Add support for FreeMarker in non-webapp

The existing freemarker support only works in a webapp. This
change adds a FreeMarker Configuration bean (in both web- and
non webapps) so it can be used to load a Template and render it
(e.g. with Spring's FreeMarkerTemplateUtils).

See gh-679

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

@@ -25,8 +25,10 @@ import javax.servlet.Servlet;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.autoconfigure.AutoConfigureAfter;
 import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnBean;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnNotWebApplication;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnWebApplication;
 import org.springframework.boot.autoconfigure.web.WebMvcAutoConfiguration;
 import org.springframework.boot.bind.RelaxedPropertyResolver;
@@ -38,7 +40,9 @@ import org.springframework.core.env.Environment;
 import org.springframework.core.io.DefaultResourceLoader;
 import org.springframework.core.io.Resource;
 import org.springframework.core.io.ResourceLoader;
+import org.springframework.ui.freemarker.FreeMarkerConfigurationFactoryBean;
 import org.springframework.util.Assert;
+import org.springframework.web.servlet.view.freemarker.FreeMarkerConfig;
 import org.springframework.web.servlet.view.freemarker.FreeMarkerConfigurer;
 import org.springframework.web.servlet.view.freemarker.FreeMarkerViewResolver;
 
@@ -86,10 +90,25 @@ public class FreeMarkerAutoConfiguration {
 			}
 		}
 
+	}
+
+	@Configuration
+	@ConditionalOnClass(Servlet.class)
+	@ConditionalOnNotWebApplication
+	public static class FreeMarkerConfiguration implements EnvironmentAware {
+
+		private RelaxedPropertyResolver environment;
+
+		@Override
+		public void setEnvironment(Environment environment) {
+			this.environment = new RelaxedPropertyResolver(environment,
+					"spring.freemarker.");
+		}
+
 		@Bean
-		@ConditionalOnMissingBean(name = "freeMarkerConfigurer")
-		public FreeMarkerConfigurer freeMarkerConfigurer() {
-			FreeMarkerConfigurer freeMarkerConfigurer = new FreeMarkerConfigurer();
+		@ConditionalOnMissingBean
+		public FreeMarkerConfigurationFactoryBean freeMarkerConfigurer() {
+			FreeMarkerConfigurationFactoryBean freeMarkerConfigurer = new FreeMarkerConfigurationFactoryBean();
 			freeMarkerConfigurer.setTemplateLoaderPath(this.environment.getProperty(
 					"templateLoaderPath", DEFAULT_TEMPLATE_LOADER_PATH));
 			freeMarkerConfigurer.setDefaultEncoding(this.environment.getProperty(
@@ -101,6 +120,7 @@ public class FreeMarkerAutoConfiguration {
 			freeMarkerConfigurer.setFreemarkerSettings(settings);
 			return freeMarkerConfigurer;
 		}
+
 	}
 
 	@Configuration
@@ -116,6 +136,30 @@ public class FreeMarkerAutoConfiguration {
 					"spring.freemarker.");
 		}
 
+		@Bean
+		@ConditionalOnBean(FreeMarkerConfig.class)
+		@ConditionalOnMissingBean
+		public freemarker.template.Configuration freemarkerConfiguration(
+				FreeMarkerConfig configurer) {
+			return configurer.getConfiguration();
+		}
+
+		@Bean
+		@ConditionalOnMissingBean
+		public FreeMarkerConfigurer freeMarkerConfigurer() {
+			FreeMarkerConfigurer freeMarkerConfigurer = new FreeMarkerConfigurer();
+			freeMarkerConfigurer.setTemplateLoaderPath(this.environment.getProperty(
+					"templateLoaderPath", DEFAULT_TEMPLATE_LOADER_PATH));
+			freeMarkerConfigurer.setDefaultEncoding(this.environment.getProperty(
+					"templateEncoding", "UTF-8"));
+			Map<String, Object> settingsMap = this.environment
+					.getSubProperties("settings.");
+			Properties settings = new Properties();
+			settings.putAll(settingsMap);
+			freeMarkerConfigurer.setFreemarkerSettings(settings);
+			return freeMarkerConfigurer;
+		}
+
 		@Bean
 		@ConditionalOnMissingBean(name = "freeMarkerViewResolver")
 		public FreeMarkerViewResolver freeMarkerViewResolver() {

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

@@ -17,6 +17,7 @@
 package org.springframework.boot.autoconfigure.freemarker;
 
 import java.io.File;
+import java.io.StringWriter;
 import java.util.Locale;
 
 import javax.servlet.http.HttpServletRequest;
@@ -186,6 +187,21 @@ public class FreeMarkerAutoConfigurationTests {
 				.getConfiguration().getSetting("boolean_format"));
 	}
 
+	@Test
+	public void renderTemplate() throws Exception {
+		this.context.register(FreeMarkerAutoConfiguration.class);
+		this.context.refresh();
+		freemarker.template.Configuration freemarker = this.context
+				.getBean(freemarker.template.Configuration.class);
+		StringWriter writer = new StringWriter();
+		freemarker.getTemplate("message.ftl").process(this, writer);
+		assertTrue("Wrong content: " + writer, writer.toString().contains("Hello World"));
+	}
+
+	public String getGreeting() {
+		return "Hello World";
+	}
+
 	private MockHttpServletResponse render(String viewName) throws Exception {
 
 		View view = this.context.getBean(FreeMarkerViewResolver.class).resolveViewName(

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

@@ -0,0 +1,57 @@
+/*
+ * Copyright 2012-2014 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.boot.autoconfigure.freemarker;
+
+import java.io.StringWriter;
+
+import org.junit.After;
+import org.junit.Test;
+import org.springframework.context.annotation.AnnotationConfigApplicationContext;
+
+import static org.junit.Assert.assertTrue;
+
+/**
+ * Tests for {@link FreeMarkerAutoConfiguration}.
+ * 
+ * @author Andy Wilkinson
+ */
+public class FreeMarkerNonWebappTests {
+
+	private AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext();
+
+	@After
+	public void close() {
+		if (this.context != null) {
+			this.context.close();
+		}
+	}
+
+	@Test
+	public void renderTemplate() throws Exception {
+		this.context.register(FreeMarkerAutoConfiguration.class);
+		this.context.refresh();
+		freemarker.template.Configuration freemarker = this.context
+				.getBean(freemarker.template.Configuration.class);
+		StringWriter writer = new StringWriter();
+		freemarker.getTemplate("message.ftl").process(this, writer);
+		assertTrue("Wrong content: " + writer, writer.toString().contains("Hello World"));
+	}
+
+	public String getGreeting() {
+		return "Hello World";
+	}
+}

spring-boot-autoconfigure/src/test/resources/templates/message.ftl

@@ -0,0 +1 @@
+Message: ${greeting}