Update metadata format to v2

Update the metadata format in a non backward compatible way to ease
the use of the service from 3rd party clients. The updated metadata
format is now more descriptive and HAL-compliant and can be used with
Spring HATEOAS to build a client.

Metadata v1 is still served to preserve backward compatibility with
Spring Boot 1.2.0.RC1.

Closes gh-49

initializr/pom.xml

@@ -30,6 +30,10 @@
 			<groupId>com.fasterxml.jackson.core</groupId>
 			<artifactId>jackson-core</artifactId>
 		</dependency>
+		<dependency>
+			<groupId>org.springframework.hateoas</groupId>
+			<artifactId>spring-hateoas</artifactId>
+		</dependency>
 		<dependency>
 			<groupId>com.google.guava</groupId>
 			<artifactId>guava</artifactId>

initializr/src/main/groovy/io/spring/initializr/InitializrMetadata.groovy

@@ -66,6 +66,8 @@ class InitializrMetadata {
 	@JsonIgnore
 	private final Map<String, Dependency> indexedDependencies = [:]
 
+	private final transient InitializrMetadataJsonMapper jsonMapper = new InitializrMetadataJsonMapper()
+
 	/**
 	 * Return the {@link Dependency} with the specified id or {@code null} if
 	 * no such dependency exists.
@@ -121,6 +123,15 @@ class InitializrMetadata {
 		refreshDefaults()
 	}
 
+	/**
+	 * Generate a JSON representation of the current metadata
+	 *
+	 * @param appUrl the application url
+	 */
+	String generateJson(String appUrl) {
+		jsonMapper.write(this, appUrl)
+	}
+
 	/**
 	 * Initialize and validate the configuration.
 	 */
@@ -261,6 +272,14 @@ class InitializrMetadata {
 
 		String action
 
+		void setAction(String action) {
+			String actionToUse = action
+			if (!actionToUse.startsWith("/")) {
+				actionToUse =  "/" +  actionToUse
+			}
+			this.action = actionToUse
+		}
+
 		final Map<String, String> tags = [:]
 	}
 

initializr/src/main/groovy/io/spring/initializr/InitializrMetadataJsonMapper.groovy

