Support of spring initializr meta-data v2.1

Update the `init` command to support the latest meta-data format. Recent
Spring Initializr version also supports Spring Boot CLI now and generates
a textual service capabilities when requested. The command no longer
generates the capabilities of the service unless said service does not
support it.

Closes gh-2515

spring-boot-cli/src/main/java/org/springframework/boot/cli/command/init/InitializrService.java

@@ -48,6 +48,19 @@ class InitializrService {
 
 	private static final Charset UTF_8 = Charset.forName("UTF-8");
 
+	/**
+	 * Accept header to use to retrieve the json meta-data.
+	 */
+	public static final String ACCEPT_META_DATA =
+			"application/vnd.initializr.v2.1+json,application/vnd.initializr.v2+json";
+
+	/**
+	 * Accept header to use to retrieve the service capabilities of the service. If the
+	 * service does not offer such feature, the json meta-data are retrieved instead.
+	 */
+	public static final String ACCEPT_SERVICE_CAPABILITIES =
+			"text/plain," + ACCEPT_META_DATA;
+
 	/**
 	 * Late binding HTTP client.
 	 */
@@ -80,12 +93,7 @@ class InitializrService {
 		URI url = request.generateUrl(metadata);
 		CloseableHttpResponse httpResponse = executeProjectGenerationRequest(url);
 		HttpEntity httpEntity = httpResponse.getEntity();
-		if (httpEntity == null) {
-			throw new ReportableException("No content received from server '" + url + "'");
-		}
-		if (httpResponse.getStatusLine().getStatusCode() != 200) {
-			throw createException(request.getServiceUrl(), httpResponse);
-		}
+		validateResponse(httpResponse, request.getServiceUrl());
 		return createResponse(httpResponse, httpEntity);
 	}
 
@@ -97,6 +105,42 @@ class InitializrService {
 	 */
 	public InitializrServiceMetadata loadMetadata(String serviceUrl) throws IOException {
 		CloseableHttpResponse httpResponse = executeInitializrMetadataRetrieval(serviceUrl);
+		validateResponse(httpResponse, serviceUrl);
+		return parseJsonMetadata(httpResponse.getEntity());
+	}
+
+	/**
+	 * Loads the service capabilities of the service at the specified url.
+	 * <p>If the service supports generating a textual representation of the
+	 * capabilities, it is returned. Otherwhise the json meta-data as a
+	 * {@link JSONObject} is returned.
+	 * @param serviceUrl to url of the initializer service
+	 * @return the service capabilities (as a String) or the metadata describing the service
+	 * @throws IOException if the service capabilities cannot be loaded
+	 */
+	public Object loadServiceCapabilities(String serviceUrl) throws IOException  {
+		CloseableHttpResponse httpResponse = executeServiceCapabilitiesRetrieval(serviceUrl);
+		validateResponse(httpResponse, serviceUrl);
+		HttpEntity httpEntity = httpResponse.getEntity();
+		ContentType contentType = ContentType.getOrDefault(httpEntity);
+		if (contentType.getMimeType().equals("text/plain")) {
+			return  getContent(httpEntity);
+		} else {
+			return parseJsonMetadata(httpEntity);
+		}
+	}
+
+	private InitializrServiceMetadata parseJsonMetadata(HttpEntity httpEntity) throws IOException {
+		try {
+			return new InitializrServiceMetadata(getContentAsJson(httpEntity));
+		}
+		catch (JSONException ex) {
+			throw new ReportableException("Invalid content received from server ("
+					+ ex.getMessage() + ")", ex);
+		}
+	}
+
+	private void validateResponse(CloseableHttpResponse httpResponse, String serviceUrl) {
 		if (httpResponse.getEntity() == null) {
 			throw new ReportableException("No content received from server '"
 					+ serviceUrl + "'");
@@ -104,14 +148,6 @@ class InitializrService {
 		if (httpResponse.getStatusLine().getStatusCode() != 200) {
 			throw createException(serviceUrl, httpResponse);
 		}
-		try {
-			HttpEntity httpEntity = httpResponse.getEntity();
-			return new InitializrServiceMetadata(getContentAsJson(httpEntity));
-		}
-		catch (JSONException ex) {
-			throw new ReportableException("Invalid content received from server ("
-					+ ex.getMessage() + ")", ex);
-		}
 	}
 
 	private ProjectGenerationResponse createResponse(CloseableHttpResponse httpResponse,
@@ -139,11 +175,19 @@ class InitializrService {
 	 */
 	private CloseableHttpResponse executeInitializrMetadataRetrieval(String url) {
 		HttpGet request = new HttpGet(url);
-		request.setHeader(new BasicHeader(HttpHeaders.ACCEPT,
-				"application/vnd.initializr.v2+json"));
+		request.setHeader(new BasicHeader(HttpHeaders.ACCEPT, ACCEPT_META_DATA));
 		return execute(request, url, "retrieve metadata");
 	}
 
