Init command takes the output as last argument

This commit moves the --output switch to a regular argument. This aligns
to other command, i.e. spring init my-project.zip would save the project
to "my-project.zip" in the current directory.

This commit also auto-detects the --extract option if the location ends
with a slash, i.e. spring init demo/ would extract the content of the
project in a demo directory that is local to the current directory.

Fixes gh-1802

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

@@ -17,7 +17,9 @@
 package org.springframework.boot.cli.command.init;
 
 import java.io.IOException;
+import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.List;
 
 import joptsimple.OptionSet;
 import joptsimple.OptionSpec;
@@ -27,6 +29,7 @@ import org.springframework.boot.cli.command.OptionParsingCommand;
 import org.springframework.boot.cli.command.options.OptionHandler;
 import org.springframework.boot.cli.command.status.ExitStatus;
 import org.springframework.boot.cli.util.Log;
+import org.springframework.util.Assert;
 
 /**
  * {@link Command} that initializes a project using Spring initializr.
@@ -45,6 +48,11 @@ public class InitCommand extends OptionParsingCommand {
 				+ "Initialzr (start.spring.io)", handler);
 	}
 
+	@Override
+	public String getUsageHelp() {
+		return "[options] [location]";
+	}
+
 	static class InitOptionHandler extends OptionHandler {
 
 		private final ServiceCapabilitiesReportGenerator serviceCapabilitiesReport;
@@ -73,8 +81,6 @@ public class InitCommand extends OptionParsingCommand {
 
 		private OptionSpec<Void> force;
 
-		private OptionSpec<String> output;
-
 		InitOptionHandler(InitializrService initializrService) {
 			this.serviceCapabilitiesReport = new ServiceCapabilitiesReportGenerator(
 					initializrService);
@@ -123,14 +129,9 @@ public class InitCommand extends OptionParsingCommand {
 
 		private void otherOptions() {
 			this.extract = option(Arrays.asList("extract", "x"),
-					"Extract the project archive");
+					"Extract the project archive. Inferred if a location is specified and ends with /");
 			this.force = option(Arrays.asList("force", "f"),
 					"Force overwrite of existing files");
-			this.output = option(
-					Arrays.asList("output", "o"),
-					"Location of the generated project. Can be an absolute or a "
-							+ "relative reference and should refer to a directory when "
-							+ "--extract is used").withRequiredArg();
 		}
 
 		@Override
@@ -160,12 +161,17 @@ public class InitCommand extends OptionParsingCommand {
 
 		protected void generateProject(OptionSet options) throws IOException {
 			ProjectGenerationRequest request = createProjectGenerationRequest(options);
-			this.projectGenerator.generateProject(request, options.has(this.force),
-					options.has(this.extract), options.valueOf(this.output));
+			this.projectGenerator.generateProject(request, options.has(this.force));
 		}
 
 		protected ProjectGenerationRequest createProjectGenerationRequest(
 				OptionSet options) {
+
+			List<?> nonOptionArguments = new ArrayList<Object>(
+					options.nonOptionArguments());
+			Assert.isTrue(nonOptionArguments.size() <= 1,
+					"Only the target location may be specified");
+
 			ProjectGenerationRequest request = new ProjectGenerationRequest();
 			request.setServiceUrl(options.valueOf(this.target));
 			if (options.has(this.bootVersion)) {
@@ -188,8 +194,10 @@ public class InitCommand extends OptionParsingCommand {
 			if (options.has(this.type)) {
 				request.setType(options.valueOf(this.type));
 			}
-			if (options.has(this.output)) {
-				request.setOutput(options.valueOf(this.output));
+			request.setExtract(options.has(this.extract));
+			if (nonOptionArguments.size() == 1) {
+				String output = (String) nonOptionArguments.get(0);
+				request.setOutput(output);
 			}
 			return request;
 		}

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

@@ -40,6 +40,8 @@ class ProjectGenerationRequest {
 
 	private String output;
 
+	private boolean extract;
+
 	private String bootVersion;
 
 	private List<String> dependencies = new ArrayList<String>();
@@ -76,7 +78,25 @@ class ProjectGenerationRequest {
 	}
 
 	public void setOutput(String output) {
-		this.output = output;
+		if (output != null && output.endsWith("/")) {
+			this.output = output.substring(0, output.length() - 1);
+			this.extract = true;
+		} else {
+			this.output = output;
+		}
+	}
+
+	/**
+	 * Specify if the project archive should be extract in the output location. If
+	 * the {@link #getOutput() output} ends with "/", the project is extracted
+	 * automatically.
+	 */
+	public boolean isExtract() {
+		return extract;
+	}
+
+	public void setExtract(boolean extract) {
+		this.extract = extract;
 	}
 
 	/**

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

@@ -41,24 +41,23 @@ public class ProjectGenerator {
 		this.initializrService = initializrService;
 	}
 
-	public void generateProject(ProjectGenerationRequest request, boolean force,
-			boolean extract, String output) throws IOException {
+	public void generateProject(ProjectGenerationRequest request, boolean force) throws IOException {
 		ProjectGenerationResponse response = this.initializrService.generate(request);
-		if (extract) {
+		String fileName = (request.getOutput() != null ? request.getOutput() : response.getFileName());
+		if (request.isExtract()) {
 			if (isZipArchive(response)) {
-				extractProject(response, output, force);
+				extractProject(response, request.getOutput(), force);
 				return;
 			}
 			else {
 				Log.info("Could not extract '" + response.getContentType() + "'");
+				fileName = response.getFileName(); // Use value from the server since we can't extract it
 			}
 		}
-		String fileName = response.getFileName();
-		fileName = (fileName != null ? fileName : output);
 		if (fileName == null) {
 			throw new ReportableException(
 					"Could not save the project, the server did not set a preferred "
-							+ "file name. Use --output to specify the output location "
+							+ "file name and no location was set. Specify the output location "
 							+ "for the project.");
 		}
 		writeProject(response, fileName, force);
@@ -102,7 +101,7 @@ public class ProjectGenerator {
 				throw new ReportableException(file.isDirectory() ? "Directory" : "File"
 						+ " '" + file.getName()
 						+ "' already exists. Use --force if you want to overwrite or "
-						+ "--output to specify an alternate location.");
+						+ "specify an alternate location.");
 			}
 			if (!entry.isDirectory()) {
 				FileCopyUtils.copy(StreamUtils.nonClosing(zipStream),
@@ -123,7 +122,7 @@ public class ProjectGenerator {
 			if (!overwrite) {
 				throw new ReportableException("File '" + outputFile.getName()
 						+ "' already exists. Use --force if you want to "
-						+ "overwrite or --output to specify an alternate location.");
+						+ "overwrite or specify an alternate location.");
 			}
 			if (!outputFile.delete()) {
 				throw new ReportableException("Failed to delete existing file "