SpringBoot集成Redis后配置如何查找

当使用SpringBoot自动化集成各个组件时，各个组件的配置应该如何方便查找呢，下面以redis为例说明：

首先到spring-boot-autoconfigure-2.1.1.RELEASE.jar的META-INF下找到spring.factories文件，文件内容如下，是SpringBoot自动集成各个组件的配置类：

org.springframework.boot.autoconfigure.data.mongo.MongoDataAutoConfiguration,\
org.springframework.boot.autoconfigure.data.mongo.MongoReactiveDataAutoConfiguration,\
org.springframework.boot.autoconfigure.data.mongo.MongoReactiveRepositoriesAutoConfiguration,\
org.springframework.boot.autoconfigure.data.mongo.MongoRepositoriesAutoConfiguration,\
org.springframework.boot.autoconfigure.data.neo4j.Neo4jDataAutoConfiguration,\
org.springframework.boot.autoconfigure.data.neo4j.Neo4jRepositoriesAutoConfiguration,\
org.springframework.boot.autoconfigure.data.solr.SolrRepositoriesAutoConfiguration,\
org.springframework.boot.autoconfigure.data.redis.RedisAutoConfiguration,\
org.springframework.boot.autoconfigure.data.redis.RedisReactiveAutoConfiguration,\
org.springframework.boot.autoconfigure.data.redis.RedisRepositoriesAutoConfiguration,\
org.springframework.boot.autoconfigure.data.rest.RepositoryRestMvcAutoConfiguration,\
org.springframework.boot.autoconfigure.data.web.SpringDataWebAutoConfiguration,\
org.springframework.boot.autoconfigure.elasticsearch.jest.JestAutoConfiguration,\
org.springframework.boot.autoconfigure.elasticsearch.rest.RestClientAutoConfiguration,\

比如以RedisAutoConfiguration为例：

package org.springframework.boot.autoconfigure.data.redis;

import java.net.UnknownHostException;

import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
import org.springframework.boot.context.properties.EnableConfigurationProperties;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Import;
import org.springframework.data.redis.connection.RedisConnectionFactory;
import org.springframework.data.redis.core.RedisOperations;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.data.redis.core.StringRedisTemplate;

@Configuration
@ConditionalOnClass(RedisOperations.class)
@EnableConfigurationProperties(RedisProperties.class)
@Import({ LettuceConnectionConfiguration.class, JedisConnectionConfiguration.class })
public class RedisAutoConfiguration {

    @Bean
    @ConditionalOnMissingBean(name = "redisTemplate")
    public RedisTemplate<Object, Object> redisTemplate(
            RedisConnectionFactory redisConnectionFactory) throws UnknownHostException {
        RedisTemplate<Object, Object> template = new RedisTemplate<>();
        template.setConnectionFactory(redisConnectionFactory);
        return template;
    }

    @Bean
    @ConditionalOnMissingBean
    public StringRedisTemplate stringRedisTemplate(
            RedisConnectionFactory redisConnectionFactory) throws UnknownHostException {
        StringRedisTemplate template = new StringRedisTemplate();
        template.setConnectionFactory(redisConnectionFactory);
        return template;
    }

}

注意其中的@EnableConfigurationProperties(RedisProperties.class)：

package org.springframework.boot.autoconfigure.data.redis;

import java.time.Duration;
import java.util.List;

import org.springframework.boot.context.properties.ConfigurationProperties;


@ConfigurationProperties(prefix = "spring.redis")
public class RedisProperties {

    /**
     * Database index used by the connection factory.
     */
    private int database = 0;

    /**
     * Connection URL. Overrides host, port, and password. User is ignored. Example:
     * redis://user:password@example.com:6379
     */
    private String url;

    /**
     * Redis server host.
     */
    private String host = "localhost";

    /**
     * Login password of the redis server.
     */
    private String password;

    /**
     * Redis server port.
     */
    private int port = 6379;

    /**
     * Whether to enable SSL support.
     */
    private boolean ssl;

    /**
     * Connection timeout.
     */
    private Duration timeout;

    private Sentinel sentinel;

    private Cluster cluster;

    private final Jedis jedis = new Jedis();

    private final Lettuce lettuce = new Lettuce();

    

}

上边的RedisProperties就是集成redis之后的配置类。@ConfigurationProperties(prefix = "spring.redis")表示在properties或yml中配置redis的前缀，类中属性就是具体各个配置项，具体配置文件如下：

# Spring配置
spring:
  redis:
    # 地址
    host: localhost
    # 端口，默认为6379
    port: 6379
    # 密码
    password: 

可以看出配置文件与RedisProperties类的属性一一对应。

集成的其他组件的配置也是采用相同的实现思路，可以按规则找到配置文件，以明确有哪些配置项，以及配置项的默认值。

比如：ServerProperties（servlet的配置）、DataSourceProperties（数据源的配置）。