diff --git a/.settings-template.xml b/.settings-template.xml
index adf3aa28fa..fd16d48fcd 100644
--- a/.settings-template.xml
+++ b/.settings-template.xml
@@ -1,13 +1,13 @@
 <settings xmlns="http://maven.apache.org/SETTINGS/1.0.0"
 	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-	xsi:schemaLocation="http://maven.apache.org/SETTINGS/1.0.0 http://maven.apache.org/xsd/settings-1.0.0.xsd">
+	xsi:schemaLocation="http://maven.apache.org/SETTINGS/1.0.0 https://maven.apache.org/xsd/settings-1.0.0.xsd">
 	<profiles>
 		<profile>
 			<id>snapshot</id>
 			<repositories>
 				<repository>
 					<id>spring-ext</id>
-					<url>http://repo.spring.io/ext-release-local/</url>
+					<url>https://repo.spring.io/ext-release-local/</url>
 					<releases>
 						<enabled>true</enabled>
 					</releases>
@@ -18,7 +18,7 @@
 				<repository>
 					<id>spring-milestones</id>
 					<name>Spring Milestones</name>
-					<url>http://repo.spring.io/milestone</url>
+					<url>https://repo.spring.io/milestone</url>
 					<snapshots>
 						<enabled>false</enabled>
 					</snapshots>
@@ -26,7 +26,7 @@
 				<repository>
 					<id>spring-snapshots</id>
 					<name>Spring Snapshots</name>
-					<url>http://repo.spring.io/snapshot</url>
+					<url>https://repo.spring.io/snapshot</url>
 					<snapshots>
 						<enabled>true</enabled>
 					</snapshots>
@@ -46,7 +46,7 @@
 				<pluginRepository>
 					<id>spring-milestones</id>
 					<name>Spring Milestones</name>
-					<url>http://repo.spring.io/milestone</url>
+					<url>https://repo.spring.io/milestone</url>
 					<snapshots>
 						<enabled>false</enabled>
 					</snapshots>
@@ -54,7 +54,7 @@
 				<pluginRepository>
 					<id>spring-snapshots</id>
 					<name>Spring Snapshots</name>
-					<url>http://repo.spring.io/snapshot</url>
+					<url>https://repo.spring.io/snapshot</url>
 					<snapshots>
 						<enabled>true</enabled>
 					</snapshots>
@@ -66,7 +66,7 @@
 			<repositories>
 				<repository>
 					<id>spring-ext</id>
-					<url>http://repo.spring.io/ext-release-local/</url>
+					<url>https://repo.spring.io/ext-release-local/</url>
 					<releases>
 						<enabled>true</enabled>
 					</releases>
@@ -87,7 +87,7 @@
 				<repository>
 					<id>spring-milestones</id>
 					<name>Spring Milestones</name>
-					<url>http://repo.spring.io/milestone</url>
+					<url>https://repo.spring.io/milestone</url>
 					<snapshots>
 						<enabled>false</enabled>
 					</snapshots>
@@ -97,7 +97,7 @@
 				<pluginRepository>
 					<id>spring-milestones</id>
 					<name>Spring Milestones</name>
-					<url>http://repo.spring.io/snapshot</url>
+					<url>https://repo.spring.io/snapshot</url>
 					<snapshots>
 						<enabled>false</enabled>
 					</snapshots>
@@ -109,7 +109,7 @@
 			<repositories>
 				<repository>
 					<id>spring-ext</id>
-					<url>http://repo.spring.io/ext-release-local/</url>
+					<url>https://repo.spring.io/ext-release-local/</url>
 					<releases>
 						<enabled>true</enabled>
 					</releases>
diff --git a/spring-boot-autoconfigure/src/test/resources/META-INF/persistence.xml b/spring-boot-autoconfigure/src/test/resources/META-INF/persistence.xml
index 1607abfb57..439d601d8f 100644
--- a/spring-boot-autoconfigure/src/test/resources/META-INF/persistence.xml
+++ b/spring-boot-autoconfigure/src/test/resources/META-INF/persistence.xml
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<persistence version="2.0" xmlns="http://java.sun.com/xml/ns/persistence" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_2_0.xsd">
+<persistence version="2.0" xmlns="http://java.sun.com/xml/ns/persistence" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/persistence https://java.sun.com/xml/ns/persistence/persistence_2_0.xsd">
 	<persistence-unit name="manually-configured">
 		<class>org.springframework.boot.autoconfigure.orm.jpa.test.City</class>
 		<exclude-unlisted-classes>true</exclude-unlisted-classes>
diff --git a/spring-boot-autoconfigure/src/test/resources/db/changelog/db.changelog-override.xml b/spring-boot-autoconfigure/src/test/resources/db/changelog/db.changelog-override.xml
index 2e418cb347..52c3ccfe5d 100644
--- a/spring-boot-autoconfigure/src/test/resources/db/changelog/db.changelog-override.xml
+++ b/spring-boot-autoconfigure/src/test/resources/db/changelog/db.changelog-override.xml
@@ -3,8 +3,8 @@
         xmlns="http://www.liquibase.org/xml/ns/dbchangelog"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xmlns:ext="http://www.liquibase.org/xml/ns/dbchangelog-ext"
-        xsi:schemaLocation="http://www.liquibase.org/xml/ns/dbchangelog http://www.liquibase.org/xml/ns/dbchangelog/dbchangelog-3.0.xsd
-        http://www.liquibase.org/xml/ns/dbchangelog-ext http://www.liquibase.org/xml/ns/dbchangelog/dbchangelog-ext.xsd">
+        xsi:schemaLocation="http://www.liquibase.org/xml/ns/dbchangelog https://www.liquibase.org/xml/ns/dbchangelog/dbchangelog-3.0.xsd
+        http://www.liquibase.org/xml/ns/dbchangelog-ext https://www.liquibase.org/xml/ns/dbchangelog/dbchangelog-ext.xsd">
 