@@ -0,0 +1,168 @@
+/*
+ * 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 io.spring.initializr
+
+import groovy.json.JsonBuilder
+
+import org.springframework.hateoas.TemplateVariable
+import org.springframework.hateoas.TemplateVariables
+import org.springframework.hateoas.UriTemplate
+
+/**
+ * Generate a JSON representation of the metadata.
+ *
+ * @author Stephane Nicoll
+ * @since 1.0
+ */
+class InitializrMetadataJsonMapper {
+
+	private final TemplateVariables templateVariables
+
+	InitializrMetadataJsonMapper() {
+		this.templateVariables = new TemplateVariables(
+				new TemplateVariable('type', TemplateVariable.VariableType.REQUEST_PARAM),
+				new TemplateVariable('packaging', TemplateVariable.VariableType.REQUEST_PARAM),
+				new TemplateVariable('javaVersion', TemplateVariable.VariableType.REQUEST_PARAM),
+				new TemplateVariable('language', TemplateVariable.VariableType.REQUEST_PARAM),
+				new TemplateVariable('bootVersion', TemplateVariable.VariableType.REQUEST_PARAM),
+				new TemplateVariable('groupId', TemplateVariable.VariableType.REQUEST_PARAM),
+				new TemplateVariable('artifactId', TemplateVariable.VariableType.REQUEST_PARAM),
+				new TemplateVariable('version', TemplateVariable.VariableType.REQUEST_PARAM),
+				new TemplateVariable('name', TemplateVariable.VariableType.REQUEST_PARAM),
+				new TemplateVariable('description', TemplateVariable.VariableType.REQUEST_PARAM),
+				new TemplateVariable('packageName', TemplateVariable.VariableType.REQUEST_PARAM)
+		)
+	}
+
+	String write(InitializrMetadata metadata, String appUrl) {
+		JsonBuilder json = new JsonBuilder()
+		json {
+			links(delegate, metadata.types, appUrl)
+			dependencies(delegate, metadata.dependencies)
+			type(delegate, metadata.defaults.type, metadata.types)
+			singleSelect(delegate, 'packaging', metadata.defaults.packaging, metadata.packagings)
+			singleSelect(delegate, 'javaVersion', metadata.defaults.javaVersion, metadata.javaVersions)
+			singleSelect(delegate, 'language', metadata.defaults.language, metadata.languages)
+			singleSelect(delegate, 'bootVersion', metadata.defaults.bootVersion, metadata.bootVersions)
+			text(delegate, 'groupId', metadata.defaults.groupId)
+			text(delegate, 'artifactId', metadata.defaults.artifactId)
+			text(delegate, 'version', metadata.defaults.version)
+			text(delegate, 'name', metadata.defaults.name)
+			text(delegate, 'description', metadata.defaults.description)
+			text(delegate, 'packageName', metadata.defaults.packageName)
+		}
+		json.toString()
+	}
+
+	private links(parent, types, appUrl) {
+		def content = [:]
+		types.each {
+			content[it.id] = link(appUrl, it)
+		}
+		parent._links content
+	}
+
+	private link(appUrl, type) {
+		def result = [:]
+		result.href = generateTemplatedUri(appUrl, type.action)
+		result.templated = true
+		result
+	}
+
+	private generateTemplatedUri(appUrl, action) {
+		String uri = appUrl != null ? appUrl + action : action
+		UriTemplate uriTemplate = new UriTemplate(uri + '?style={dependencies}', this.templateVariables)
+		uriTemplate.toString()
+	}
+
+
+	private static dependencies(parent, groups) {
+		parent.dependencies {
+			type 'hierarchical-multi-select'
+			values groups.collect {
+				processDependencyGroup(it)
+			}
+		}
+
+	}
+
+	private static type(parent, defaultValue, dependencies) {
+		parent.type {
+			type 'action'
+			if (defaultValue) {
+				'default' defaultValue
+			}
+			values dependencies.collect {
+				processType(it)
+			}
+		}
+	}
+
+	private static singleSelect(parent, name, defaultValue, itemValues) {
+		parent."$name" {
+			type 'single-select'
+			if (defaultValue) {
+				'default' defaultValue
+			}
+			values itemValues.collect {
+				processValue(it)
+			}
+		}
+	}
+
+	private static text(parent, name, value) {
+		parent."$name" {
+			type 'text'
+			if (value) {
+				'default' value
+			}
+		}
+	}
+
+
+	private static processDependencyGroup(group) {
+		def result = [:]
+		result.name = group.name
+		if (group.hasProperty('description') && group.description) {
+			result.description = group.description
+		}
+		def items = []
+		group.content.collect {
+			items << processValue(it)
+		}
+		result.values = items
+		result
+	}
+
+	private static processType(type) {
+		def result = processValue(type)
+		result.action = type.action
+		result.tags = type.tags
+		result
+	}
+
+	private static processValue(value) {
+		def result = [:]
+		result.id = value.id
+		result.name = value.name
+		if (value.hasProperty('description') && value.description) {
+			result.description = value.description
+		}
+		result
+	}
+
+}

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

@@ -29,6 +29,7 @@ import org.springframework.stereotype.Controller
 import org.springframework.web.bind.annotation.ModelAttribute
 import org.springframework.web.bind.annotation.RequestMapping
 import org.springframework.web.bind.annotation.ResponseBody
+import org.springframework.web.servlet.support.ServletUriComponentsBuilder
 
 /**
  * The main initializr controller provides access to the configured
@@ -53,12 +54,20 @@ class MainController extends AbstractInitializrController {
 		request
 	}
 
-	@RequestMapping(value = "/")
+	@RequestMapping(value = "/", headers = "user-agent=SpringBootCli/1.2.0.RC1")
 	@ResponseBody
-	InitializrMetadata metadata() {
+	@Deprecated
+	InitializrMetadata oldMetadata() {
 		metadataProvider.get()
 	}
 
+	@RequestMapping(value = "/", produces = ["application/vnd.initializr.v2+json","application/json"])
+	@ResponseBody
+	String metadata() {
+		String appUrl = ServletUriComponentsBuilder.fromCurrentServletMapping().build()
+		metadataProvider.get().generateJson(appUrl)
+	}
+
 	@RequestMapping(value = '/', produces = 'text/html')
 	@ResponseBody
 	String home() {

initializr/src/test/groovy/io/spring/initializr/InitializrMetadataJsonMapperTests.groovy

