SpringBoot中的@Configuration注解详解

package com.hadoopx.mallx.data.config.redis;
import org.apache.commons.pool2.impl.GenericObjectPoolConfig;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.data.redis.connection.RedisPassword;
import org.springframework.data.redis.connection.RedisStandaloneConfiguration;
import org.springframework.data.redis.connection.lettuce.LettuceClientConfiguration;
import org.springframework.data.redis.connection.lettuce.LettuceConnectionFactory;
import org.springframework.data.redis.connection.lettuce.LettucePoolingClientConfiguration;
import org.springframework.data.redis.core.StringRedisTemplate;
import java.time.Duration;
@Configuration
public class RedisAutoConfig {
    @Bean
    public LettuceConnectionFactory defaultLettuceConnectionFactory(RedisStandaloneConfiguration defaultRedisConfig, GenericObjectPoolConfig defaultPoolConfig) {
        LettuceClientConfiguration clientConfig =
                LettucePoolingClientConfiguration.builder().commandTimeout(Duration.ofMillis(5000))
                        .poolConfig(defaultPoolConfig).build();
        return new LettuceConnectionFactory(defaultRedisConfig, clientConfig);
    }
    @Bean
    public StringRedisTemplate stringRedisTemplate(LettuceConnectionFactory defaultLettuceConnectionFactory) {
        StringRedisTemplate stringRedisTemplate = new StringRedisTemplate();
        stringRedisTemplate.setConnectionFactory(defaultLettuceConnectionFactory);
        return stringRedisTemplate;
    }
    @Configuration
    public static class DefaultRedisConfig {
        /**
         * 获取配置文件中spring.redis.host的值, 如果没有则使用默认值: 127.0.0.1
         * 使用如下:
         * @Value("${YML-KEY:DEFAULT-VALUE}")
         */
        @Value("${spring.redis.host:127.0.0.1}")
        private String host;
        @Value("${spring.redis.port:6379}")
        private Integer port;
        @Value("${spring.redis.password:}")
        private String password;
        @Value("${spring.redis.database:0}")
        private Integer database;
        @Value("${spring.redis.lettuce.pool.max-active:8}")
        private Integer maxActive;
        @Value("${spring.redis.lettuce.pool.max-idle:8}")
        private Integer maxIdle;
        @Value("${spring.redis.lettuce.pool.max-wait:-1}")
        private Long maxWait;
        @Value("${spring.redis.lettuce.pool.min-idle:0}")
        private Integer minIdle;
        @Bean
        public GenericObjectPoolConfig defaultPoolConfig() {
            GenericObjectPoolConfig config = new GenericObjectPoolConfig();
            config.setMaxTotal(maxActive);
            config.setMaxIdle(maxIdle);
            config.setMinIdle(minIdle);
            config.setMaxWaitMillis(maxWait);
            return config;
        }
        @Bean
        public RedisStandaloneConfiguration defaultRedisConfig() {
            RedisStandaloneConfiguration config = new RedisStandaloneConfiguration();
            config.setHostName(host);
            config.setPassword(RedisPassword.of(password));
            config.setPort(port);
            config.setDatabase(database);
            return config;
        }
    }
}

@Configuration(proxyBeanMethods = true) //告诉springboot这是一个配置类 == 配置文件
public class Myconfig {
    @Bean//给容器中添加组件，以方法名作为组件的id。
    // 返回类型为组件类型，返回的值，就是组件在容器中的实例
    public User user01(){
        User wangcai = new User("wangcai",23);
        //user组件依赖了pet组件
        wangcai.setPet(pet01());
        return wangcai;
    }
    @Bean
    public Pet pet01(){
        return new Pet("旺财");
    }
}

@Configuration
public class MyConfig {
    @Bean("user")
    @Scope(SCOPE_PROTOTYPE)         //多例
    public User getUser(){
        System.out.println("User对象进行创建!");
        return new User("用户", 22, getDog());
    }
    @Bean("dog")
    @Scope(SCOPE_SINGLETON)         //单例
    public Dog getDog(){
        System.out.println("Dog对象进行创建!");
        return new Dog("金毛", 3);
    }
}