     <changeSet id="1" author="marceloverdijk">
         <createTable tableName="customer">
diff --git a/spring-boot-autoconfigure/src/test/resources/early-init-test.xml b/spring-boot-autoconfigure/src/test/resources/early-init-test.xml
index 9c28c45026..2ef5e73d12 100644
--- a/spring-boot-autoconfigure/src/test/resources/early-init-test.xml
+++ b/spring-boot-autoconfigure/src/test/resources/early-init-test.xml
@@ -2,7 +2,7 @@
 
 <beans xmlns="http://www.springframework.org/schema/beans"
 	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-	xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd">
+	xsi:schemaLocation="http://www.springframework.org/schema/beans https://www.springframework.org/schema/beans/spring-beans.xsd">
 
 	<bean id="earlyInit" class="org.springframework.boot.autoconfigure.EarlyInitFactoryBean" >
 		<property name="propertyFromConfig" value="${foo}" />
diff --git a/spring-boot-autoconfigure/src/test/resources/infinispan.xml b/spring-boot-autoconfigure/src/test/resources/infinispan.xml
index 88d844365e..88b28daa6e 100644
--- a/spring-boot-autoconfigure/src/test/resources/infinispan.xml
+++ b/spring-boot-autoconfigure/src/test/resources/infinispan.xml
@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <infinispan xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-            xsi:schemaLocation="urn:infinispan:config:7.1 http://www.infinispan.org/schemas/infinispan-config-7.1.xsd"
+            xsi:schemaLocation="urn:infinispan:config:7.1 https://infinispan.org/schemas/infinispan-config-7.1.xsd"
             xmlns="urn:infinispan:config:7.1">
 
 	<!-- ************************************** -->
diff --git a/spring-boot-autoconfigure/src/test/resources/org/springframework/boot/autoconfigure/condition/factorybean.xml b/spring-boot-autoconfigure/src/test/resources/org/springframework/boot/autoconfigure/condition/factorybean.xml
index bac59ef4f0..a7852de0c2 100644
--- a/spring-boot-autoconfigure/src/test/resources/org/springframework/boot/autoconfigure/condition/factorybean.xml
+++ b/spring-boot-autoconfigure/src/test/resources/org/springframework/boot/autoconfigure/condition/factorybean.xml
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <beans xmlns="http://www.springframework.org/schema/beans"
 	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-	xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd">
+	xsi:schemaLocation="http://www.springframework.org/schema/beans https://www.springframework.org/schema/beans/spring-beans.xsd">
 
