ContributorIterator Class — spring-boot Architecture

Source Code

core/spring-boot/src/main/java/org/springframework/boot/context/config/ConfigDataEnvironmentContributor.java lines 547–603

	private final class ContributorIterator implements Iterator<ConfigDataEnvironmentContributor> {

		private @Nullable ImportPhase phase;

		private Iterator<ConfigDataEnvironmentContributor> children;

		private Iterator<ConfigDataEnvironmentContributor> current;

		private @Nullable ConfigDataEnvironmentContributor next;

		private ContributorIterator() {
			this.phase = ImportPhase.AFTER_PROFILE_ACTIVATION;
			this.children = getChildren(this.phase).iterator();
			this.current = Collections.emptyIterator();
		}

		@Override
		public boolean hasNext() {
			return fetchIfNecessary() != null;
		}

		@Override
		public ConfigDataEnvironmentContributor next() {
			ConfigDataEnvironmentContributor next = fetchIfNecessary();
			if (next == null) {
				throw new NoSuchElementException();
			}
			this.next = null;
			return next;
		}

		private @Nullable ConfigDataEnvironmentContributor fetchIfNecessary() {
			if (this.next != null) {
				return this.next;
			}
			if (this.current.hasNext()) {
				this.next = this.current.next();
				return this.next;
			}
			if (this.children.hasNext()) {
				this.current = this.children.next().iterator();
				return fetchIfNecessary();
			}
			if (this.phase == ImportPhase.AFTER_PROFILE_ACTIVATION) {
				this.phase = ImportPhase.BEFORE_PROFILE_ACTIVATION;
				this.children = getChildren(this.phase).iterator();
				return fetchIfNecessary();
			}
			if (this.phase == ImportPhase.BEFORE_PROFILE_ACTIVATION) {
				this.phase = null;
				this.next = ConfigDataEnvironmentContributor.this;
				return this.next;
			}
			return null;
		}

	}