一、前言

  • Springboot源码解析是一件大工程，逐行逐句的去研究代码，会很枯燥，也不容易坚持下去。
  • 我们不追求大而全，而是试着每次去研究一个小知识点，最终聚沙成塔，这就是我们的springboot源码管中窥豹系列。

二、何为自动装配？

  • 我们想用redis，直接引入spring-boot-starter-data-redis的依赖，配置加上就能用。
  • 我们想用mongodb, 直接引入mongodb的依赖
  • 我们想用缓存，直接引入cache的依赖
  • 我们在：springboot源码解析-管中窥豹系列之web服务器（七） 里面想更换不同的web服务器，更换不同的依赖，那里也是用到自动装配

三、源码分析

我们从main方法所在类开始看：

import org.springframework.boot.SpringApplication;

import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication

public class MyprojectApplication {

    public static void main(String[] args) {

        SpringApplication.run(MyprojectApplication.class, args);

    }

}

这次不进main方法，我们看注解：@SpringBootApplication

@Target(ElementType.TYPE)

@Retention(RetentionPolicy.RUNTIME)

@Documented

@Inherited

@SpringBootConfiguration

@EnableAutoConfiguration

@ComponentScan(excludeFilters = { @Filter(type = FilterType.CUSTOM, classes = TypeExcludeFilter.class),

		@Filter(type = FilterType.CUSTOM, classes = AutoConfigurationExcludeFilter.class) })

public @interface SpringBootApplication {

    ...

}
  • 我们看这个注解：@EnableAutoConfiguration
  • 注意这个注解是在：spring-boot-autoconifgure依赖包里面
@Target(ElementType.TYPE)

@Retention(RetentionPolicy.RUNTIME)

@Documented

@Inherited

@AutoConfigurationPackage

@Import(AutoConfigurationImportSelector.class)

public @interface EnableAutoConfiguration {

	String ENABLED_OVERRIDE_PROPERTY = "spring.boot.enableautoconfiguration";

	Class<?>[] exclude() default {};

	String[] excludeName() default {};

}
  • spring.boot.enableautoconfiguration：自动装配的开关，默认开
  • 我们看这个：@Import(AutoConfigurationImportSelector.class)
  • springboot会加载@Import 和 继承ImportSelector的类 到bean集合里面
public class AutoConfigurationImportSelector implements DeferredImportSelector, BeanClassLoaderAware,

		ResourceLoaderAware, BeanFactoryAware, EnvironmentAware, Ordered {

    ...

}
  • 继承的各种Aware，我们之前说过：springboot源码解析-管中窥豹系列之aware（六）
  • Ordered：我们在之前排序那一节也说过：springboot源码解析-管中窥豹系列之排序（五）
  • ImportSelector是把继承的selectImports方法的返回数组转换成加载的bean
public class AutoConfigurationImportSelector implements DeferredImportSelector, BeanClassLoaderAware,

		ResourceLoaderAware, BeanFactoryAware, EnvironmentAware, Ordered {

    ....

	private static final String[] NO_IMPORTS = {};

	@Override

	public String[] selectImports(AnnotationMetadata annotationMetadata) {

		if (!isEnabled(annotationMetadata)) {

			return NO_IMPORTS;

		}

		AutoConfigurationEntry autoConfigurationEntry = getAutoConfigurationEntry(annotationMetadata);

		return StringUtils.toStringArray(autoConfigurationEntry.getConfigurations());

	}

	protected boolean isEnabled(AnnotationMetadata metadata) {

		if (getClass() == AutoConfigurationImportSelector.class) {

			return getEnvironment().getProperty(EnableAutoConfiguration.ENABLED_OVERRIDE_PROPERTY, Boolean.class, true);

		}

		return true;

	}

    ....