 	<bean id="example"
 		class="org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBeanTests.ExampleFactoryBean">
diff --git a/spring-boot-autoconfigure/src/test/resources/org/springframework/boot/autoconfigure/condition/foo.xml b/spring-boot-autoconfigure/src/test/resources/org/springframework/boot/autoconfigure/condition/foo.xml
index 735b571fc7..80a64071da 100644
--- a/spring-boot-autoconfigure/src/test/resources/org/springframework/boot/autoconfigure/condition/foo.xml
+++ b/spring-boot-autoconfigure/src/test/resources/org/springframework/boot/autoconfigure/condition/foo.xml
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <beans xmlns="http://www.springframework.org/schema/beans"
 	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-	xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd">
+	xsi:schemaLocation="http://www.springframework.org/schema/beans https://www.springframework.org/schema/beans/spring-beans.xsd">
 
 	<bean id="foo" class="java.lang.String">
 		<constructor-arg value="foo" />
diff --git a/spring-boot-cli/samples/runner.xml b/spring-boot-cli/samples/runner.xml
index 2a8f5aad1a..ac4fb0599e 100644
--- a/spring-boot-cli/samples/runner.xml
+++ b/spring-boot-cli/samples/runner.xml
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <beans xmlns="http://www.springframework.org/schema/beans"
 	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-	xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd">
+	xsi:schemaLocation="http://www.springframework.org/schema/beans https://www.springframework.org/schema/beans/spring-beans.xsd">
 
 	<bean id="runner" class="org.test.Runner"/>
 
diff --git a/spring-boot-cli/src/main/assembly/jar-with-dependencies.xml b/spring-boot-cli/src/main/assembly/jar-with-dependencies.xml
index a6b4733911..4a4dcdfc69 100644
--- a/spring-boot-cli/src/main/assembly/jar-with-dependencies.xml
+++ b/spring-boot-cli/src/main/assembly/jar-with-dependencies.xml
@@ -2,7 +2,7 @@
 <assembly
 	xmlns="http://maven.apache.org/plugins/maven-assembly-plugin/assembly/1.1.2"
 	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-	xsi:schemaLocation="http://maven.apache.org/plugins/maven-assembly-plugin/assembly/1.1.2 http://maven.apache.org/xsd/assembly-1.1.2.xsd">
+	xsi:schemaLocation="http://maven.apache.org/plugins/maven-assembly-plugin/assembly/1.1.2 https://maven.apache.org/xsd/assembly-1.1.2.xsd">
 	<id>full</id>
 	<formats>
 		<format>jar</format>
diff --git a/spring-boot-cli/src/test/resources/.m2/settings.xml b/spring-boot-cli/src/test/resources/.m2/settings.xml
index 86a68acfac..6cc8d41bd2 100644
--- a/spring-boot-cli/src/test/resources/.m2/settings.xml
+++ b/spring-boot-cli/src/test/resources/.m2/settings.xml
@@ -1,12 +1,12 @@
 <settings xmlns="http://maven.apache.org/SETTINGS/1.0.0"
 	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 	xsi:schemaLocation="http://maven.apache.org/SETTINGS/1.0.0
-		http://maven.apache.org/xsd/settings-1.0.0.xsd">
+		https://maven.apache.org/xsd/settings-1.0.0.xsd">
 
