core/src/main/java/org/springframework/security/core/SpringSecurityCoreVersion.java
private static String getSpringVersion() {
		Properties properties = new Properties();
		try {
			properties.load(SpringSecurityCoreVersion.class.getClassLoader().getResourceAsStream("META-INF/spring-security.versions"));
		} catch (IOException | NullPointerException e) {
			return null;
		}
		return properties.getProperty("org.springframework:spring-core");
	}
private static String getSpringVersion() {
		Properties properties = new Properties();
		try {
			properties.load(SpringSecurityCoreVersion.class.getClassLoader().getResourceAsStream("META-INF/spring-security.versions"));
		} catch (IOException | NullPointerException e) {
			return null;
		}
		return properties.getProperty("org.springframework:spring-core");
	}
Loads the spring version or null if it cannot be found.
@return