@@ -0,0 +1,54 @@
+/*
+ * 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 io.spring.initializr
+
+import groovy.json.JsonSlurper
+import io.spring.initializr.support.InitializrMetadataBuilder
+import org.junit.Test
+
+import static org.junit.Assert.assertEquals
+
+/**
+ * @author Stephane Nicoll
+ */
+class InitializrMetadataJsonMapperTests {
+
+	private final InitializrMetadataJsonMapper jsonMapper = new InitializrMetadataJsonMapper()
+	private final JsonSlurper slurper = new JsonSlurper()
+
+	@Test
+	void withNoAppUrl() {
+		InitializrMetadata metadata = new InitializrMetadataBuilder().addType('foo', true, '/foo.zip', 'none', 'test')
+				.addDependencyGroup('foo', 'one', 'two').validateAndGet()
+		def json = jsonMapper.write(metadata, null)
+		def result = slurper.parseText(json)
+		assertEquals '/foo.zip?style={dependencies}{&type,packaging,javaVersion,language,bootVersion,' +
+				'groupId,artifactId,version,name,description,packageName}', result._links.foo.href
+	}
+
+	@Test
+	void withAppUrl() {
+		InitializrMetadata metadata = new InitializrMetadataBuilder().addType('foo', true, '/foo.zip', 'none', 'test')
+				.addDependencyGroup('foo', 'one', 'two').validateAndGet()
+		def json = jsonMapper.write(metadata, 'http://server:8080/my-app')
+		def result = slurper.parseText(json)
+		assertEquals 'http://server:8080/my-app/foo.zip?style={dependencies}{&type,packaging,javaVersion,' +
+				'language,bootVersion,groupId,artifactId,version,name,description,packageName}',
+				result._links.foo.href
+	}
+
+}

initializr/src/test/groovy/io/spring/initializr/InitializrMetadataTests.groovy

@@ -177,6 +177,13 @@ class InitializrMetadataTests {
 		assertEquals metadata.defaults.groupId, request.groupId
 	}
 
+	@Test
+	void validateAction() {
+		def metadata = new InitializrMetadataBuilder()
+				.addType('foo', false, 'my-action.zip', 'none', 'none').validateAndGet()
+		assertEquals '/my-action.zip', metadata.getType('foo').action
+	}
+
 	@Test
 	void validateArtifactRepository() {
 		def metadata = InitializrMetadataBuilder.withDefaults().instance()

initializr/src/test/groovy/io/spring/initializr/web/AbstractInitializrControllerIntegrationTests.groovy

@@ -50,7 +50,7 @@ abstract class AbstractInitializrControllerIntegrationTests {
 	public final TemporaryFolder folder = new TemporaryFolder()
 
 	@Value('${local.server.port}')
-	private int port
+	protected int port
 
 	final RestTemplate restTemplate = new RestTemplate()
 

initializr/src/test/groovy/io/spring/initializr/web/MainControllerIntegrationTests.groovy

@@ -26,7 +26,11 @@ import org.skyscreamer.jsonassert.JSONAssert
 import org.skyscreamer.jsonassert.JSONCompareMode
 
 import org.springframework.core.io.ClassPathResource
+import org.springframework.http.HttpEntity
+import org.springframework.http.HttpHeaders
+import org.springframework.http.HttpMethod
 import org.springframework.http.HttpStatus
+import org.springframework.http.MediaType
 import org.springframework.http.ResponseEntity
 import org.springframework.test.context.ActiveProfiles
 import org.springframework.util.StreamUtils
@@ -40,8 +44,10 @@ import static org.junit.Assert.*
 @ActiveProfiles('test-default')
 class MainControllerIntegrationTests extends AbstractInitializrControllerIntegrationTests {
 
-	private final def slurper = new JsonSlurper()
+	private static final MediaType CURRENT_METADATA_MEDIA_TYPE =
+			MediaType.parseMediaType('application/vnd.initializr.v2+json')
 
+	private final def slurper = new JsonSlurper()
 
 	@Test
 	void simpleZipProject() {
@@ -104,25 +110,50 @@ class MainControllerIntegrationTests extends AbstractInitializrControllerIntegra
 
