springboot日志文件名称为什么叫logback-spring.xml

如题，为什么springboot日志配置文件叫logback-spring.xml？

在整个项目中搜索 logback-spring.xml 并没有搜索到。

先看一下

org.springframework.boot.context.logging.LoggingApplicationListener#initialize

	protected void initialize(ConfigurableEnvironment environment, ClassLoader classLoader) {
		// 省略

		initializeSystem(environment, this.loggingSystem, this.logFile);

		// ... 省略
	}

会走到

org.springframework.boot.logging.AbstractLoggingSystem#initializeWithConventions

如下代码完成 日志配置文件的定位，最终获取到 logback-spring.xml日志配置文件咯

@Override
	protected String[] getStandardConfigLocations() {
		return new String[] { "logback-test.groovy", "logback-test.xml", "logback.groovy", "logback.xml" };
	}	


protected String[] getSpringConfigLocations() {
		String[] locations = getStandardConfigLocations();
		for (int i = 0; i < locations.length; i++) {
			String extension = StringUtils.getFilenameExtension(locations[i]);
			locations[i] = locations[i].substring(0, locations[i].length() - extension.length() - 1) + "-spring."
					+ extension;
		}
		return locations;
	}