}
  • 先判断开关，没打开就返回空数组
  • getAutoConfigurationEntry() 拿到要加载成bean的对象
  • 转换成数组返回
  • 我们看看这个方法：getAutoConfigurationEntry()
protected AutoConfigurationEntry getAutoConfigurationEntry(AnnotationMetadata annotationMetadata) {

    if (!isEnabled(annotationMetadata)) {

        return EMPTY_ENTRY;

    }

    AnnotationAttributes attributes = getAttributes(annotationMetadata);

    List<String> configurations = getCandidateConfigurations(annotationMetadata, attributes);

    configurations = removeDuplicates(configurations);

    Set<String> exclusions = getExclusions(annotationMetadata, attributes);

    checkExcludedClasses(configurations, exclusions);

    configurations.removeAll(exclusions);

    configurations = getConfigurationClassFilter().filter(configurations);

    fireAutoConfigurationImportEvents(configurations, exclusions);

    return new AutoConfigurationEntry(configurations, exclusions);

}
  • 其它行都是加工数据的，或者exlusions(排除)，filter(过滤)
  • 最重要的是：List configurations = getCandidateConfigurations(annotationMetadata, attributes);
  • 我们看这个方法：getCandidateConfigurations
protected List<String> getCandidateConfigurations(AnnotationMetadata metadata, AnnotationAttributes attributes) {

    List<String> configurations = SpringFactoriesLoader.loadFactoryNames(getSpringFactoriesLoaderFactoryClass(),

            getBeanClassLoader());

    Assert.notEmpty(configurations, "No auto configuration classes found in META-INF/spring.factories. If you "

            + "are using a custom packaging, make sure that file is correct.");

    return configurations;

}

protected Class<?> getSpringFactoriesLoaderFactoryClass() {

    return EnableAutoConfiguration.class;

}
  • SpringFactoriesLoader.loadFactoryNames, 我们之前说过，是从spring.factories里面加载对应的class
  • 这次要加载的class: EnableAutoConfiguration
  • 我们到spring.factories里面找找
# Auto Configure

org.springframework.boot.autoconfigure.EnableAutoConfiguration=\

org.springframework.boot.autoconfigure.admin.SpringApplicationAdminJmxAutoConfiguration,\

org.springframework.boot.autoconfigure.aop.AopAutoConfiguration,\

org.springframework.boot.autoconfigure.amqp.RabbitAutoConfiguration,\

org.springframework.boot.autoconfigure.batch.BatchAutoConfiguration,\

org.springframework.boot.autoconfigure.cache.CacheAutoConfiguration,\

org.springframework.boot.autoconfigure.cassandra.CassandraAutoConfiguration,\

org.springframework.boot.autoconfigure.context.ConfigurationPropertiesAutoConfiguration,\

org.springframework.boot.autoconfigure.context.LifecycleAutoConfiguration,\

org.springframework.boot.autoconfigure.context.MessageSourceAutoConfiguration,\

org.springframework.boot.autoconfigure.context.PropertyPlaceholderAutoConfiguration,\

org.springframework.boot.autoconfigure.couchbase.CouchbaseAutoConfiguration,\

org.springframework.boot.autoconfigure.dao.PersistenceExceptionTranslationAutoConfiguration,\

org.springframework.boot.autoconfigure.data.cassandra.CassandraDataAutoConfiguration,\

org.springframework.boot.autoconfigure.data.cassandra.CassandraReactiveDataAutoConfiguration,\

org.springframework.boot.autoconfigure.data.cassandra.CassandraReactiveRepositoriesAutoConfiguration,\

org.springframework.boot.autoconfigure.data.cassandra.CassandraRepositoriesAutoConfiguration,\

org.springframework.boot.autoconfigure.data.couchbase.CouchbaseDataAutoConfiguration,\

org.springframework.boot.autoconfigure.data.couchbase.CouchbaseReactiveDataAutoConfiguration,\

org.springframework.boot.autoconfigure.data.couchbase.CouchbaseReactiveRepositoriesAutoConfiguration,\

org.springframework.boot.autoconfigure.data.couchbase.CouchbaseRepositoriesAutoConfiguration,\

org.springframework.boot.autoconfigure.data.elasticsearch.ElasticsearchDataAutoConfiguration,\

org.springframework.boot.autoconfigure.data.elasticsearch.ElasticsearchRepositoriesAutoConfiguration,\

