springboot学习笔记-4 整合Druid数据源和使用@Cache简化redis配置

时间:2023-03-09 03:21:25
springboot学习笔记-4 整合Druid数据源和使用@Cache简化redis配置

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.

  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.

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

  实体类的主要属性如下:

springboot学习笔记-4 整合Druid数据源和使用@Cache简化redis配置

@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).而@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