深入学习SpringBoot(四):整合Druid数据源和@Cache简化redis配置

亦凉 2022-01-20 01:25 129阅读 0赞

BigDataKer 2019-06-10 08:35:00

**一.整合Druid数据源**

Druid是一个关系型数据库连接池,是阿里巴巴的一个开源项目,Druid在监控,可扩展性,稳定性和性能方面具有比较明显的优势.通过Druid提供的监控功能,可以实时观察数据库连接池和SQL查询的工作情况.使用Druid在一定程度上可以提高数据库的访问技能.

![深入学习SpringBoot(四):整合Druid数据源和@Cache简化redis配置][SpringBoot_Druid_Cache_redis]

**1.1 在pom.xml中添加依赖**

<dependency>
     <groupId>com.alibaba</groupId>
     <artifactId>druid</artifactId>
     <version>1.0.18</version>
    </dependency>

**1.2 Druid数据源配置**

在application.properties中,去书写Druid数据源的配置信息.

##Druid##
    spring.datasource.type=com.alibaba.druid.pool.DruidDataSource
    spring.datasource.driver-class-name=com.mysql.jdbc.Driver
    spring.datasource.url=jdbc:mysql://localhost:3306/test?characterEncoding=UTF-8
    spring.datasource.username=root
    spring.datasource.password=root
    spring.datasource.initialSize=5
    spring.datasource.minIdle=5
    spring.datasource.maxActive=20
    spring.datasource.maxWait=60000
    spring.datasource.timeBetweenEvictionRunsMillis=60000
    spring.datasource.minEvictableIdleTimeMillis=300000
    spring.datasource.validationQuery=SELECT 1 FROM DUAL
    spring.datasource.testWhileIdle=true
    spring.datasource.testOnBorrow=false
    spring.datasource.testOnReturn=false
    spring.datasource.poolPreparedStatements=true
    spring.datasource.maxPoolPreparedStatementPerConnectionSize=20
    spring.datasource.filters=stat,wall,log4j
    spring.datasource.connectionProperties=druid.stat.mergeSql=true;druid.stat.slowSqlMillis=5000
    spring.datasource.useGlobalDataSourceStat=true

**1.3 建立DruidConfiguration配置类,配置过滤信息**

@Configuration
    public class DruidConfiguration {
    
    @Bean
    public ServletRegistrationBean statViewServle() {
        ServletRegistrationBean servletRegistrationBean = new ServletRegistrationBean(new StatViewServlet(), "/druid/*");
        //白名单：
        servletRegistrationBean.addInitParameter("allow", "192.168.1.218,127.0.0.1");
        //IP黑名单 (存在共同时，deny优先于allow) : 如果满足deny的即提示:Sorry, you are not permitted to view this page.
        servletRegistrationBean.addInitParameter("deny", "192.168.1.100");
        //登录查看信息的账号密码.
        servletRegistrationBean.addInitParameter("loginUsername", "druid");
        servletRegistrationBean.addInitParameter("loginPassword", "12345678");
        //是否能够重置数据.
        servletRegistrationBean.addInitParameter("resetEnable", "false");
        return servletRegistrationBean;
    }
    
    @Bean
    public FilterRegistrationBean statFilter() {
        FilterRegistrationBean filterRegistrationBean = new FilterRegistrationBean(new WebStatFilter());
        //添加过滤规则.
        filterRegistrationBean.addUrlPatterns("/*");
        //添加不需要忽略的格式信息.
        filterRegistrationBean.addInitParameter("exclusions", "*.js,*.gif,*.jpg,*.png,*.css,*.ico,/druid/*");
        return filterRegistrationBean;
    }
    }

**1.4 配置数据源的信息**

告诉springboot采用Druid数据源:

@Bean(name = "dataSource")
     @Primary
     @ConfigurationProperties(prefix = "spring.datasource")
     public DataSource dataSource(){
     return DataSourceBuilder.create().type(com.alibaba.druid.pool.DruidDataSource.class).build();
     }

接下来就可以通过localhost:8080/druid/index.html去打开控制台,观察过滤信息了!

**二.使用@Cache简化redis配置**

在实体类比较简单的时候(例如:没有一对多,多对多这类复杂的关系,不是List,Map这类数据类型,只是一个Pojo类),可以使用@Cache去替代书写BeanRedis注入RedisTemplate的方式去访问Redis数据库.

![深入学习SpringBoot(四):整合Druid数据源和@Cache简化redis配置][SpringBoot_Druid_Cache_redis 1]

**2.1 建立RoleService.采用@Cacheable和@CachePut去访问Redis**

实体类的主要属性如下：

![深入学习SpringBoot(四):整合Druid数据源和@Cache简化redis配置][SpringBoot_Druid_Cache_redis 2]

@Service
    public class RoleService {
    
    @Autowired
    private RoleRepository roleRepository;
    
    @Autowired
    private RoleRedis roleRedis;
    
    @Cacheable(value = "mysql:findById:role", keyGenerator = "simpleKey")
    public Role findById(Long id) {
        System.out.println("从数据库中查询");
        return roleRepository.findOne(id);
    }
    
    @CachePut(value = "mysql:findById:role", keyGenerator = "objectId")
    public Role create(Role role) {
        System.out.println("************在数据库中创建************");
        return roleRepository.save(role);
    }
    
