Allow multiple templateLoaderPaths to be configured for FreeMarker

Closes gh-1767

spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/freemarker/FreeMarkerAutoConfiguration.java

@@ -16,6 +16,8 @@
 
 package org.springframework.boot.autoconfigure.freemarker;
 
+import java.util.ArrayList;
+import java.util.List;
 import java.util.Properties;
 
 import javax.annotation.PostConstruct;
@@ -65,10 +67,18 @@ public class FreeMarkerAutoConfiguration {
 	@PostConstruct
 	public void checkTemplateLocationExists() {
 		if (this.properties.isCheckTemplateLocation()) {
-			Resource resource = this.resourceLoader.getResource(this.properties
-					.getTemplateLoaderPath());
-			Assert.state(resource.exists(), "Cannot find template location: " + resource
-					+ " (please add some templates, "
+			Resource templatePathResource = null;
+			List<Resource> resources = new ArrayList<Resource>();
+			for (String templateLoaderPath : this.properties.getTemplateLoaderPath()) {
+				Resource resource = this.resourceLoader.getResource(templateLoaderPath);
+				resources.add(resource);
+				if (resource.exists()) {
+					templatePathResource = resource;
+					break;
+				}
+			}
+			Assert.notNull(templatePathResource, "Cannot find template location(s): "
+					+ resources + " (please add some templates, "
 					+ "check your FreeMarker configuration, or set "
 					+ "spring.freemarker.checkTemplateLocation=false)");
 		}
@@ -80,7 +90,7 @@ public class FreeMarkerAutoConfiguration {
 		protected FreeMarkerProperties properties;
 
 		protected void applyProperties(FreeMarkerConfigurationFactory factory) {
-			factory.setTemplateLoaderPath(this.properties.getTemplateLoaderPath());
+			factory.setTemplateLoaderPaths(this.properties.getTemplateLoaderPath());
 			factory.setDefaultEncoding(this.properties.getCharSet());
 			Properties settings = new Properties();
 			settings.putAll(this.properties.getSettings());

spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/freemarker/FreeMarkerProperties.java

@@ -40,7 +40,7 @@ public class FreeMarkerProperties extends AbstractTemplateViewResolverProperties
 
 	private Map<String, String> settings = new HashMap<String, String>();
 
-	private String templateLoaderPath = DEFAULT_TEMPLATE_LOADER_PATH;
+	private String[] templateLoaderPath = new String[] { DEFAULT_TEMPLATE_LOADER_PATH };
 
 	public FreeMarkerProperties() {
 		super(DEFAULT_PREFIX, DEFAULT_SUFFIX);
@@ -54,12 +54,12 @@ public class FreeMarkerProperties extends AbstractTemplateViewResolverProperties
 		this.settings = settings;
 	}
 
-	public String getTemplateLoaderPath() {
+	public String[] getTemplateLoaderPath() {
 		return this.templateLoaderPath;
 	}
 
-	public void setTemplateLoaderPath(String templateLoaderPath) {
-		this.templateLoaderPath = templateLoaderPath;
+	public void setTemplateLoaderPath(String... templateLoaderPaths) {
+		this.templateLoaderPath = templateLoaderPaths;
 	}
 
 }

spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/freemarker/FreeMarkerAutoConfigurationTests.java

@@ -73,7 +73,7 @@ public class FreeMarkerAutoConfigurationTests {
 	@Test(expected = BeanCreationException.class)
 	public void nonExistentTemplateLocation() {
 		registerAndRefreshContext("spring.freemarker.templateLoaderPath:"
-				+ "classpath:/does-not-exist/");
+				+ "classpath:/does-not-exist/,classpath:/also-does-not-exist");
 	}
 
 	@Test
@@ -83,6 +83,13 @@ public class FreeMarkerAutoConfigurationTests {
 				+ "classpath:/templates/empty-directory/");
 	}
 
+	@Test
+	public void nonExistentLocationAndEmptyLocation() {
+		new File("target/test-classes/templates/empty-directory").mkdir();
+		registerAndRefreshContext("spring.freemarker.templateLoaderPath:"
+				+ "classpath:/does-not-exist/,classpath:/templates/empty-directory/");
+	}
+
 	@Test
 	public void defaultViewResolution() throws Exception {
 		registerAndRefreshContext();

spring-boot-docs/src/main/asciidoc/appendix-application-properties.adoc

@@ -123,7 +123,7 @@ content into your application; rather pick only the properties that you need.
 	spring.freemarker.requestContextAttribute=
 	spring.freemarker.settings.*=
 	spring.freemarker.suffix=.ftl
-	spring.freemarker.templateLoaderPath=classpath:/templates/
+	spring.freemarker.templateLoaderPath=classpath:/templates/ # comma-separated list
 	spring.freemarker.viewNames= # whitelist of view names that can be resolved
 
 	# GROOVY TEMPLATES ({sc-spring-boot-autoconfigure}/groovy/template/GroovyTemplateAutoConfiguration.{sc-ext}[GroovyTemplateAutoConfiguration])