org.springframework.boot.autoconfigure.data.elasticsearch.ReactiveElasticsearchRepositoriesAutoConfiguration,\

org.springframework.boot.autoconfigure.data.elasticsearch.ReactiveElasticsearchRestClientAutoConfiguration,\

org.springframework.boot.autoconfigure.data.jdbc.JdbcRepositoriesAutoConfiguration,\

org.springframework.boot.autoconfigure.data.jpa.JpaRepositoriesAutoConfiguration,\

org.springframework.boot.autoconfigure.data.ldap.LdapRepositoriesAutoConfiguration,\

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.r2dbc.R2dbcDataAutoConfiguration,\

org.springframework.boot.autoconfigure.data.r2dbc.R2dbcRepositoriesAutoConfiguration,\

org.springframework.boot.autoconfigure.data.r2dbc.R2dbcTransactionManagerAutoConfiguration,\

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.ElasticsearchRestClientAutoConfiguration,\

org.springframework.boot.autoconfigure.flyway.FlywayAutoConfiguration,\

org.springframework.boot.autoconfigure.freemarker.FreeMarkerAutoConfiguration,\

org.springframework.boot.autoconfigure.groovy.template.GroovyTemplateAutoConfiguration,\

org.springframework.boot.autoconfigure.gson.GsonAutoConfiguration,\

org.springframework.boot.autoconfigure.h2.H2ConsoleAutoConfiguration,\

org.springframework.boot.autoconfigure.hateoas.HypermediaAutoConfiguration,\

org.springframework.boot.autoconfigure.hazelcast.HazelcastAutoConfiguration,\

org.springframework.boot.autoconfigure.hazelcast.HazelcastJpaDependencyAutoConfiguration,\

org.springframework.boot.autoconfigure.http.HttpMessageConvertersAutoConfiguration,\

org.springframework.boot.autoconfigure.http.codec.CodecsAutoConfiguration,\

org.springframework.boot.autoconfigure.influx.InfluxDbAutoConfiguration,\

org.springframework.boot.autoconfigure.info.ProjectInfoAutoConfiguration,\

org.springframework.boot.autoconfigure.integration.IntegrationAutoConfiguration,\

org.springframework.boot.autoconfigure.jackson.JacksonAutoConfiguration,\

org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration,\

org.springframework.boot.autoconfigure.jdbc.JdbcTemplateAutoConfiguration,\

org.springframework.boot.autoconfigure.jdbc.JndiDataSourceAutoConfiguration,\

org.springframework.boot.autoconfigure.jdbc.XADataSourceAutoConfiguration,\

org.springframework.boot.autoconfigure.jdbc.DataSourceTransactionManagerAutoConfiguration,\

org.springframework.boot.autoconfigure.jms.JmsAutoConfiguration,\

org.springframework.boot.autoconfigure.jmx.JmxAutoConfiguration,\

org.springframework.boot.autoconfigure.jms.JndiConnectionFactoryAutoConfiguration,\

org.springframework.boot.autoconfigure.jms.activemq.ActiveMQAutoConfiguration,\

org.springframework.boot.autoconfigure.jms.artemis.ArtemisAutoConfiguration,\

org.springframework.boot.autoconfigure.jersey.JerseyAutoConfiguration,\

org.springframework.boot.autoconfigure.jooq.JooqAutoConfiguration,\

org.springframework.boot.autoconfigure.jsonb.JsonbAutoConfiguration,\

org.springframework.boot.autoconfigure.kafka.KafkaAutoConfiguration,\

org.springframework.boot.autoconfigure.availability.ApplicationAvailabilityAutoConfiguration,\

org.springframework.boot.autoconfigure.ldap.embedded.EmbeddedLdapAutoConfiguration,\

org.springframework.boot.autoconfigure.ldap.LdapAutoConfiguration,\

org.springframework.boot.autoconfigure.liquibase.LiquibaseAutoConfiguration,\

org.springframework.boot.autoconfigure.mail.MailSenderAutoConfiguration,\

org.springframework.boot.autoconfigure.mail.MailSenderValidatorAutoConfiguration,\