    //简单的操作使用注解的形式
    @CachePut(value = "mysql:findById:role", keyGenerator = "objectId")
    public Role update(Role role) {
        System.out.println("************在数据库中更新************");
        return roleRepository.save(role);
    }
    
    @CacheEvict(value = "mysql:findById:role", keyGenerator = "simpleKey")
    public void delete(Long id) {
        System.out.println("************在数据库中销毁************");
        roleRepository.delete(id);
    }
    
    public List<Role> findAll() {
        List<Role> roleList = roleRedis.getList("mysql:findAll:role");
        if (roleList == null) {
            roleList = roleRepository.findAll();
            if (roleList != null)
                roleRedis.add("mysql:findAll:role", 5L, roleList);
        }
        return roleList;
    }
    
    //复杂的依然使用RedisTemplate的形式
    public Page<Role> findPage(RoleQo roleQo) {
        Pageable pageable = new PageRequest(roleQo.getPage(), roleQo.getSize(), new Sort(Sort.Direction.ASC, "id"));
        PredicateBuilder pb = new PredicateBuilder();
        if (!StringUtils.isEmpty(roleQo.getName())) {
            pb.add("name", "%" + roleQo.getName() + "%", LinkEnum.LIKE);
        }
        Page<Role> pages = roleRepository.findAll(pb.build(), Operator.AND, pageable);
        return pages;
    } 
    }

注意：

@Cacheable放置于方法上,当调用这个方法时,程序会先根据key(value加上KeyGenerator生成的key)去寻找有没有对应的对象结果,如果有的话,直接返回,没有才执行方法(从数据库找)。

@CachePut则会更新Redis缓存,同时执行对应的方法。

@CacheEvict会删除Redis缓存对应的对象.

**2.2 建立Redis配置类,需要去配置Redis的注解**

@ConfigurationProperties("application.properties")
    @Configuration
    @EnableCaching
    public class RedisConfig extends CachingConfigurerSupport {
    
     @Value("${spring.redis.hostName}")
     private String hostName;
    
     @Value("${spring.redis.port}")
     private Integer port;
     
    @Bean
    public RedisConnectionFactory redisConnectionFactory() {
        JedisConnectionFactory cf = new JedisConnectionFactory();
        cf.setHostName(hostName);
        cf.setPort(port);
        cf.afterPropertiesSet();
        return cf;
    }
    
    //配置key的生成
    @Bean
    public KeyGenerator simpleKey() {
        return new KeyGenerator() {
            @Override
            public Object generate(Object target, Method method, Object... params) {
                StringBuilder sb = new StringBuilder();
                sb.append(target.getClass().getName() + ":");
                for (Object obj : params) {
                    sb.append(obj.toString());
                }
                return sb.toString();
            }
        };
    }

//配置key的生成
    @Bean
    public KeyGenerator objectId() {
        return new KeyGenerator() {
            @Override
            public Object generate(Object target, Method method, Object... params) {
                StringBuilder sb = new StringBuilder();
                sb.append(target.getClass().getName() + ":");
                try {
                    sb.append(params[0].getClass().getMethod("getId", null).invoke(params[0], null).toString());
                } catch (NoSuchMethodException no) {
                    no.printStackTrace();
                } catch (IllegalAccessException il) {
                    il.printStackTrace();
                } catch (InvocationTargetException iv) {
                    iv.printStackTrace();
                }
                return sb.toString();
            }
        };
    }
    
    //配置注解
    @Bean
    public CacheManager cacheManager(@SuppressWarnings("rawtypes") RedisTemplate redisTemplate) {
        RedisCacheManager manager = new RedisCacheManager(redisTemplate);
        manager.setDefaultExpiration(43200);//12小时
        return manager;
    }

//对于复杂的属性仍然使用RedisTemplate
    @Bean
    public RedisTemplate<String, String> redisTemplate(
            RedisConnectionFactory factory) {
        StringRedisTemplate template = new StringRedisTemplate(factory);
        Jackson2JsonRedisSerializer jackson2JsonRedisSerializer = new Jackson2JsonRedisSerializer(Object.class);
        ObjectMapper om = new ObjectMapper();
        om.setVisibility(PropertyAccessor.ALL, JsonAutoDetect.Visibility.ANY);
        om.enableDefaultTyping(ObjectMapper.DefaultTyping.NON_FINAL);
        jackson2JsonRedisSerializer.setObjectMapper(om);
        template.setValueSerializer(jackson2JsonRedisSerializer);
        template.afterPropertiesSet();
        return template;
    }
    }

**2.3 测试**

# 上一篇:[深入学习SpringBoot(三):springboot整合redis&mongodb][SpringBoot_springboot_redis_mongodb] #

本文转自博客园：hlhdidi的博客,版权归原作者所有

[SpringBoot_Druid_Cache_redis]: http://p1.pstatp.com/large/pgc-image/5cc9f015a43441e4b24732738e2b8557
[SpringBoot_Druid_Cache_redis 1]: /images/20220120/02da394e8ee94cf1b2389c2917bc9be4.png
[SpringBoot_Druid_Cache_redis 2]: http://p1.pstatp.com/large/pgc-image/9e385b4e0cd04d15b9d0eb6f7909dec2
[SpringBoot_springboot_redis_mongodb]: https://www.toutiao.com/i6700347655731544579/?group_id=6700347655731544579