼。

項目地址

https://gitee.com/kaixinshow/springboot-note

返回【Spring Boot學習】目錄

SpringBoot配置并使用Redis緩存服務

SpringBoot配置并使用Redis緩存服務

概述

常用的應用場景

開始在SpringBoot項目中實踐

總結

項目地址