org.springframework.boot.autoconfigure.mongo.embedded.EmbeddedMongoAutoConfiguration,\

org.springframework.boot.autoconfigure.mongo.MongoAutoConfiguration,\

org.springframework.boot.autoconfigure.mongo.MongoReactiveAutoConfiguration,\

org.springframework.boot.autoconfigure.mustache.MustacheAutoConfiguration,\

org.springframework.boot.autoconfigure.orm.jpa.HibernateJpaAutoConfiguration,\

org.springframework.boot.autoconfigure.quartz.QuartzAutoConfiguration,\

org.springframework.boot.autoconfigure.r2dbc.R2dbcAutoConfiguration,\

org.springframework.boot.autoconfigure.rsocket.RSocketMessagingAutoConfiguration,\

org.springframework.boot.autoconfigure.rsocket.RSocketRequesterAutoConfiguration,\

org.springframework.boot.autoconfigure.rsocket.RSocketServerAutoConfiguration,\

org.springframework.boot.autoconfigure.rsocket.RSocketStrategiesAutoConfiguration,\

org.springframework.boot.autoconfigure.security.servlet.SecurityAutoConfiguration,\

org.springframework.boot.autoconfigure.security.servlet.UserDetailsServiceAutoConfiguration,\

org.springframework.boot.autoconfigure.security.servlet.SecurityFilterAutoConfiguration,\

org.springframework.boot.autoconfigure.security.reactive.ReactiveSecurityAutoConfiguration,\

org.springframework.boot.autoconfigure.security.reactive.ReactiveUserDetailsServiceAutoConfiguration,\

org.springframework.boot.autoconfigure.security.rsocket.RSocketSecurityAutoConfiguration,\

org.springframework.boot.autoconfigure.security.saml2.Saml2RelyingPartyAutoConfiguration,\

org.springframework.boot.autoconfigure.sendgrid.SendGridAutoConfiguration,\

org.springframework.boot.autoconfigure.session.SessionAutoConfiguration,\

org.springframework.boot.autoconfigure.security.oauth2.client.servlet.OAuth2ClientAutoConfiguration,\

org.springframework.boot.autoconfigure.security.oauth2.client.reactive.ReactiveOAuth2ClientAutoConfiguration,\

org.springframework.boot.autoconfigure.security.oauth2.resource.servlet.OAuth2ResourceServerAutoConfiguration,\

org.springframework.boot.autoconfigure.security.oauth2.resource.reactive.ReactiveOAuth2ResourceServerAutoConfiguration,\

org.springframework.boot.autoconfigure.solr.SolrAutoConfiguration,\

org.springframework.boot.autoconfigure.task.TaskExecutionAutoConfiguration,\

org.springframework.boot.autoconfigure.task.TaskSchedulingAutoConfiguration,\

org.springframework.boot.autoconfigure.thymeleaf.ThymeleafAutoConfiguration,\

org.springframework.boot.autoconfigure.transaction.TransactionAutoConfiguration,\

org.springframework.boot.autoconfigure.transaction.jta.JtaAutoConfiguration,\

org.springframework.boot.autoconfigure.validation.ValidationAutoConfiguration,\

org.springframework.boot.autoconfigure.web.client.RestTemplateAutoConfiguration,\

org.springframework.boot.autoconfigure.web.embedded.EmbeddedWebServerFactoryCustomizerAutoConfiguration,\

org.springframework.boot.autoconfigure.web.reactive.HttpHandlerAutoConfiguration,\

org.springframework.boot.autoconfigure.web.reactive.ReactiveWebServerFactoryAutoConfiguration,\

org.springframework.boot.autoconfigure.web.reactive.WebFluxAutoConfiguration,\

org.springframework.boot.autoconfigure.web.reactive.error.ErrorWebFluxAutoConfiguration,\

org.springframework.boot.autoconfigure.web.reactive.function.client.ClientHttpConnectorAutoConfiguration,\

