1000. JAVA基础

1. 泛型

1.1 泛型和Object的区别

泛型和Object的区别 什么时候用泛型 什么时候使用Object

1100. Spring

1. 常用注解

1.1 @ControllerAdvice注解

spring的@ControllerAdvice注解

1.2 缓存@Cacheable

@Cacheable使用详解
@Cacheable 注解在方法上，表示该方法的返回结果是可以缓存的。也就是说，该方法的返回结果会放在缓存中，以便于以后使用相同的参数调用该方法时，会返回缓存中的值，而不会实际执行该方法。

依赖

    <dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-data-redis</artifactId></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-cache</artifactId></dependency>

配置类

package com.imooc.mall.config;import java.time.Duration;import org.springframework.cache.annotation.EnableCaching;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.data.redis.cache.RedisCacheConfiguration;
import org.springframework.data.redis.cache.RedisCacheManager;
import org.springframework.data.redis.cache.RedisCacheWriter;
import org.springframework.data.redis.connection.RedisConnectionFactory;/*** 描述：     缓存的配置类*/
@Configuration
@EnableCaching
public class CachingConfig {@Beanpublic RedisCacheManager redisCacheManager(RedisConnectionFactory connectionFactory) {RedisCacheWriter redisCacheWriter = RedisCacheWriter.lockingRedisCacheWriter(connectionFactory);RedisCacheConfiguration cacheConfiguration = RedisCacheConfiguration.defaultCacheConfig();//超时时间30scacheConfiguration = cacheConfiguration.entryTtl(Duration.ofSeconds(30));RedisCacheManager redisCacheManager = new RedisCacheManager(redisCacheWriter, cacheConfiguration);return redisCacheManager;}
}

启动类需要@EnableCaching描述

package com.imooc.mall;import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cache.annotation.EnableCaching;
import springfox.documentation.swagger2.annotations.EnableSwagger2;@SpringBootApplication
@MapperScan(basePackages = "com.imooc.mall.model.dao")
@EnableSwagger2
@EnableCaching
public class MallApplication {public static void main(String[] args) {SpringApplication.run(MallApplication.class, args);}}

应用

	import org.springframework.cache.annotation.Cacheable;@Override@Cacheable(value = "listCategoryForCustomer")public List<CategoryVO> listCategoryForCustomer() {ArrayList<CategoryVO> categoryVOList = new ArrayList<>();recursivelyFindCategories(categoryVOList, 0);return categoryVOList;}

2. 常用方法

2.1 BeanUtils.copyProperties的用法

BeanUtils.copyProperties的用法(超详细，建议收藏)

如果有两个具有很多相同属性名的JavaBean对象a和b，想把a中的属性赋值到b

3. 常用功能组件

3.1 过滤器Filter

Filter（过滤器）简介

JavaWeb过滤器(Filter)详解

2000. Linux应用