spring boot 缓存应用实例讲解

女爷i 2023-03-02 10:54 31阅读 0赞

> 最近在做springboot的一个项目，用到缓存做登录验证（这块也可用Redis），学到了一些新知识，想和大家分享一下。

#### 一、创建springboot项目 ####

个人认为创建spring boot项目最快的地方就是访问[spring.io][]官网，从官网创建，里面的一些基础配置都给我们配置好了，直接添加即可。

1.  首先我们通过QUICKSTART进入  
    ![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQ0OTIyMTEz_size_16_color_FFFFFF_t_70]
2.  点击**start.spring.io**，进入springboot的搭建界面，进行配置![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQ0OTIyMTEz_size_16_color_FFFFFF_t_70 1]  
    ![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQ0OTIyMTEz_size_16_color_FFFFFF_t_70 2]
3.  选择成功以后直接下载，下载直接解压，导入maven项目（在这里我用的IDEA工具）![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQ0OTIyMTEz_size_16_color_FFFFFF_t_70 3]
4.  pom.xml中导入依赖内容如下：

<dependencies>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-security</artifactId>
            </dependency>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-thymeleaf</artifactId>
            </dependency>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-web</artifactId>
            </dependency>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-aop</artifactId>
            </dependency>
            <dependency>
                <groupId>org.projectlombok</groupId>
                <artifactId>lombok</artifactId>
                <optional>true</optional>
            </dependency>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-test</artifactId>
                <scope>test</scope>
            </dependency>
            <dependency>
                <groupId>org.springframework.security</groupId>
                <artifactId>spring-security-test</artifactId>
                <scope>test</scope>
            </dependency>
    
            <dependency>
                <groupId>com.baomidou</groupId>
                <artifactId>mybatis-plus-boot-starter</artifactId>
                <version>3.1.0</version>
            </dependency>
            <dependency>
                <groupId>com.baomidou</groupId>
                <artifactId>mybatis-plus-generator</artifactId>
                <version>3.1.0</version>
            </dependency>
            <dependency>
                <groupId>mysql</groupId>
                <artifactId>mysql-connector-java</artifactId>
                <scope>runtime</scope>
            </dependency>
    
            
            <dependency>
                <groupId>com.alibaba</groupId>
                <artifactId>druid-spring-boot-starter</artifactId>
                <version>1.1.10</version>
            </dependency>
            
            <dependency>
                <groupId>org.freemarker</groupId>
                <artifactId>freemarker</artifactId>
            </dependency>
            
            <dependency>
                <groupId>org.apache.commons</groupId>
                <artifactId>commons-lang3</artifactId>
                <version>3.6</version>
            </dependency>
            <dependency>
                <groupId>commons-io</groupId>
                <artifactId>commons-io</artifactId>
                <version>2.5</version>
            </dependency>
            
            <dependency>
                <groupId>com.alibaba</groupId>
                <artifactId>fastjson</artifactId>
                <version>1.2.70</version>
            </dependency>
    
          
            
            
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-devtools</artifactId>
            </dependency>
    
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-webflux</artifactId>
            </dependency>
            <dependency>
                <groupId>org.springframework</groupId>
                <artifactId>spring-messaging</artifactId>
            </dependency>
    
            
            <dependency>
                <groupId>org.webjars</groupId>
                <artifactId>webjars-locator-core</artifactId>
            </dependency>
            <dependency>
                <groupId>org.webjars</groupId>
                <artifactId>sockjs-client</artifactId>
                <version>1.0.2</version>
            </dependency>
            <dependency>
                <groupId>org.webjars</groupId>
                <artifactId>stomp-websocket</artifactId>
                <version>2.3.3</version>
            </dependency>
            <dependency>
                <groupId>org.webjars</groupId>
                <artifactId>bootstrap</artifactId>
                <version>3.3.7</version>
            </dependency>
            <dependency>
                <groupId>org.webjars</groupId>
                <artifactId>jquery</artifactId>
                <version>3.1.0</version>
            </dependency>
            <dependency>
                <groupId>org.springframework.security.oauth</groupId>
                <artifactId>spring-security-oauth2</artifactId>
                <version>2.3.3.RELEASE</version>
            </dependency>
    