org.springframework.boot.autoconfigure.web.reactive.function.client.WebClientAutoConfiguration,\

org.springframework.boot.autoconfigure.web.servlet.DispatcherServletAutoConfiguration,\

org.springframework.boot.autoconfigure.web.servlet.ServletWebServerFactoryAutoConfiguration,\

org.springframework.boot.autoconfigure.web.servlet.error.ErrorMvcAutoConfiguration,\

org.springframework.boot.autoconfigure.web.servlet.HttpEncodingAutoConfiguration,\

org.springframework.boot.autoconfigure.web.servlet.MultipartAutoConfiguration,\

org.springframework.boot.autoconfigure.web.servlet.WebMvcAutoConfiguration,\

org.springframework.boot.autoconfigure.websocket.reactive.WebSocketReactiveAutoConfiguration,\

org.springframework.boot.autoconfigure.websocket.servlet.WebSocketServletAutoConfiguration,\

org.springframework.boot.autoconfigure.websocket.servlet.WebSocketMessagingAutoConfiguration,\

org.springframework.boot.autoconfigure.webservices.WebServicesAutoConfiguration,\

org.springframework.boot.autoconfigure.webservices.client.WebServiceTemplateAutoConfiguration
  • 我们常用的各种工具都已经封装好了
  • 比如redis: RedisAutoConfiguration
  • 比如mongo: MongoDataAutoConfiguration
  • 我们看看RedisAutoConfiguration
import org.springframework.data.redis.core.RedisOperations;

@Configuration(proxyBeanMethods = false)

@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;

	}

}
  • @EnableConfigurationProperties(RedisProperties.class)是加载配置的
  • @ConditionalOnClass(RedisOperations.class)是另一个开关，必须存在RedisOperations这个类
  • 方法是封装好的RedisTemplate
@ConfigurationProperties(prefix = "spring.redis")

public class RedisProperties {

	private int database = 0;

	private String url;

	private String host = "localhost";

	private String password;

	private int port = 6379;

	private boolean ssl;

	private Duration timeout;

	private String clientName;

	private Sentinel sentinel;

	private Cluster cluster;

    ...

}
  • RedisOperations这个类在哪呢？下面这个jar里面
<dependency>

    <groupId>org.springframework.data</groupId>

    <artifactId>spring-data-redis</artifactId>

</dependency>
  • 这个依赖又怎么加载进springboot呢？
<?xml version="1.0" encoding="UTF-8"?>

<project xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd" xmlns="http://maven.apache.org/POM/4.0.0"

    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">

  <modelVersion>4.0.0</modelVersion>

  <parent>

    <groupId>org.springframework.boot</groupId>

    <artifactId>spring-boot-starters</artifactId>

    <version>2.0.8.RELEASE</version>

  </parent>

  <groupId>org.springframework.boot</groupId>

  <artifactId>spring-boot-starter-data-redis</artifactId>

  <version>2.0.8.RELEASE</version>

  <name>Spring Boot Data Redis Starter</name>

  <description>Starter for using Redis key-value data store with Spring Data Redis and

		the Lettuce client</description>

  <url>https://projects.spring.io/spring-boot/#/spring-boot-parent/spring-boot-starters/spring-boot-starter-data-redis</url>

  <organization>

    <name>Pivotal Software, Inc.</name>

    <url>https://spring.io</url>

  </organization>

  <licenses>

    <license>

      <name>Apache License, Version 2.0</name>

      <url>http://www.apache.org/licenses/LICENSE-2.0</url>

    </license>

  </licenses>

  <developers>

    <developer>

      <name>Pivotal</name>

      <email>info@pivotal.io</email>

      <organization>Pivotal Software, Inc.</organization>

      <organizationUrl>http://www.spring.io</organizationUrl>

    </developer>

  </developers>

  <scm>

    <connection>scm:git:git://github.com/spring-projects/spring-boot.git/spring-boot-starters/spring-boot-starter-data-redis</connection>

    <developerConnection>scm:git:ssh://git@github.com/spring-projects/spring-boot.git/spring-boot-starters/spring-boot-starter-data-redis</developerConnection>

