OnJndiCondition Class — spring-boot Architecture

Source Code

core/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/condition/OnJndiCondition.java lines 40–110

@Order(Ordered.LOWEST_PRECEDENCE - 20)
class OnJndiCondition extends SpringBootCondition {

	@Override
	public ConditionOutcome getMatchOutcome(ConditionContext context, AnnotatedTypeMetadata metadata) {
		AnnotationAttributes attributes = AnnotationAttributes
			.fromMap(metadata.getAnnotationAttributes(ConditionalOnJndi.class.getName()));
		Assert.state(attributes != null, "'attributes' must not be null");
		String[] locations = attributes.getStringArray("value");
		try {
			return getMatchOutcome(locations);
		}
		catch (NoClassDefFoundError ex) {
			return ConditionOutcome
				.noMatch(ConditionMessage.forCondition(ConditionalOnJndi.class).because("JNDI class not found"));
		}
	}

	private ConditionOutcome getMatchOutcome(String[] locations) {
		if (!isJndiAvailable()) {
			return ConditionOutcome
				.noMatch(ConditionMessage.forCondition(ConditionalOnJndi.class).notAvailable("JNDI environment"));
		}
		if (locations.length == 0) {
			return ConditionOutcome
				.match(ConditionMessage.forCondition(ConditionalOnJndi.class).available("JNDI environment"));
		}
		JndiLocator locator = getJndiLocator(locations);
		String location = locator.lookupFirstLocation();
		String details = "(" + StringUtils.arrayToCommaDelimitedString(locations) + ")";
		if (location != null) {
			return ConditionOutcome.match(ConditionMessage.forCondition(ConditionalOnJndi.class, details)
				.foundExactly("\"" + location + "\""));
		}
		return ConditionOutcome.noMatch(ConditionMessage.forCondition(ConditionalOnJndi.class, details)
			.didNotFind("any matching JNDI location")
			.atAll());
	}

	protected boolean isJndiAvailable() {
		return JndiLocatorDelegate.isDefaultJndiEnvironmentAvailable();
	}

	protected JndiLocator getJndiLocator(String[] locations) {
		return new JndiLocator(locations);
	}

	protected static class JndiLocator extends JndiLocatorSupport {

		private final String[] locations;

		public JndiLocator(String[] locations) {
			this.locations = locations;
		}

		public @Nullable String lookupFirstLocation() {
			for (String location : this.locations) {
				try {
					lookup(location);
					return location;
				}
				catch (NamingException ex) {
					// Swallow and continue
				}
			}
			return null;
		}

	}

}