Spec Class — spring-boot Architecture

Source Code

core/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/condition/OnPropertyCondition.java lines 118–209

	private static class Spec {

		private final Class<? extends Annotation> annotationType;

		private final String prefix;

		private final String[] names;

		private final String havingValue;

		private final boolean matchIfMissing;

		Spec(Class<? extends Annotation> annotationType, AnnotationAttributes annotationAttributes) {
			this.annotationType = annotationType;
			this.prefix = (!annotationAttributes.containsKey("prefix")) ? "" : getPrefix(annotationAttributes);
			this.names = getNames(annotationAttributes);
			this.havingValue = getHavingValue(annotationAttributes);
			this.matchIfMissing = annotationAttributes.getBoolean("matchIfMissing");
		}

		private static String getHavingValue(AnnotationAttributes annotationAttributes) {
			Object havingValue = annotationAttributes.get("havingValue");
			Assert.state(havingValue != null, "'havingValue' must not be null");
			return havingValue.toString();
		}

		private String getPrefix(AnnotationAttributes annotationAttributes) {
			String prefix = annotationAttributes.getString("prefix").trim();
			if (StringUtils.hasText(prefix) && !prefix.endsWith(".")) {
				prefix = prefix + ".";
			}
			return prefix;
		}

		private String[] getNames(AnnotationAttributes annotationAttributes) {
			String[] value = (String[]) annotationAttributes.get("value");
			String[] name = (String[]) annotationAttributes.get("name");
			Assert.state(value != null, "'value' must not be null");
			Assert.state(name != null, "'name' must not be null");
			Assert.state(value.length > 0 || name.length > 0,
					() -> "The name or value attribute of @%s must be specified"
						.formatted(ClassUtils.getShortName(this.annotationType)));
			Assert.state(value.length == 0 || name.length == 0,
					() -> "The name and value attributes of @%s are exclusive"
						.formatted(ClassUtils.getShortName(this.annotationType)));
			return (value.length > 0) ? value : name;
		}

		private void collectProperties(PropertyResolver resolver, List<String> missing, List<String> nonMatching) {
			for (String name : this.names) {
				String key = this.prefix + name;
				if (resolver.containsProperty(key)) {
					if (!isMatch(resolver.getProperty(key), this.havingValue)) {
						nonMatching.add(name);
					}
				}
				else {
					if (!this.matchIfMissing) {
						missing.add(name);
					}
				}
			}
		}

		private boolean isMatch(@Nullable String value, String requiredValue) {
			if (StringUtils.hasLength(requiredValue)) {
				return requiredValue.equalsIgnoreCase(value);
			}
			return !"false".equalsIgnoreCase(value);
		}

		@Override
		public String toString() {
			StringBuilder result = new StringBuilder();
			result.append("(");
			result.append(this.prefix);
			if (this.names.length == 1) {
				result.append(this.names[0]);
			}
			else {
				result.append("[");
				result.append(StringUtils.arrayToCommaDelimitedString(this.names));
				result.append("]");
			}
			if (StringUtils.hasLength(this.havingValue)) {
				result.append("=").append(this.havingValue);
			}
			result.append(")");
			return result.toString();
		}

	}