Error Class — spring-boot Architecture

Source Code

core/spring-boot/src/main/java/org/springframework/boot/web/error/Error.java lines 40–121

public final class Error implements MessageSourceResolvable {

	private final MessageSourceResolvable cause;

	/**
	 * Create a new {@code Error} instance with the specified cause.
	 * @param cause the error cause (must not be {@code null})
	 */
	private Error(MessageSourceResolvable cause) {
		Assert.notNull(cause, "'cause' must not be null");
		this.cause = cause;
	}

	@Override
	public String @Nullable [] getCodes() {
		return this.cause.getCodes();
	}

	@Override
	public Object @Nullable [] getArguments() {
		return this.cause.getArguments();
	}

	@Override
	public @Nullable String getDefaultMessage() {
		return this.cause.getDefaultMessage();
	}

	/**
	 * Return the original cause of the error.
	 * @return the error cause
	 */
	@JsonIgnore
	public MessageSourceResolvable getCause() {
		return this.cause;
	}

	@Override
	public boolean equals(Object obj) {
		if (this == obj) {
			return true;
		}
		if (obj == null || getClass() != obj.getClass()) {
			return false;
		}
		return Objects.equals(this.cause, ((Error) obj).cause);
	}

	@Override
	public int hashCode() {
		return Objects.hash(this.cause);
	}

	@Override
	public String toString() {
		return this.cause.toString();
	}

	/**
	 * Wrap the given errors, if necessary, such that they are suitable for serialization
	 * to JSON. {@link MessageSourceResolvable} implementations that are known to be
	 * suitable are not wrapped.
	 * @param errors the errors to wrap
	 * @return a new Error list
	 * @since 3.5.4
	 */
	public static List<MessageSourceResolvable> wrapIfNecessary(List<? extends MessageSourceResolvable> errors) {
		if (CollectionUtils.isEmpty(errors)) {
			return Collections.emptyList();
		}
		List<MessageSourceResolvable> result = new ArrayList<>(errors.size());
		for (MessageSourceResolvable error : errors) {
			result.add(requiresWrapping(error) ? new Error(error) : error);
		}
		return List.copyOf(result);
	}

	private static boolean requiresWrapping(MessageSourceResolvable error) {
		return !(error instanceof ObjectError);
	}

}