Provide sensible defaults for launch script properties when using Gradle

Closes gh-4458

spring-boot-project/spring-boot-tools/spring-boot-gradle-plugin/src/main/java/org/springframework/boot/gradle/tasks/bundling/BootJar.java

@@ -184,7 +184,7 @@ public class BootJar extends Jar implements BootArchive {
 	private LaunchScriptConfiguration enableLaunchScriptIfNecessary() {
 		LaunchScriptConfiguration launchScript = this.support.getLaunchScript();
 		if (launchScript == null) {
-			launchScript = new LaunchScriptConfiguration();
+			launchScript = new LaunchScriptConfiguration(this);
 			this.support.setLaunchScript(launchScript);
 		}
 		return launchScript;

spring-boot-project/spring-boot-tools/spring-boot-gradle-plugin/src/main/java/org/springframework/boot/gradle/tasks/bundling/BootWar.java

@@ -162,7 +162,7 @@ public class BootWar extends War implements BootArchive {
 	private LaunchScriptConfiguration enableLaunchScriptIfNecessary() {
 		LaunchScriptConfiguration launchScript = this.support.getLaunchScript();
 		if (launchScript == null) {
-			launchScript = new LaunchScriptConfiguration();
+			launchScript = new LaunchScriptConfiguration(this);
 			this.support.setLaunchScript(launchScript);
 		}
 		return launchScript;

spring-boot-project/spring-boot-tools/spring-boot-gradle-plugin/src/main/java/org/springframework/boot/gradle/tasks/bundling/LaunchScriptConfiguration.java

@@ -22,6 +22,9 @@ import java.io.Serializable;
 import java.util.HashMap;
 import java.util.Map;
 
+import org.gradle.api.Project;
+import org.gradle.api.tasks.bundling.AbstractArchiveTask;
+
 import org.springframework.boot.loader.tools.FileUtils;
 
 /**
@@ -37,6 +40,19 @@ public class LaunchScriptConfiguration implements Serializable {
 
 	private File script;
 
+	public LaunchScriptConfiguration() {
+
+	}
+
+	LaunchScriptConfiguration(AbstractArchiveTask archiveTask) {
+		Project project = archiveTask.getProject();
+		putIfMissing(this.properties, "initInfoProvides", archiveTask.getBaseName());
+		putIfMissing(this.properties, "initInfoShortDescription",
+				removeLineBreaks(project.getDescription()), archiveTask.getBaseName());
+		putIfMissing(this.properties, "initInfoDescription",
+				augmentLineBreaks(project.getDescription()), archiveTask.getBaseName());
+	}
+
 	/**
 	 * Returns the properties that are applied to the launch script when it's being
 	 * including in the executable archive.
@@ -121,4 +137,24 @@ public class LaunchScriptConfiguration implements Serializable {
 		}
 	}
 
+	private String removeLineBreaks(String string) {
+		return (string != null ? string.replaceAll("\\s+", " ") : null);
+	}
+
+	private String augmentLineBreaks(String string) {
+		return (string != null ? string.replaceAll("\n", "\n#  ") : null);
+	}
+
+	private void putIfMissing(Map<String, String> properties, String key,
+			String... valueCandidates) {
+		if (!properties.containsKey(key)) {
+			for (String candidate : valueCandidates) {
+				if (candidate != null && !candidate.isEmpty()) {
+					properties.put(key, candidate);
+					return;
+				}
+			}
+		}
+	}
+
 }