AutoConfigurationMetadataLoader Class — spring-boot Architecture

Source Code

core/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/AutoConfigurationMetadataLoader.java lines 36–117

final class AutoConfigurationMetadataLoader {

	private static final String PATH = "META-INF/spring-autoconfigure-metadata.properties";

	private AutoConfigurationMetadataLoader() {
	}

	static AutoConfigurationMetadata loadMetadata(ClassLoader classLoader) {
		return loadMetadata(classLoader, PATH);
	}

	static AutoConfigurationMetadata loadMetadata(@Nullable ClassLoader classLoader, String path) {
		try {
			Enumeration<URL> urls = (classLoader != null) ? classLoader.getResources(path)
					: ClassLoader.getSystemResources(path);
			Properties properties = new Properties();
			while (urls.hasMoreElements()) {
				properties.putAll(PropertiesLoaderUtils.loadProperties(new UrlResource(urls.nextElement())));
			}
			return loadMetadata(properties);
		}
		catch (IOException ex) {
			throw new IllegalArgumentException("Unable to load @ConditionalOnClass location [" + path + "]", ex);
		}
	}

	static AutoConfigurationMetadata loadMetadata(Properties properties) {
		return new PropertiesAutoConfigurationMetadata(properties);
	}

	/**
	 * {@link AutoConfigurationMetadata} implementation backed by a properties file.
	 */
	private static class PropertiesAutoConfigurationMetadata implements AutoConfigurationMetadata {

		private final Properties properties;

		PropertiesAutoConfigurationMetadata(Properties properties) {
			this.properties = properties;
		}

		@Override
		public boolean wasProcessed(String className) {
			return this.properties.containsKey(className);
		}

		@Override
		public @Nullable Integer getInteger(String className, String key) {
			return getInteger(className, key, null);
		}

		@Override
		public @Nullable Integer getInteger(String className, String key, @Nullable Integer defaultValue) {
			String value = get(className, key);
			return (value != null) ? Integer.valueOf(value) : defaultValue;
		}

		@Override
		public @Nullable Set<String> getSet(String className, String key) {
			return getSet(className, key, null);
		}

		@Override
		public @Nullable Set<String> getSet(String className, String key, @Nullable Set<String> defaultValue) {
			String value = get(className, key);
			return (value != null) ? StringUtils.commaDelimitedListToSet(value) : defaultValue;
		}

		@Override
		public @Nullable String get(String className, String key) {
			return get(className, key, null);
		}

		@Override
		public @Nullable String get(String className, String key, @Nullable String defaultValue) {
			String value = this.properties.getProperty(className + "." + key);
			return (value != null) ? value : defaultValue;
		}

	}

}