+	/**
+	 * Retrieves the service capabilities of the service at the specified URL
+	 */
+	private CloseableHttpResponse executeServiceCapabilitiesRetrieval(String url) {
+		HttpGet request = new HttpGet(url);
+		request.setHeader(new BasicHeader(HttpHeaders.ACCEPT, ACCEPT_SERVICE_CAPABILITIES));
+		return execute(request, url, "retrieve help");
+	}
+
 	private CloseableHttpResponse execute(HttpUriRequest request, Object url,
 			String description) {
 		try {
@@ -188,11 +232,15 @@ class InitializrService {
 	}
 
 	private JSONObject getContentAsJson(HttpEntity entity) throws IOException {
+		return new JSONObject(getContent(entity));
+	}
+
+	private String getContent(HttpEntity entity) throws IOException {
 		ContentType contentType = ContentType.getOrDefault(entity);
 		Charset charset = contentType.getCharset();
 		charset = (charset != null ? charset : UTF_8);
 		byte[] content = FileCopyUtils.copyToByteArray(entity.getContent());
-		return new JSONObject(new String(content, charset));
+		return new String(content, charset);
 	}
 
 	private String extractFileName(Header header) {

spring-boot-cli/src/main/java/org/springframework/boot/cli/command/init/ServiceCapabilitiesReportGenerator.java

@@ -54,7 +54,15 @@ class ServiceCapabilitiesReportGenerator {
 	 * @throws IOException if the report cannot be generated
 	 */
 	public String generate(String url) throws IOException {
-		InitializrServiceMetadata metadata = this.initializrService.loadMetadata(url);
+		Object content = this.initializrService.loadServiceCapabilities(url);
+		if (content instanceof InitializrServiceMetadata) {
+			return generateHelp(url, (InitializrServiceMetadata) content);
+		} else {
+			return content.toString();
+		}
+	}
+
+	private String generateHelp(String url, InitializrServiceMetadata metadata) {
 		String header = "Capabilities of " + url;
 		StringBuilder report = new StringBuilder();
 		report.append(StringUtils.repeat("=", header.length()) + NEW_LINE);

spring-boot-cli/src/test/java/org/springframework/boot/cli/command/init/AbstractHttpClientMockTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2014 the original author or authors.
+ * Copyright 2012-2015 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.
@@ -48,37 +48,51 @@ public abstract class AbstractHttpClientMockTests {
 
 	protected final CloseableHttpClient http = mock(CloseableHttpClient.class);
 
-	protected void mockSuccessfulMetadataGet() throws IOException {
-		mockSuccessfulMetadataGet("2.0.0");
+	protected void mockSuccessfulMetadataTextGet() throws IOException {
+		mockSuccessfulMetadataGet("metadata/service-metadata-2.1.0.txt", "text/plain", true);
 	}
 
-	protected void mockSuccessfulMetadataGet(String version) throws IOException {
+	protected void mockSuccessfulMetadataGet(boolean serviceCapabilities) throws IOException {
+		mockSuccessfulMetadataGet("metadata/service-metadata-2.1.0.json",
+				"application/vnd.initializr.v2.1+json", serviceCapabilities);
+	}
+
+	protected void mockSuccessfulMetadataGetV2(boolean serviceCapabilities) throws IOException {
+		mockSuccessfulMetadataGet("metadata/service-metadata-2.0.0.json",
+				"application/vnd.initializr.v2+json", serviceCapabilities);
+	}
+
+	protected void mockSuccessfulMetadataGet(String contentPath, String contentType,
+			boolean serviceCapabilities) throws IOException {
 		CloseableHttpResponse response = mock(CloseableHttpResponse.class);
-		Resource resource = new ClassPathResource("metadata/service-metadata-" + version
-				+ ".json");
-		byte[] content = StreamUtils.copyToByteArray(resource.getInputStream());
-		mockHttpEntity(response, content, "application/vnd.initializr.v2+json");
+		byte[] content = readClasspathResource(contentPath);
+		mockHttpEntity(response, content, contentType);
 		mockStatus(response, 200);
-		given(this.http.execute(argThat(getForJsonMetadata()))).willReturn(response);
+		given(this.http.execute(argThat(getForMetadata(serviceCapabilities)))).willReturn(response);
+	}
+
+	protected byte[] readClasspathResource(String contentPath) throws IOException {
+		Resource resource = new ClassPathResource(contentPath);
+		return StreamUtils.copyToByteArray(resource.getInputStream());
 	}
 