        </dependencies>

#### 二、创建数据库表，导入数据库配置，反向生成代码 ####

1.  我设计了一个t\_user表，包括id(主键自增) , use\_name（登录名） , password（密码）![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQ0OTIyMTEz_size_16_color_FFFFFF_t_70 4]
2.  将数据库连接信息以及基础配置加进项目的配置文件中  
    ![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQ0OTIyMTEz_size_16_color_FFFFFF_t_70 5]

spring.datasource.druid.url=jdbc:mysql://localhost:3306/byte_easy?useUnicode=true&characterEncoding=utf-8&serverTimezone=CTT
    spring.datasource.druid.username=root
    spring.datasource.druid.password=root
    spring.datasource.druid.driver-class-name=com.mysql.cj.jdbc.Driver
    # \u521D\u59CB\u5316\u65F6\u5EFA\u7ACB\u7269\u7406\u8FDE\u63A5\u7684\u4E2A\u6570
    spring.datasource.druid.initial-size=5
    # \u6700\u5927\u8FDE\u63A5\u6C60\u6570\u91CF
    spring.datasource.druid.max-active=30 
    # \u6700\u5C0F\u8FDE\u63A5\u6C60\u6570\u91CF
    spring.datasource.druid.min-idle=5
    # \u83B7\u53D6\u8FDE\u63A5\u65F6\u6700\u5927\u7B49\u5F85\u65F6\u95F4\uFF0C\u5355\u4F4D\u6BEB\u79D2
    spring.datasource.druid.max-wait=60000
    # \u914D\u7F6E\u95F4\u9694\u591A\u4E45\u624D\u8FDB\u884C\u4E00\u6B21\u68C0\u6D4B\uFF0C\u68C0\u6D4B\u9700\u8981\u5173\u95ED\u7684\u7A7A\u95F2\u8FDE\u63A5\uFF0C\u5355\u4F4D\u662F\u6BEB\u79D2
    spring.datasource.druid.time-between-eviction-runs-millis=60000
    # \u8FDE\u63A5\u4FDD\u6301\u7A7A\u95F2\u800C\u4E0D\u88AB\u9A71\u9010\u7684\u6700\u5C0F\u65F6\u95F4
    spring.datasource.druid.min-evictable-idle-time-millis=300000
    # \u7528\u6765\u68C0\u6D4B\u8FDE\u63A5\u662F\u5426\u6709\u6548\u7684sql\uFF0C\u8981\u6C42\u662F\u4E00\u4E2A\u67E5\u8BE2\u8BED\u53E5
    spring.datasource.druid.validation-query=SELECT 1 FROM DUAL
    # \u5EFA\u8BAE\u914D\u7F6E\u4E3Atrue\uFF0C\u4E0D\u5F71\u54CD\u6027\u80FD\uFF0C\u5E76\u4E14\u4FDD\u8BC1\u5B89\u5168\u6027\u3002\u7533\u8BF7\u8FDE\u63A5\u7684\u65F6\u5019\u68C0\u6D4B\uFF0C\u5982\u679C\u7A7A\u95F2\u65F6\u95F4\u5927\u4E8EtimeBetweenEvictionRunsMillis\uFF0C\u6267\u884CvalidationQuery\u68C0\u6D4B\u8FDE\u63A5\u662F\u5426\u6709\u6548\u3002
