PathBasedTemplateAvailabilityProvider Class — spring-boot Architecture

Source Code

core/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/template/PathBasedTemplateAvailabilityProvider.java lines 35–104

public abstract class PathBasedTemplateAvailabilityProvider implements TemplateAvailabilityProvider {

	private final String className;

	private final Class<TemplateAvailabilityProperties> propertiesClass;

	private final String propertyPrefix;

	@SuppressWarnings("unchecked")
	public PathBasedTemplateAvailabilityProvider(String className,
			Class<? extends TemplateAvailabilityProperties> propertiesClass, String propertyPrefix) {
		this.className = className;
		this.propertiesClass = (Class<TemplateAvailabilityProperties>) propertiesClass;
		this.propertyPrefix = propertyPrefix;
	}

	@Override
	public boolean isTemplateAvailable(String view, Environment environment, ClassLoader classLoader,
			ResourceLoader resourceLoader) {
		if (ClassUtils.isPresent(this.className, classLoader)) {
			Binder binder = Binder.get(environment);
			TemplateAvailabilityProperties properties = binder.bindOrCreate(this.propertyPrefix, this.propertiesClass);
			return isTemplateAvailable(view, resourceLoader, properties);
		}
		return false;
	}

	private boolean isTemplateAvailable(String view, ResourceLoader resourceLoader,
			TemplateAvailabilityProperties properties) {
		String location = properties.getPrefix() + view + properties.getSuffix();
		for (String path : properties.getLoaderPath()) {
			if (resourceLoader.getResource(path + location).exists()) {
				return true;
			}
		}
		return false;
	}

	protected abstract static class TemplateAvailabilityProperties {

		private String prefix;

		private String suffix;

		protected TemplateAvailabilityProperties(String prefix, String suffix) {
			this.prefix = prefix;
			this.suffix = suffix;
		}

		protected abstract List<String> getLoaderPath();

		public String getPrefix() {
			return this.prefix;
		}

		public void setPrefix(String prefix) {
			this.prefix = prefix;
		}

		public String getSuffix() {
			return this.suffix;
		}

		public void setSuffix(String suffix) {
			this.suffix = suffix;
		}

	}

}