 	<mirrors>
 		<mirror>
 			<id>central-mirror</id>
-			<url>http://central-mirror.example.com/maven2</url>
+			<url>https://central-mirror.example.com/maven2</url>
 			<mirrorOf>central</mirrorOf>
 		</mirror>
 	</mirrors>
diff --git a/spring-boot-cli/src/test/resources/maven-settings/active-profile-repositories/.m2/settings.xml b/spring-boot-cli/src/test/resources/maven-settings/active-profile-repositories/.m2/settings.xml
index 8cc312378d..a4bba4bb57 100644
--- a/spring-boot-cli/src/test/resources/maven-settings/active-profile-repositories/.m2/settings.xml
+++ b/spring-boot-cli/src/test/resources/maven-settings/active-profile-repositories/.m2/settings.xml
@@ -3,7 +3,7 @@
 	<mirrors>
 		<mirror>
 			<id>my-mirror</id>
-			<url>http://maven.example.com/mirror</url>
+			<url>https://maven.example.com/mirror</url>
 			<mirrorOf>my-server</mirrorOf>
 		</mirror>
 	</mirrors>
diff --git a/spring-boot-cli/src/test/resources/maven-settings/basic/.m2/settings.xml b/spring-boot-cli/src/test/resources/maven-settings/basic/.m2/settings.xml
index 5439ce8cfb..b9e5be086d 100644
--- a/spring-boot-cli/src/test/resources/maven-settings/basic/.m2/settings.xml
+++ b/spring-boot-cli/src/test/resources/maven-settings/basic/.m2/settings.xml
@@ -3,7 +3,7 @@
 	<mirrors>
 		<mirror>
 			<id>my-mirror</id>
-			<url>http://maven.example.com/mirror</url>
+			<url>https://maven.example.com/mirror</url>
 			<mirrorOf>my-server</mirrorOf>
 		</mirror>
 	</mirrors>
@@ -39,7 +39,7 @@
 	    	<repositories>
 	        	<repository>
 	            	<id>example-repository</id>
-	            	<url>http://repo.example.com</url>
+	            	<url>https://repo.example.com</url>
 	        	</repository>
 	    	</repositories>
 		</profile>
diff --git a/spring-boot-cli/src/test/resources/maven-settings/encrypted/.m2/settings.xml b/spring-boot-cli/src/test/resources/maven-settings/encrypted/.m2/settings.xml
index b8701c783a..5160df5657 100644
--- a/spring-boot-cli/src/test/resources/maven-settings/encrypted/.m2/settings.xml
+++ b/spring-boot-cli/src/test/resources/maven-settings/encrypted/.m2/settings.xml
@@ -3,7 +3,7 @@
 	<mirrors>
 		<mirror>
 			<id>my-mirror</id>
-			<url>http://maven.example.com/mirror</url>
+			<url>https://maven.example.com/mirror</url>
 			<mirrorOf>my-server</mirrorOf>
 		</mirror>
 	</mirrors>
diff --git a/spring-boot-cli/src/test/resources/maven-settings/property-interpolation/.m2/settings.xml b/spring-boot-cli/src/test/resources/maven-settings/property-interpolation/.m2/settings.xml
index 873642e6dd..a70af0b4c8 100644
--- a/spring-boot-cli/src/test/resources/maven-settings/property-interpolation/.m2/settings.xml
+++ b/spring-boot-cli/src/test/resources/maven-settings/property-interpolation/.m2/settings.xml
@@ -1,7 +1,7 @@
 <settings xmlns="http://maven.apache.org/SETTINGS/1.0.0"
 	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 	xsi:schemaLocation="http://maven.apache.org/SETTINGS/1.0.0
-		http://maven.apache.org/xsd/settings-1.0.0.xsd">
+		https://maven.apache.org/xsd/settings-1.0.0.xsd">
 