    spring.datasource.druid.test-while-idle=true
    # \u7533\u8BF7\u8FDE\u63A5\u65F6\u6267\u884CvalidationQuery\u68C0\u6D4B\u8FDE\u63A5\u662F\u5426\u6709\u6548\uFF0C\u505A\u4E86\u8FD9\u4E2A\u914D\u7F6E\u4F1A\u964D\u4F4E\u6027\u80FD\u3002
    spring.datasource.druid.test-on-borrow=false
    # \u5F52\u8FD8\u8FDE\u63A5\u65F6\u6267\u884CvalidationQuery\u68C0\u6D4B\u8FDE\u63A5\u662F\u5426\u6709\u6548\uFF0C\u505A\u4E86\u8FD9\u4E2A\u914D\u7F6E\u4F1A\u964D\u4F4E\u6027\u80FD\u3002
    spring.datasource.druid.test-on-return=false
    # \u662F\u5426\u7F13\u5B58preparedStatement\uFF0C\u4E5F\u5C31\u662FPSCache\u3002PSCache\u5BF9\u652F\u6301\u6E38\u6807\u7684\u6570\u636E\u5E93\u6027\u80FD\u63D0\u5347\u5DE8\u5927\uFF0C\u6BD4\u5982\u8BF4oracle\u3002\u5728mysql\u4E0B\u5EFA\u8BAE\u5173\u95ED\u3002
    spring.datasource.druid.pool-prepared-statements=true
    # \u8981\u542F\u7528PSCache\uFF0C\u5FC5\u987B\u914D\u7F6E\u5927\u4E8E0\uFF0C\u5F53\u5927\u4E8E0\u65F6\uFF0CpoolPreparedStatements\u81EA\u52A8\u89E6\u53D1\u4FEE\u6539\u4E3Atrue\u3002
    spring.datasource.druid.max-pool-prepared-statement-per-connection-size=50
    # \u914D\u7F6E\u76D1\u63A7\u7EDF\u8BA1\u62E6\u622A\u7684filters\uFF0C\u53BB\u6389\u540E\u76D1\u63A7\u754C\u9762sql\u65E0\u6CD5\u7EDF\u8BA1
    spring.datasource.druid.filters=stat,wall
    # \u901A\u8FC7connectProperties\u5C5E\u6027\u6765\u6253\u5F00mergeSql\u529F\u80FD\uFF1B\u6162SQL\u8BB0\u5F55
    spring.datasource.druid.connection-properties=druid.stat.mergeSql=true;druid.stat.slowSqlMillis=500
    # \u5408\u5E76\u591A\u4E2ADruidDataSource\u7684\u76D1\u63A7\u6570\u636E
    spring.datasource.druid.use-global-data-source-stat=true
    # druid\u8FDE\u63A5\u6C60\u76D1\u63A7
    spring.datasource.druid.stat-view-servlet.login-username=admin
    spring.datasource.druid.stat-view-servlet.login-password=123456
    # \u6392\u9664\u4E00\u4E9B\u9759\u6001\u8D44\u6E90\uFF0C\u4EE5\u63D0\u9AD8\u6548\u7387
    spring.datasource.druid.web-stat-filter.exclusions=*.js,*.gif,*.jpg,*.png,*.css,*.ico,/druid/*