 	protected void mockSuccessfulProjectGeneration(
 			MockHttpProjectGenerationRequest request) throws IOException {
 		// Required for project generation as the metadata is read first
-		mockSuccessfulMetadataGet();
+		mockSuccessfulMetadataGet(false);
 		CloseableHttpResponse response = mock(CloseableHttpResponse.class);
 		mockHttpEntity(response, request.content, request.contentType);
 		mockStatus(response, 200);
 		String header = (request.fileName != null ? contentDispositionValue(request.fileName)
 				: null);
 		mockHttpHeader(response, "Content-Disposition", header);
-		given(this.http.execute(argThat(getForNonJsonMetadata()))).willReturn(response);
+		given(this.http.execute(argThat(getForNonMetadata()))).willReturn(response);
 	}
 
 	protected void mockProjectGenerationError(int status, String message)
 			throws IOException {
 		// Required for project generation as the metadata is read first
-		mockSuccessfulMetadataGet();
+		mockSuccessfulMetadataGet(false);
 		CloseableHttpResponse response = mock(CloseableHttpResponse.class);
 		mockHttpEntity(response, createJsonError(status, message).getBytes(),
 				"application/json");
@@ -122,12 +136,17 @@ public abstract class AbstractHttpClientMockTests {
 		given(response.getFirstHeader(headerName)).willReturn(header);
 	}
 
-	protected Matcher<HttpGet> getForJsonMetadata() {
-		return new HasAcceptHeader("application/vnd.initializr.v2+json", true);
+	private Matcher<HttpGet> getForMetadata(boolean serviceCapabilities) {
+		if (serviceCapabilities) {
+			return new HasAcceptHeader(InitializrService.ACCEPT_SERVICE_CAPABILITIES, true);
+		}
+		else {
+			return new HasAcceptHeader(InitializrService.ACCEPT_META_DATA, true);
+		}
 	}
 
-	protected Matcher<HttpGet> getForNonJsonMetadata() {
-		return new HasAcceptHeader("application/vnd.initializr.v2+json", false);
+	private Matcher<HttpGet> getForNonMetadata() {
+		return new HasAcceptHeader(InitializrService.ACCEPT_META_DATA, false);
 	}
 
 	private String contentDispositionValue(String fileName) {

spring-boot-cli/src/test/java/org/springframework/boot/cli/command/init/InitCommandTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2014 the original author or authors.
+ * Copyright 2012-2015 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.
@@ -73,9 +73,21 @@ public class InitCommandTests extends AbstractHttpClientMockTests {
 		this.command = new InitCommand(this.handler);
 	}
 
+	@Test
+	public void listServiceCapabilitiesText() throws Exception {
+		mockSuccessfulMetadataTextGet();
+		this.command.run("--list", "--target=http://fake-service");
+	}
+
 	@Test
 	public void listServiceCapabilities() throws Exception {
-		mockSuccessfulMetadataGet();
+		mockSuccessfulMetadataGet(true);
+		this.command.run("--list", "--target=http://fake-service");
+	}
+
+	@Test
+	public void listServiceCapabilitiesV2() throws Exception {
+		mockSuccessfulMetadataGetV2(true);
 		this.command.run("--list", "--target=http://fake-service");
 	}
 

spring-boot-cli/src/test/java/org/springframework/boot/cli/command/init/InitializrServiceTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2014 the original author or authors.
+ * Copyright 2012-2015 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.
@@ -46,7 +46,7 @@ public class InitializrServiceTests extends AbstractHttpClientMockTests {
 
 	@Test
 	public void loadMetadata() throws IOException {
-		mockSuccessfulMetadataGet();
+		mockSuccessfulMetadataGet(false);
 		InitializrServiceMetadata metadata = this.invoker.loadMetadata("http://foo/bar");
 		assertNotNull(metadata);
 	}
@@ -101,7 +101,7 @@ public class InitializrServiceTests extends AbstractHttpClientMockTests {
 
