Cache templates

This commit improves massively class loading performance by caching all
templates used by the generator. GroovyTemplate is now a bean rather than
a private utility.

Templates are cached by default and the cache is disabled automatically
if Devtools is in use (via a check of spring.groovy.template.cache).

Closes gh-288

initializr-web/src/main/groovy/io/spring/initializr/web/autoconfigure/InitializrAutoConfiguration.groovy

@@ -27,6 +27,7 @@ import io.spring.initializr.metadata.DependencyMetadataProvider
 import io.spring.initializr.metadata.InitializrMetadataBuilder
 import io.spring.initializr.metadata.InitializrMetadataProvider
 import io.spring.initializr.metadata.InitializrProperties
+import io.spring.initializr.util.GroovyTemplate
 import io.spring.initializr.web.project.MainController
 import io.spring.initializr.web.support.DefaultDependencyMetadataProvider
 import io.spring.initializr.web.support.DefaultInitializrMetadataProvider
@@ -34,6 +35,7 @@ import io.spring.initializr.web.ui.UiController
 
 import org.springframework.beans.factory.annotation.Autowired
 import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean
+import org.springframework.boot.bind.RelaxedPropertyResolver
 import org.springframework.boot.context.properties.EnableConfigurationProperties
 import org.springframework.cache.Cache
 import org.springframework.cache.CacheManager
@@ -43,6 +45,7 @@ import org.springframework.cache.concurrent.ConcurrentMapCache
 import org.springframework.cache.support.SimpleCacheManager
 import org.springframework.context.annotation.Bean
 import org.springframework.context.annotation.Configuration
+import org.springframework.core.env.Environment
 import org.springframework.web.client.RestTemplate
 
 /**
@@ -72,8 +75,11 @@ class InitializrAutoConfiguration {
 
 	@Bean
 	@ConditionalOnMissingBean
-	MainController initializrMainController() {
-		new MainController()
+	MainController initializrMainController(InitializrMetadataProvider metadataProvider,
+											GroovyTemplate groovyTemplate,
+											ProjectGenerator projectGenerator,
+											DependencyMetadataProvider dependencyMetadataProvider) {
+		new MainController(metadataProvider, groovyTemplate, projectGenerator, dependencyMetadataProvider)
 	}
 
 	@Bean
@@ -88,6 +94,16 @@ class InitializrAutoConfiguration {
 		new ProjectGenerator()
 	}
 
+	@Bean
+	@ConditionalOnMissingBean
+	GroovyTemplate groovyTemplate(Environment environment) {
+		def resolver = new RelaxedPropertyResolver(environment, 'spring.groovy.template.')
+		boolean cache = resolver.getProperty('cache', Boolean.class, true)
+		def groovyTemplate = new GroovyTemplate()
+		groovyTemplate.cache = cache
+		groovyTemplate
+	}
+
 	@Bean
 	@ConditionalOnMissingBean
 	ProjectRequestResolver projectRequestResolver() {

initializr-web/src/main/groovy/io/spring/initializr/web/project/AbstractInitializrController.groovy

@@ -21,14 +21,12 @@ import javax.servlet.http.HttpServletResponse
 
 import io.spring.initializr.generator.InvalidProjectRequestException
 import io.spring.initializr.metadata.InitializrMetadataProvider
+import io.spring.initializr.util.GroovyTemplate
 
-import org.springframework.beans.factory.annotation.Autowired
 import org.springframework.http.HttpStatus
 import org.springframework.web.bind.annotation.ExceptionHandler
 import org.springframework.web.servlet.support.ServletUriComponentsBuilder
 
-import static io.spring.initializr.util.GroovyTemplate.template
-
 /**
  * A base controller that uses a {@link InitializrMetadataProvider}
  *
@@ -37,11 +35,16 @@ import static io.spring.initializr.util.GroovyTemplate.template
  */
 abstract class AbstractInitializrController {
 