 	}
 
+	@Test
+	void metadataWithNoAcceptHeader() { //  rest template sets application/json by default
+		ResponseEntity<String> response = getMetadata(null, '*/*')
+		assertEquals CURRENT_METADATA_MEDIA_TYPE, response.getHeaders().getContentType()
+		validateCurrentMetadata(new JSONObject(response.body))
+	}
+
+	@Test
+	void metadataWithCurrentAcceptHeader() {
+		ResponseEntity<String> response = getMetadata(null, 'application/vnd.initializr.v2+json')
+		assertEquals CURRENT_METADATA_MEDIA_TYPE, response.getHeaders().getContentType()
+		validateCurrentMetadata(new JSONObject(response.body))
+	}
+
 	@Test // Test that the current output is exactly what we expect
 	void validateCurrentProjectMetadata() {
-		def json = restTemplate.getForObject(createUrl('/'), String.class)
-		def expected = readJson('1.1.0')
-		JSONAssert.assertEquals(expected, new JSONObject(json), JSONCompareMode.STRICT)
+		def json = getMetadataJson()
+		validateCurrentMetadata(json)
+	}
+
+	private void validateCurrentMetadata(JSONObject json) {
+		def expected = readJson('2.0.0')
+		JSONAssert.assertEquals(expected, json, JSONCompareMode.STRICT)
+	}
+
+	@Test // Test that the  current code complies exactly with 1.1.0
+	void validateProjectMetadata110() {
+		JSONObject json = getMetadataJson("SpringBootCli/1.2.0.RC1", null)
+		def expected = readJson('1.0.1')
+		JSONAssert.assertEquals(expected, json, JSONCompareMode.LENIENT)
 	}
 
 	@Test // Test that the  current code complies "at least" with 1.0.1
 	void validateProjectMetadata101() {
-		def json = restTemplate.getForObject(createUrl('/'), String.class)
+		JSONObject json = getMetadataJson("SpringBootCli/1.2.0.RC1", null)
 		def expected = readJson('1.0.1')
-		JSONAssert.assertEquals(expected, new JSONObject(json), JSONCompareMode.LENIENT)
+		JSONAssert.assertEquals(expected, json, JSONCompareMode.LENIENT)
 	}
 
 	@Test // Test that the  current code complies "at least" with 1.0.0
 	void validateProjectMetadata100() {
-		def json = restTemplate.getForObject(createUrl('/'), String.class)
+		JSONObject json = getMetadataJson("SpringBootCli/1.2.0.RC1", null)
 		def expected = readJson('1.0.0')
-		JSONAssert.assertEquals(expected, new JSONObject(json), JSONCompareMode.LENIENT)
+		JSONAssert.assertEquals(expected, json, JSONCompareMode.LENIENT)
 	}
 
 	@Test
@@ -186,7 +217,7 @@ class MainControllerIntegrationTests extends AbstractInitializrControllerIntegra
 	@Test
 	void homeIsJson() {
 		def body = restTemplate.getForObject(createUrl('/'), String)
-		assertTrue("Wrong body:\n$body", body.contains('{"dependencies"'))
+		assertTrue("Wrong body:\n$body", body.contains('"dependencies"'))
 	}
 
 	@Test
@@ -237,6 +268,27 @@ class MainControllerIntegrationTests extends AbstractInitializrControllerIntegra
 		assertNotNull(response.body)
 	}
 
+	private JSONObject getMetadataJson()  {
+		getMetadataJson(null, null)
+	}
+
+	private JSONObject getMetadataJson(String userAgentHeader, String acceptHeader) {
+		String json = getMetadata(userAgentHeader, acceptHeader).body
+		return new JSONObject(json)
+	}
+
+	private ResponseEntity<String> getMetadata(String userAgentHeader, String acceptHeader) {
+		HttpHeaders headers = new HttpHeaders();
+		if (userAgentHeader) {
+			headers.set("User-Agent", userAgentHeader);
+		}
+		if (acceptHeader) {
+			headers.setAccept(Collections.singletonList(MediaType.parseMediaType(acceptHeader)))
+		}
+		return restTemplate.exchange(createUrl('/'),
+				HttpMethod.GET, new HttpEntity<Void>(headers), String.class)
+	}
+
 
 	private byte[] invoke(String context) {
 		restTemplate.getForObject(createUrl(context), byte[])
@@ -252,12 +304,15 @@ class MainControllerIntegrationTests extends AbstractInitializrControllerIntegra
 		tgzProjectAssert(body)
 	}
 