    <url>http://github.com/spring-projects/spring-boot/spring-boot-starters/spring-boot-starter-data-redis</url>

  </scm>

  <issueManagement>

    <system>Github</system>

    <url>https://github.com/spring-projects/spring-boot/issues</url>

  </issueManagement>

  <dependencies>

    <dependency>

      <groupId>org.springframework.boot</groupId>

      <artifactId>spring-boot-starter</artifactId>

      <version>2.0.8.RELEASE</version>

      <scope>compile</scope>

    </dependency>

    <dependency>

      <groupId>org.springframework.data</groupId>

      <artifactId>spring-data-redis</artifactId>

      <version>2.0.13.RELEASE</version>

      <scope>compile</scope>

      <exclusions>

        <exclusion>

          <artifactId>jcl-over-slf4j</artifactId>

          <groupId>org.slf4j</groupId>

        </exclusion>

      </exclusions>

    </dependency>

    <dependency>

      <groupId>io.lettuce</groupId>

      <artifactId>lettuce-core</artifactId>

      <version>5.0.5.RELEASE</version>

      <scope>compile</scope>

    </dependency>

  </dependencies>

</project>
  • spring-boot-starter-data-redis这个依赖里面有

到此，已经很清楚了，我们总结一下：

  • 通过@SpringBootApplication注解引入@EnableAutoConfiguration注解

  • 通过@EnableAutoConfiguration注解引入AutoConfigurationImportSelector

  • 进入AutoConfigurationImportSelector的selectImports方法

  • 通过SpringFactoriesLoader把所有的EnableAutoConfiguration加载进来

  • 这些自动装配的类还有一道@ConditionalOnClass拦着，必须加载相应的jar才能加载进springboot, 实现可插拔

  • 我们使用就两步，加载相应的依赖，写好配置

  • 目录：

    springboot源码解析-管中窥豹系列

欢迎关注微信公众号：丰极，更多技术学习分享。

springboot源码解析-管中窥豹系列之自动装配（九）的更多相关文章

  1. springboot源码解析-管中窥豹系列之BeanDefine如何加载（十三）

    一.前言 Springboot源码解析是一件大工程,逐行逐句的去研究代码,会很枯燥,也不容易坚持下去. 我们不追求大而全,而是试着每次去研究一个小知识点,最终聚沙成塔,这就是我们的springboot ...

  2. springboot源码解析-管中窥豹系列之BeanPostProcessor（十二）

    一.前言 Springboot源码解析是一件大工程,逐行逐句的去研究代码,会很枯燥,也不容易坚持下去. 我们不追求大而全,而是试着每次去研究一个小知识点,最终聚沙成塔,这就是我们的springboot ...

  3. springboot源码解析-管中窥豹系列之bean如何生成？（十四）

    一.前言 Springboot源码解析是一件大工程,逐行逐句的去研究代码,会很枯燥,也不容易坚持下去. 我们不追求大而全,而是试着每次去研究一个小知识点,最终聚沙成塔,这就是我们的springboot ...

  4. springboot源码解析-管中窥豹系列之BeanDefinition（八）

    一.前言 Springboot源码解析是一件大工程,逐行逐句的去研究代码,会很枯燥,也不容易坚持下去. 我们不追求大而全,而是试着每次去研究一个小知识点,最终聚沙成塔,这就是我们的springboot ...

  5. springboot源码解析-管中窥豹系列之EnableXXX（十）

    一.前言 Springboot源码解析是一件大工程,逐行逐句的去研究代码,会很枯燥,也不容易坚持下去. 我们不追求大而全,而是试着每次去研究一个小知识点,最终聚沙成塔,这就是我们的springboot ...

  6. springboot源码解析-管中窥豹系列之web服务器（七）

    一.前言 Springboot源码解析是一件大工程,逐行逐句的去研究代码,会很枯燥,也不容易坚持下去. 我们不追求大而全,而是试着每次去研究一个小知识点,最终聚沙成塔,这就是我们的springboot ...