 	<localRepository>${foo}/repository</localRepository>
 
diff --git a/spring-boot-docs/src/main/docbook/xsl/xslthl-config.xml b/spring-boot-docs/src/main/docbook/xsl/xslthl-config.xml
index e4d677fc50..e354da15f1 100644
--- a/spring-boot-docs/src/main/docbook/xsl/xslthl-config.xml
+++ b/spring-boot-docs/src/main/docbook/xsl/xslthl-config.xml
@@ -19,5 +19,5 @@
 	<highlighter id="properties" file="./xslthl/properties-hl.xml" />
 	<highlighter id="json" file="./xslthl/json-hl.xml" />
 	<highlighter id="yaml" file="./xslthl/yaml-hl.xml" />
-	<namespace prefix="xslthl" uri="http://xslthl.sf.net" />
+	<namespace prefix="xslthl" uri="http://xslthl.sourceforge.net/" />
 </xslthl-config>
diff --git a/spring-boot-docs/src/main/docbook/xsl/xslthl/bourne-hl.xml b/spring-boot-docs/src/main/docbook/xsl/xslthl/bourne-hl.xml
index e2cd98d8b5..90408acc6e 100644
--- a/spring-boot-docs/src/main/docbook/xsl/xslthl/bourne-hl.xml
+++ b/spring-boot-docs/src/main/docbook/xsl/xslthl/bourne-hl.xml
@@ -4,7 +4,7 @@
 Syntax highlighting definition for SH
 
 xslthl - XSLT Syntax Highlighting
-http://sourceforge.net/projects/xslthl/
+https://sourceforge.net/projects/xslthl/
 Copyright (C) 2010 Mathieu Malaterre
 
 This software is provided 'as-is', without any express or implied
diff --git a/spring-boot-docs/src/main/docbook/xsl/xslthl/c-hl.xml b/spring-boot-docs/src/main/docbook/xsl/xslthl/c-hl.xml
index 176cc379ff..7363dba911 100644
--- a/spring-boot-docs/src/main/docbook/xsl/xslthl/c-hl.xml
+++ b/spring-boot-docs/src/main/docbook/xsl/xslthl/c-hl.xml
@@ -3,7 +3,7 @@
 Syntax highlighting definition for C
 
 xslthl - XSLT Syntax Highlighting
-http://sourceforge.net/projects/xslthl/
+https://sourceforge.net/projects/xslthl/
 Copyright (C) 2005-2008 Michal Molhanec, Jirka Kosek, Michiel Hendriks
 
 This software is provided 'as-is', without any express or implied
diff --git a/spring-boot-docs/src/main/docbook/xsl/xslthl/cpp-hl.xml b/spring-boot-docs/src/main/docbook/xsl/xslthl/cpp-hl.xml
index ef83c4f5ee..b31f736221 100644
--- a/spring-boot-docs/src/main/docbook/xsl/xslthl/cpp-hl.xml
+++ b/spring-boot-docs/src/main/docbook/xsl/xslthl/cpp-hl.xml
@@ -4,7 +4,7 @@
 Syntax highlighting definition for C++
 
 xslthl - XSLT Syntax Highlighting
-http://sourceforge.net/projects/xslthl/
+https://sourceforge.net/projects/xslthl/
 Copyright (C) 2005-2008 Michal Molhanec, Jirka Kosek, Michiel Hendriks
 
 This software is provided 'as-is', without any express or implied
diff --git a/spring-boot-docs/src/main/docbook/xsl/xslthl/csharp-hl.xml b/spring-boot-docs/src/main/docbook/xsl/xslthl/csharp-hl.xml
index d57e631029..09373348a5 100644
--- a/spring-boot-docs/src/main/docbook/xsl/xslthl/csharp-hl.xml
+++ b/spring-boot-docs/src/main/docbook/xsl/xslthl/csharp-hl.xml
@@ -4,7 +4,7 @@
 Syntax highlighting definition for C#
 
 xslthl - XSLT Syntax Highlighting
-http://sourceforge.net/projects/xslthl/
+https://sourceforge.net/projects/xslthl/
 Copyright (C) 2005-2008 Michal Molhanec, Jirka Kosek, Michiel Hendriks
 
 This software is provided 'as-is', without any express or implied
diff --git a/spring-boot-docs/src/main/docbook/xsl/xslthl/css-hl.xml b/spring-boot-docs/src/main/docbook/xsl/xslthl/css-hl.xml
index 164c48c3d8..21439ae69d 100644
--- a/spring-boot-docs/src/main/docbook/xsl/xslthl/css-hl.xml
+++ b/spring-boot-docs/src/main/docbook/xsl/xslthl/css-hl.xml
@@ -4,7 +4,7 @@
 Syntax highlighting definition for CSS files
 
 xslthl - XSLT Syntax Highlighting
-http://sourceforge.net/projects/xslthl/
+https://sourceforge.net/projects/xslthl/
 Copyright (C) 2011-2012 Martin Hujer, Michiel Hendriks
 