 	@Test
 	public void generateProjectNoContent() throws IOException {
-		mockSuccessfulMetadataGet();
+		mockSuccessfulMetadataGet(false);
 		CloseableHttpResponse response = mock(CloseableHttpResponse.class);
 		mockStatus(response, 500);
 		when(this.http.execute(isA(HttpGet.class))).thenReturn(response);

spring-boot-cli/src/test/java/org/springframework/boot/cli/command/init/ServiceCapabilitiesReportGeneratorTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2014 the original author or authors.
+ * Copyright 2012-2015 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.
@@ -20,7 +20,9 @@ import java.io.IOException;
 
 import org.junit.Test;
 
-import static org.junit.Assert.assertTrue;
+import static org.hamcrest.CoreMatchers.equalTo;
+import static org.hamcrest.core.StringContains.containsString;
+import static org.junit.Assert.assertThat;
 
 /**
  * Tests for {@link ServiceCapabilitiesReportGenerator}
@@ -33,13 +35,31 @@ public class ServiceCapabilitiesReportGeneratorTests extends AbstractHttpClientM
 			new InitializrService(this.http));
 
 	@Test
-	public void listMetadata() throws IOException {
-		mockSuccessfulMetadataGet();
+	public void listMetadataFromServer() throws IOException {
+		mockSuccessfulMetadataTextGet();
+		String expected = new String(readClasspathResource("metadata/service-metadata-2.1.0.txt"));
 		String content = this.command.generate("http://localhost");
-		assertTrue(content.contains("aop - AOP"));
-		assertTrue(content.contains("security - Security: Security description"));
-		assertTrue(content.contains("type: maven-project"));
-		assertTrue(content.contains("packaging: jar"));
+		assertThat(content, equalTo(expected));
+	}
+
+	@Test
+	public void listMetadata() throws IOException {
+		mockSuccessfulMetadataGet(true);
+		doTestGenerateCapabilitiesFromJson();
+	}
+
+	@Test
+	public void listMetadataV2() throws IOException {
+		mockSuccessfulMetadataGetV2(true);
+		doTestGenerateCapabilitiesFromJson();
+	}
+
+	private void doTestGenerateCapabilitiesFromJson() throws IOException {
+		String content = this.command.generate("http://localhost");
+		assertThat(content, containsString("aop - AOP"));
+		assertThat(content, containsString("security - Security: Security description"));
+		assertThat(content, containsString("type: maven-project"));
+		assertThat(content, containsString("packaging: jar"));
 	}
 
 }

spring-boot-cli/src/test/resources/metadata/service-metadata-2.1.0.json

@@ -0,0 +1,191 @@
+{
+	"_links": {
+		"maven-build": {
+			"href": "http://localhost:8080/pom.xml?type=maven-build{&dependencies,packaging,javaVersion,language,bootVersion,groupId,artifactId,version,name,description,packageName}",
+			"templated": true
+		},
+		"maven-project": {
+			"href": "http://localhost:8080/starter.zip?type=maven-project{&dependencies,packaging,javaVersion,language,bootVersion,groupId,artifactId,version,name,description,packageName}",
+			"templated": true
+		},
+		"gradle-build": {
+			"href": "http://localhost:8080/build.gradle?type=gradle-build{&dependencies,packaging,javaVersion,language,bootVersion,groupId,artifactId,version,name,description,packageName}",
+			"templated": true
+		},
+		"gradle-project": {
+			"href": "http://localhost:8080/starter.zip?type=gradle-project{&dependencies,packaging,javaVersion,language,bootVersion,groupId,artifactId,version,name,description,packageName}",
+			"templated": true
+		}
+	},
+	"dependencies": {
+		"type": "hierarchical-multi-select",
+		"values": [
+			{
+				"name": "Core",
+				"values": [
+					{
+						"name": "Security",
+						"id": "security",
+						"description": "Security description"
+					},
+					{
+						"name": "AOP",
+						"id": "aop"
+					}
+				]
+			},
+			{
+				"name": "Data",
+				"values": [
+					{
+						"name": "JDBC",
+						"id": "jdbc"
+					},
+					{
+						"name": "JPA",
+						"id": "data-jpa"
+					},
+					{
+						"name": "MongoDB",
+						"id": "data-mongodb",
+					    "versionRange": "1.1.7.RELEASE"
+					}
+				]
+			}
+		]
+	},
+	"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": "1.1.8.RELEASE",
+		"values": [
+			{
+				"id": "1.2.0.BUILD-SNAPSHOT",
+				"name": "1.2.0 (SNAPSHOT)"
+			},
+			{
+				"id": "1.1.8.RELEASE",
+				"name": "1.1.8"
+			},
+			{
+				"id": "1.1.8.BUILD-SNAPSHOT",
+				"name": "1.1.8 (SNAPSHOT)"
+			},
+			{
+				"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"
+	}
+}