-	private static JSONObject readJson(String version) {
+	private JSONObject readJson(String version) {
 		def resource = new ClassPathResource("metadata/test-default-$version" + ".json")
 		def stream = resource.inputStream
 		try {
 			def json = StreamUtils.copyToString(stream, Charset.forName('UTF-8'))
-			new JSONObject(json)
+
+			// Let's parse the port as it is random
+			def content = json.replaceAll('@port@', String.valueOf(this.port))
+			new JSONObject(content)
 		} finally {
 			stream.close()
 		}

initializr/src/test/resources/metadata/test-default-2.0.0.json

@@ -0,0 +1,186 @@
+{
+  "_links": {
+    "maven-build": {
+      "href": "http://localhost:@port@/pom.xml?style={dependencies}{&type,packaging,javaVersion,language,bootVersion,groupId,artifactId,version,name,description,packageName}",
+      "templated": true
+    },
+    "maven-project": {
+      "href": "http://localhost:@port@/starter.zip?style={dependencies}{&type,packaging,javaVersion,language,bootVersion,groupId,artifactId,version,name,description,packageName}",
+      "templated": true
+    },
+    "gradle-build": {
+      "href": "http://localhost:@port@/build.gradle?style={dependencies}{&type,packaging,javaVersion,language,bootVersion,groupId,artifactId,version,name,description,packageName}",
+      "templated": true
+    },
+    "gradle-project": {
+      "href": "http://localhost:@port@/starter.zip?style={dependencies}{&type,packaging,javaVersion,language,bootVersion,groupId,artifactId,version,name,description,packageName}",
+      "templated": true
+    }
+  },
+  "dependencies": {
+    "type": "hierarchical-multi-select",
+    "values": [
+      {
+        "name": "Core",
+        "values": [
+          {
+            "id": "web",
+            "name": "Web",
+            "description": "Web dependency description"
+          },
+          {
+            "id": "security",
+            "name": "Security"
+          },
+          {
+            "id": "data-jpa",
+            "name": "Data JPA"
+          }
+        ]
+      },
+      {
+        "name": "Other",
+        "values": [
+          {
+            "id": "org.acme:foo",
+            "name": "Foo"
+          },
+          {
+            "id": "org.acme:bar",
+            "name": "Bar"
+          }
+        ]
+      }
+    ]
+  },
+  "type": {
+    "type": "action",
+    "default": "maven-project",
+    "values": [
+      {
+        "id": "maven-build",
+        "name": "Maven POM",
+        "action": "/pom.xml",
+        "tags": {
+          "build": "maven",
+          "format": "build"
+        }
+      },
+      {
+        "id": "maven-project",
+        "name": "Maven Project",
+        "action": "/starter.zip",
+        "tags": {
+          "build": "maven",
+          "format": "project"
+        }
+      },
+      {
+        "id": "gradle-build",
+        "name": "Gradle Config",
+        "action": "/build.gradle",
+        "tags": {
+          "build": "gradle",
+          "format": "build"
+        }
+      },
+      {
+        "id": "gradle-project",
+        "name": "Gradle Project",
+        "action": "/starter.zip",
+        "tags": {
+          "build": "gradle",
+          "format": "project"
+        }
+      }
+    ]
+  },
+  "packaging": {
+    "type": "single-select",
+    "default": "jar",
+    "values": [
+      {
+        "id": "jar",
+        "name": "Jar"
+      },
+      {
+        "id": "war",
+        "name": "War"
+      }
+    ]
+  },
+  "javaVersion": {
+    "type": "single-select",
+    "default": "1.7",
+    "values": [
+      {
+        "id": "1.6",
+        "name": "1.6"
+      },
+      {
+        "id": "1.7",
+        "name": "1.7"
+      },
+      {
+        "id": "1.8",
+        "name": "1.8"
+      }
+    ]
+  },
+  "language": {
+    "type": "single-select",
+    "default": "java",
+    "values": [
+      {
+        "id": "groovy",
+        "name": "Groovy"
+      },
+      {
+        "id": "java",
+        "name": "Java"
+      }
+    ]
+  },
+  "bootVersion": {
+    "type": "single-select",
+    "default": "1.1.4.RELEASE",
+    "values": [
+      {
+        "id": "1.2.0.BUILD-SNAPSHOT",
+        "name": "Latest SNAPSHOT"
+      },
+      {
+        "id": "1.1.4.RELEASE",
+        "name": "1.1.4"
+      },
+      {
+        "id": "1.0.2.RELEASE",
+        "name": "1.0.2"
+      }
+    ]
+  },
+  "groupId": {
+    "type": "text",
+    "default": "org.test"
+  },
+  "artifactId": {
+    "type": "text",
+    "default": "demo"
+  },
+  "version": {
+    "type": "text",
+    "default": "0.0.1-SNAPSHOT"
+  },
+  "name": {
+    "type": "text",
+    "default": "demo"
+  },
+  "description": {
+    "type": "text",
+    "default": "Demo project for Spring Boot"
+  },
+  "packageName": {
+    "type": "text",
+    "default": "demo"
+  }
+}