  7. springboot源码解析-管中窥豹系列

    一.前言 Springboot源码解析是一件大工程,逐行逐句的去研究代码,会很枯燥,也不容易坚持下去. 我们不追求大而全,而是试着每次去研究一个小知识点,最终聚沙成塔,这就是我们的springboot ...

  8. springboot源码解析-管中窥豹系列之BeanFactoryPostProcessor（十一）

    一.前言 Springboot源码解析是一件大工程,逐行逐句的去研究代码,会很枯燥,也不容易坚持下去. 我们不追求大而全,而是试着每次去研究一个小知识点,最终聚沙成塔,这就是我们的springboot ...

  9. springboot源码解析-管中窥豹系列之项目类型（二）

    一.前言 Springboot源码解析是一件大工程,逐行逐句的去研究代码,会很枯燥,也不容易坚持下去. 我们不追求大而全,而是试着每次去研究一个小知识点,最终聚沙成塔,这就是我们的springboot ...

随机推荐

  1. CF-559C Gerald and Giant Chess（计数DP）

    给定一个 \(H*W\)的棋盘,棋盘上只有\(N\) 个格子是黑色的,其他格子都是白色的. 在棋盘左上角有一个卒,每一步可以向右或者向下移动一格,并且不能移动到黑色格子中.求这个卒从左上角移动到右下角 ...

  2. 2020年10月ICPC & 天梯赛 选拔赛【ACFJ】

    A. 表达式 题意 题解 将所有数字替换为A,运算符替换为O,然后不断合并(AOA),判断表达式最后是否为A即可. 注意将数字替换时判断有无前导零. 代码 #include <bits/stdc ...

  3. 牛客练习赛64 D【容斥+背包】

    牛客练习赛64 D.宝石装箱 Description \(n\)颗宝石装进\(n\)个箱子使得每个箱子中都有一颗宝石.第\(i\)颗宝石不能装入第\(a_i\)个箱子.求合法的装箱方案对\(99824 ...

  4. Windows10与虚拟机中CentOS-7.2进行telnet通信 出现在端口23处失败【解决】

    (telnet服务是由xinetd守护,所以安装和启动都要用到xinetd) 1.先检查CentOS7.0是否已经安装以下几个安装包:telnet-server.telnet.xinetd.命令如下: ...

  5. 【uva 1617】Laptop（算法效率--贪心，2种理解）

    题意:有N条长度为1的线段,要求使每条线段分别在相应区间,且"空隙"数目最小.输出"空隙"数.(1≤N≤100000) 解法:(P.S.我这题竟做了2个多小时, ...

  6. Codeforces Round #570 (Div. 3) G. Candy Box (hard version) (贪心,优先队列)

    题意:你有\(n\)个礼物,礼物有自己的种类,你想将它们按种类打包送人,但是打包的礼物数量必须不同(数量,与种类无关),同时,有些礼物你想自己留着,\(0\)表示你不想送人,问你在送出的礼物数量最大的 ...

  7. HDU 4289 Control(最大流+拆点，最小割点)

    题意: 有一群恐怖分子要从起点st到en城市集合,你要在路程中的城市阻止他们,使得他们全部都被抓到(当然st城市,en城市也可以抓捕).在每一个城市抓捕都有一个花费,你要找到花费最少是多少. 题解: ...

  8. CF1400-D. Zigzags

    CF1400-D. Zigzags 题意: 给出一个由\(n\)个数字构成的数组\(a\),让你在这个数组中找出有多少个符合以下要求的元组\((i,j,k,l)\): 1. \(i<j<k ...

  9. 【cpp上】课后正误小题

    State whether each of the following is true or false. If false, explain why. Assume the state ment u ...

  10. Ubuntu下跑通py-faster-rcnn、详解demo运作流程

    在不同的服务器不同的机器上做过很多次实验,分别遇到各种不一样的错误并且跑通Py-Faster-RCNN,因此,在这里做一个流程的汇总: 一.下载文件: 首先,文件的下载可以有两种途径: 1.需要在官网 ...