1.  我在项目继承了mybatis-plus，利用mybatis plus 的**代码生成器**来生成代码 。[Mybatis-Plus官网地址][Mybatis-Plus].  
    ![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQ0OTIyMTEz_size_16_color_FFFFFF_t_70 6]（直接运行main方法）

#### 三、配置缓存 ####

1.  在resourses目录下创建一个cache的文件夹，导入配置文件![在这里插入图片描述][20200729103058612.png]

> cache.xml内容如下：

<?xml version="1.0" encoding="UTF-8"?>
    <ehcache xmlns:xsi = "http://www.w3.org/2001/XMLSchema-instance"
             xsi:noNamespaceSchemaLocation = "http://ehcache.org/ehcache.xsd"
             updateCheck = "false">
        
        <diskStore path = "java.io.tmpdir"/>
        
        <defaultCache
                name = "serviceCacheToken"
                eternal = "false"
                maxElementsInMemory = "10000"
                overflowToDisk = "true"
                diskPersistent = "false"
                timeToIdleSeconds = "7200"
                timeToLiveSeconds = "7200"
                diskExpiryThreadIntervalSeconds = "120"
                memoryStoreEvictionPolicy = "LRU"/>
    </ehcache>

1.  在config包下导入CacheConfig.java(key生成策略),内容如下

package com.mbyte.easy.config;
    
    import org.slf4j.Logger;
    import org.slf4j.LoggerFactory;
    import org.springframework.cache.interceptor.KeyGenerator;
    import org.springframework.context.annotation.Bean;
    import org.springframework.context.annotation.Configuration;
    
    /** * @ClassName: CacheConfig * @Description: 缓存配置 * @Author: zte * @Date: 2019-02-14 18:12 * @Version 1.0 **/
    @Configuration
    public class CacheConfig { 
        private final static Logger logger = LoggerFactory.getLogger(CacheConfig.class);
        /** * @Title: classKey * @Description: 以【类名】为缓存的key值 一般用于【selectALL】查询 * @Author: zte * @Date: 2019-03-01 15:42 * @return: org.springframework.cache.interceptor.KeyGenerator * @throws: */
        @Bean
        public KeyGenerator classKey() { 
            return (target, method, params) -> { 
                StringBuilder sb = new StringBuilder();
                sb.append(target.getClass().getName());
                logger.info("缓存classKey-key："+sb.toString());
                return sb.toString();
            };
    
        }
        /** * @Title: classMethodParamsKey * @Description: 以【类名+方法名+参数】为缓存的key值 * @Author: zte * @Date: 2019-03-01 15:43 * @return: org.springframework.cache.interceptor.KeyGenerator * @throws: */
        @Bean
        public KeyGenerator classMethodParamsKey() { 
            return (target, method, params) -> { 
                StringBuilder sb = new StringBuilder();
                sb.append(target.getClass().getName());
                sb.append(method.getName());
                for (Object obj : params) { 
                    sb.append(obj == null ? "" : obj.toString());
                }
                logger.info("缓存classMethodParamsKey-key："+sb.toString());
                return sb.toString();
            };
    
        }
    }

1.  主方法添加 开启缓存注解（**必须**）![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQ0OTIyMTEz_size_16_color_FFFFFF_t_70 7]

#### 四、实现登录接口 ####

代码如下

package com.mbyte.easy.rest.login;
    
    
    import com.baomidou.mybatisplus.core.conditions.query.LambdaQueryWrapper;
    import com.mbyte.easy.common.controller.BaseController;
    import com.mbyte.easy.user.entity.User;
    import com.mbyte.easy.user.service.IUserService;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.cache.Cache;
    import org.springframework.cache.CacheManager;
    import org.springframework.security.crypto.bcrypt.BCrypt;
    import org.springframework.web.bind.annotation.GetMapping;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.RequestParam;
    import org.springframework.web.bind.annotation.RestController;
    
    import javax.annotation.Resource;
    import java.util.HashMap;
    import java.util.Map;
    import java.util.UUID;
    
    /** * @author zte * @title: LoginController * @projectName easy * @description: 用户登录接口 * @date 2020/7/27 10:22 下午 */
    
    @RestController
    @RequestMapping("/rest/login")
    public class LoginController extends BaseController { 
        @Autowired
        private IUserService userService;
    
        @Resource
        private CacheManager cacheManager;
    
        /** * 登录验证 * @param username 用户名 * @param password 密码 * @return */
        @GetMapping
        public Map<String, Object> index(@RequestParam(value = "username") String username, @RequestParam(value = "password") String password){ 
            Map<String , Object> map = new HashMap<>();
            User user = userService.getOne(new LambdaQueryWrapper<User>().eq(User::getUserName , username));
            if(user != null && user.getPassword().equals(password)){ 
                Cache cache = cacheManager.getCache("serviceCacheToken");//serviceCacheToken，需要与配置文件xml里面的name保持一致
                String uuid = UUID.randomUUID().toString().replaceAll("-", "");
                //放入缓存
                cache.put(uuid, user);
    
                map.put("uuid",uuid);
                map.put("msg","success");
                return map;
            }
            map.put("msg","用户名或密码不正确");
            return map;
        }
    
