java

关注公众号 jb51net

关闭
首页 > 软件编程 > java > SpringBoot 创建容器

SpringBoot 创建容器的实现

作者:jiao个朋友

这篇文章主要介绍了SpringBoot 创建容器的实现,文中通过示例代码介绍的非常详细,对大家的学习或者工作具有一定的参考学习价值,需要的朋友们下面随着小编来一起学习学习吧

spring 容器的创建对应 SpringApplication 中 run 中调用的 createApplicationContext 方法。这里创建了一个 web 容器,接下就进去 prepareContext 容器准备阶段:

  private void prepareContext(ConfigurableApplicationContext context, ConfigurableEnvironment environment,
      SpringApplicationRunListeners listeners, ApplicationArguments applicationArguments, Banner printedBanner) {
    //为容器设置环境
    context.setEnvironment(environment);
    //这里的空实现留给开发者扩展,设置数据转换的ConversionService
    postProcessApplicationContext(context);
    //执行容器中的 Initializers 的 initialize 方法
    applyInitializers(context);
    listeners.contextPrepared(context);
    if (this.logStartupInfo) {
      logStartupInfo(context.getParent() == null);
      logStartupProfileInfo(context);
    }
    // Add boot specific singleton beans
    ConfigurableListableBeanFactory beanFactory = context.getBeanFactory();
    beanFactory.registerSingleton("springApplicationArguments", applicationArguments);
    if (printedBanner != null) {
      beanFactory.registerSingleton("springBootBanner", printedBanner);
    }
    if (beanFactory instanceof DefaultListableBeanFactory) {
      ((DefaultListableBeanFactory) beanFactory)
          .setAllowBeanDefinitionOverriding(this.allowBeanDefinitionOverriding);
    }
    if (this.lazyInitialization) {
      context.addBeanFactoryPostProcessor(new LazyInitializationBeanFactoryPostProcessor());
    }
    // Load the sources
    Set<Object> sources = getAllSources();
    Assert.notEmpty(sources, "Sources must not be empty");
    load(context, sources.toArray(new Object[0]));
    listeners.contextLoaded(context);
  }

看一下这里的 load 方法,这里主要把我们的启动类作为 Bean 注册到了 Spring 的容器中。

  protected void load(ApplicationContext context, Object[] sources) {
    if (logger.isDebugEnabled()) {
      logger.debug("Loading source " + StringUtils.arrayToCommaDelimitedString(sources));
    }
    BeanDefinitionLoader loader = createBeanDefinitionLoader(getBeanDefinitionRegistry(context), sources);
    if (this.beanNameGenerator != null) {
      loader.setBeanNameGenerator(this.beanNameGenerator);
    }
    if (this.resourceLoader != null) {
      loader.setResourceLoader(this.resourceLoader);
    }
    if (this.environment != null) {
      loader.setEnvironment(this.environment);
    }
    loader.load();
  }

  /**
   * Load the sources into the reader.
   * @return the number of loaded beans
   */
  int load() {
    int count = 0;
    for (Object source : this.sources) {
      count += load(source);
    }
    return count;
  }

  private int load(Object source) {
    Assert.notNull(source, "Source must not be null");
    if (source instanceof Class<?>) {
      return load((Class<?>) source);
    }
    if (source instanceof Resource) {
      return load((Resource) source);
    }
    if (source instanceof Package) {
      return load((Package) source);
    }
    if (source instanceof CharSequence) {
      return load((CharSequence) source);
    }
    throw new IllegalArgumentException("Invalid source type " + source.getClass());
  }

  private int load(Class<?> source) {
    if (isGroovyPresent() && GroovyBeanDefinitionSource.class.isAssignableFrom(source)) {
      // Any GroovyLoaders added in beans{} DSL can contribute beans here
      GroovyBeanDefinitionSource loader = BeanUtils.instantiateClass(source, GroovyBeanDefinitionSource.class);
      load(loader);
    }
    if (isEligible(source)) {
      this.annotatedReader.register(source);
      return 1;
    }
    return 0;
  }

再来看下 contextLoaded 方法,这里将上下文设置到监听器中,同时也把监听器添加到上下文中。最后发布了一个 ApplicationPreparedEvent 事件。

  public void contextLoaded(ConfigurableApplicationContext context) {
    for (ApplicationListener<?> listener : this.application.getListeners()) {
      if (listener instanceof ApplicationContextAware) {
        ((ApplicationContextAware) listener).setApplicationContext(context);
      }
      context.addApplicationListener(listener);
    }
    this.initialMulticaster.multicastEvent(new ApplicationPreparedEvent(this.application, this.args, context));
  }

到此这篇关于SpringBoot 创建容器的实现的文章就介绍到这了,更多相关SpringBoot 创建容器内容请搜索脚本之家以前的文章或继续浏览下面的相关文章希望大家以后多多支持脚本之家!

您可能感兴趣的文章:
阅读全文