-	@Autowired
-	protected InitializrMetadataProvider metadataProvider
-
+	protected final InitializrMetadataProvider metadataProvider
+	private final GroovyTemplate groovyTemplate
 	private boolean forceSsl
 
+	protected AbstractInitializrController(InitializrMetadataProvider metadataProvider,
+										   GroovyTemplate groovyTemplate) {
+		this.metadataProvider = metadataProvider
+		this.groovyTemplate = groovyTemplate
+	}
+
 	@PostConstruct
 	void initialize() {
 		forceSsl = metadataProvider.get().configuration.env.forceSsl
@@ -74,7 +77,7 @@ abstract class AbstractInitializrController {
 		// Google analytics support
 		model['trackingCode'] = metadata.configuration.env.googleAnalyticsTrackingCode
 
-		template templatePath, model
+		groovyTemplate.process templatePath, model
 	}
 
 	/**

initializr-web/src/main/groovy/io/spring/initializr/web/project/LegacyStsController.groovy

@@ -16,6 +16,9 @@
 
 package io.spring.initializr.web.project
 
+import io.spring.initializr.metadata.InitializrMetadataProvider
+import io.spring.initializr.util.GroovyTemplate
+
 import org.springframework.stereotype.Controller
 import org.springframework.web.bind.annotation.RequestMapping
 import org.springframework.web.bind.annotation.ResponseBody
@@ -30,6 +33,10 @@ import org.springframework.web.bind.annotation.ResponseBody
 @Deprecated
 class LegacyStsController extends AbstractInitializrController {
 
+	LegacyStsController(InitializrMetadataProvider metadataProvider, GroovyTemplate groovyTemplate) {
+		super(metadataProvider, groovyTemplate)
+	}
+
 	@RequestMapping(value = '/sts', produces = 'text/html')
 	@ResponseBody
 	String stsHome() {

initializr-web/src/main/groovy/io/spring/initializr/web/project/MainController.groovy

@@ -24,7 +24,9 @@ import io.spring.initializr.generator.BasicProjectRequest
 import io.spring.initializr.generator.CommandLineHelpGenerator
 import io.spring.initializr.generator.ProjectGenerator
 import io.spring.initializr.generator.ProjectRequest
+import io.spring.initializr.metadata.InitializrMetadataProvider
 import io.spring.initializr.util.Agent
+import io.spring.initializr.util.GroovyTemplate
 import io.spring.initializr.web.mapper.DependencyMetadataV21JsonMapper
 import io.spring.initializr.web.mapper.InitializrMetadataJsonMapper
 import io.spring.initializr.web.mapper.InitializrMetadataV21JsonMapper
@@ -67,14 +69,17 @@ class MainController extends AbstractInitializrController {
 
 	static final MediaType HAL_JSON_CONTENT_TYPE = MediaType.parseMediaType('application/hal+json')
 
-	@Autowired
-	private ProjectGenerator projectGenerator
-
-	@Autowired
-	private DependencyMetadataProvider dependencyMetadataProvider
-
-	private CommandLineHelpGenerator commandLineHelpGenerator = new CommandLineHelpGenerator()
+	private final ProjectGenerator projectGenerator
+	private final DependencyMetadataProvider dependencyMetadataProvider
+	private final CommandLineHelpGenerator commandLineHelpGenerator
 
+	MainController(InitializrMetadataProvider metadataProvider, GroovyTemplate groovyTemplate,
+				   ProjectGenerator projectGenerator, DependencyMetadataProvider dependencyMetadataProvider) {
+		super(metadataProvider, groovyTemplate)
+		this.projectGenerator = projectGenerator
+		this.dependencyMetadataProvider = dependencyMetadataProvider
+		this.commandLineHelpGenerator = new CommandLineHelpGenerator(groovyTemplate)
+	}
 
 	@ModelAttribute
 	BasicProjectRequest projectRequest(@RequestHeader Map<String,String> headers) {