        /** * 根据token加载用户信息 * @param token 令牌 * @return */
        @GetMapping("/loadUser")
        public Map<String, Object> loadUser(@RequestParam(value = "token") String token){ 
            Cache cache = cacheManager.getCache("serviceCacheToken");
            Map<String , Object> map = new HashMap<>();
            User user = cache.get(token, User.class);
            if(user != null){ 
                map.put("user",user);
                map.put("msg","success");
                return map;
            }
            map.put("msg","令牌已失效！");
            return map;
        }
    }

1.  登录接口（index），传入两个参数（用户名和密码），然后根据用户名到数据库去匹配，如果不存在，直接返回错误信息，如果存在继续匹配密码，如果密码也正确，创建一个缓存：

Cache cache = cacheManager.getCache("serviceCacheToken");
    //serviceCacheToken，需要与配置文件xml里面的name保持一致

生成一个UUID，作为key值，user对象作为value，存入缓存(类似于Map)：

String uuid = UUID.randomUUID().toString().replaceAll("-", "");
    //放入缓存
     cache.put(uuid, user);

然后将这个uuid返回回去，作为用户的身份标识，就是我们说的令牌。

1.  根据身份标识加载用户信息接口：传入用户身份标识，然后我们根据身份标识去匹配，匹配成功，将缓存的value，也就是我们存的user对象返回回去，如果匹配失败，则返回错误信息。

User user = cache.get(token, User.class);

#### 五、postman测试接口 ####

1.  首先我们现在数据库加载一条数据  
    ![在这里插入图片描述][20200729105226435.png]
2.  验证失败，提示信息  
    ![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQ0OTIyMTEz_size_16_color_FFFFFF_t_70 8]
3.  验证成功，返回用户身份标识，登录接口测试完毕。  
    ![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQ0OTIyMTEz_size_16_color_FFFFFF_t_70 9]
4.  然后我们根据返回的uuid测试加载信息接口![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQ0OTIyMTEz_size_16_color_FFFFFF_t_70 10]  
    我们可以看到，根据身份标识返回我们的用户信息
5.  到这里，缓存应用就讲解完毕了。有问题欢迎评论区留言。

[spring.io]: https://spring.io/
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQ0OTIyMTEz_size_16_color_FFFFFF_t_70]: /images/20230208/29a44622d2b545a38410070011471023.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQ0OTIyMTEz_size_16_color_FFFFFF_t_70 1]: /images/20230208/8aca26060f4747f69afc74d61c4e2062.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQ0OTIyMTEz_size_16_color_FFFFFF_t_70 2]: /images/20230208/3c33a61c3a194a5f99c490699c02342e.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQ0OTIyMTEz_size_16_color_FFFFFF_t_70 3]: /images/20230208/808f8d2265db4f08a57d4cab4f787c88.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQ0OTIyMTEz_size_16_color_FFFFFF_t_70 4]: /images/20230208/2218773d09db4fe5b06638e3a2b342ce.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQ0OTIyMTEz_size_16_color_FFFFFF_t_70 5]: /images/20230208/9ae89f6bc8ef4b228d1a4c21162e5e8c.png
[Mybatis-Plus]: https://mp.baomidou.com/
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQ0OTIyMTEz_size_16_color_FFFFFF_t_70 6]: /images/20230208/7c3ba18365fa4e1ab481c943afbf1bc8.png
[20200729103058612.png]: /images/20230208/bbe3aa599d884273b69394cdbcde3257.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQ0OTIyMTEz_size_16_color_FFFFFF_t_70 7]: /images/20230208/c0133ea5a3cf4a0187f5aa2d3a855fac.png
[20200729105226435.png]: /images/20230208/d186a3243e6740d3966ad3370866833c.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQ0OTIyMTEz_size_16_color_FFFFFF_t_70 8]: /images/20230208/991fd74aa5ec4620a53ea60191931043.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQ0OTIyMTEz_size_16_color_FFFFFF_t_70 9]: /images/20230208/9b70165c93d8448aae757ae4b5bd26fd.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQ0OTIyMTEz_size_16_color_FFFFFF_t_70 10]: /images/20230208/ffc2d05261324d63a4e724f90425a315.png