Code for BAEL-1812 (#4432)

* Thin jar option for Spring Boot bootstrap and gradle projects.

* .gitignore for spring-boot-gradle project.

* Maven and Gradle 'thin' Boot builds (optional)

* Rename 'wrapper' to 'thin' and shorten some lines of code to fit the article.

spring-boot-gradle/.gitignore

@@ -0,0 +1,2 @@
+.gradle/
+build/

spring-boot-gradle/build.gradle

@@ -1,12 +1,16 @@
 buildscript {
     ext {
-        springBootVersion = '2.0.0.RELEASE'
+        springBootPlugin = 'org.springframework.boot:spring-boot-gradle-plugin'
+        springBootVersion = '2.0.2.RELEASE'
+        thinPlugin = 'org.springframework.boot.experimental:spring-boot-thin-gradle-plugin'
+        thinVersion = '1.0.11.RELEASE'
     }
     repositories {
         mavenCentral()
     }
     dependencies {
-        classpath("org.springframework.boot:spring-boot-gradle-plugin:${springBootVersion}")
+        classpath("${springBootPlugin}:${springBootVersion}")
+        classpath("${thinPlugin}:${thinVersion}")
     }
 }
 
@@ -14,6 +18,8 @@ apply plugin: 'java'
 apply plugin: 'eclipse'
 apply plugin: 'org.springframework.boot'
 apply plugin: 'io.spring.dependency-management'
+//add tasks thinJar and thinResolve for thin JAR deployments
+apply plugin: 'org.springframework.boot.experimental.thin-launcher'
 
 group = 'org.baeldung'
 version = '0.0.1-SNAPSHOT'
@@ -23,7 +29,6 @@ repositories {
     mavenCentral()
 }
 
-
 dependencies {
     compile('org.springframework.boot:spring-boot-starter')
     testCompile('org.springframework.boot:spring-boot-starter-test')
@@ -42,3 +47,21 @@ bootJar {
 //        attributes 'Start-Class': 'org.baeldung.DemoApplication'
 //    }
 }
+
+//Enable this to generate and use a pom.xml file
+apply plugin: 'maven'
+
+//If you want to customize the generated pom.xml you can edit this task and add it as a dependency to the bootJar task
+task createPom {
+    def basePath = 'build/resources/main/META-INF/maven'
+    doLast {
+        pom {
+            withXml(dependencyManagement.pomConfigurer)
+        }.writeTo("${basePath}/${project.group}/${project.name}/pom.xml")
+    }
+}
+//Uncomment the following to use your custom generated pom.xml
+bootJar.dependsOn = [createPom]
+
+//Enable this to generate and use a thin.properties file
+//bootJar.dependsOn = [thinProperties]

spring-boot-gradle/gradle/wrapper/gradle-wrapper.properties

@@ -1,6 +1,6 @@
-#Tue Feb 06 12:27:20 CET 2018
+#Fri Jun 01 20:39:48 CEST 2018
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-4.5.1-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-4.5.1-all.zip