 This software is provided 'as-is', without any express or implied
@@ -26,7 +26,7 @@ freely, subject to the following restrictions:
 Martin Hujer <mhujer at users.sourceforge.net>
 Michiel Hendriks <elmuerte at users.sourceforge.net>
 
-Reference: http://www.w3.org/TR/CSS21/propidx.html
+Reference: https://www.w3.org/TR/CSS21/propidx.html
 
 -->
 <highlighters>
diff --git a/spring-boot-docs/src/main/docbook/xsl/xslthl/html-hl.xml b/spring-boot-docs/src/main/docbook/xsl/xslthl/html-hl.xml
index 5b6761bab9..366cd46f22 100644
--- a/spring-boot-docs/src/main/docbook/xsl/xslthl/html-hl.xml
+++ b/spring-boot-docs/src/main/docbook/xsl/xslthl/html-hl.xml
@@ -7,7 +7,7 @@
   myxml-hl.xml - konfigurace zvyraznovace XML, ktera zvlast zvyrazni
                  HTML elementy a XSL elementy
 
-  This file has been customized for the Asciidoctor project (http://asciidoctor.org).
+  This file has been customized for the Asciidoctor project (https://asciidoctor.org).
 -->
 <highlighters>
   <highlighter type="xml">
diff --git a/spring-boot-docs/src/main/docbook/xsl/xslthl/ini-hl.xml b/spring-boot-docs/src/main/docbook/xsl/xslthl/ini-hl.xml
index 34c103637e..6bd60b3e30 100644
--- a/spring-boot-docs/src/main/docbook/xsl/xslthl/ini-hl.xml
+++ b/spring-boot-docs/src/main/docbook/xsl/xslthl/ini-hl.xml
@@ -4,7 +4,7 @@
 Syntax highlighting definition for ini files
 
 xslthl - XSLT Syntax Highlighting
-http://sourceforge.net/projects/xslthl/
+https://sourceforge.net/projects/xslthl/
 Copyright (C) 2005-2008 Michal Molhanec, Jirka Kosek, Michiel Hendriks
 
 This software is provided 'as-is', without any express or implied
diff --git a/spring-boot-docs/src/main/docbook/xsl/xslthl/java-hl.xml b/spring-boot-docs/src/main/docbook/xsl/xslthl/java-hl.xml
index f7bb164146..4fe3c1fecc 100644
--- a/spring-boot-docs/src/main/docbook/xsl/xslthl/java-hl.xml
+++ b/spring-boot-docs/src/main/docbook/xsl/xslthl/java-hl.xml
@@ -4,7 +4,7 @@
 Syntax highlighting definition for Java
 
 xslthl - XSLT Syntax Highlighting
-http://sourceforge.net/projects/xslthl/
+https://sourceforge.net/projects/xslthl/
 Copyright (C) 2005-2008 Michal Molhanec, Jirka Kosek, Michiel Hendriks
 
 This software is provided 'as-is', without any express or implied
diff --git a/spring-boot-docs/src/main/docbook/xsl/xslthl/javascript-hl.xml b/spring-boot-docs/src/main/docbook/xsl/xslthl/javascript-hl.xml
index 99b8a71e96..91620401fc 100644
--- a/spring-boot-docs/src/main/docbook/xsl/xslthl/javascript-hl.xml
+++ b/spring-boot-docs/src/main/docbook/xsl/xslthl/javascript-hl.xml
@@ -4,7 +4,7 @@
 Syntax highlighting definition for JavaScript
 
 xslthl - XSLT Syntax Highlighting
-http://sourceforge.net/projects/xslthl/
+https://sourceforge.net/projects/xslthl/
 Copyright (C) 2005-2008 Michal Molhanec, Jirka Kosek, Michiel Hendriks
 
 This software is provided 'as-is', without any express or implied
diff --git a/spring-boot-docs/src/main/docbook/xsl/xslthl/perl-hl.xml b/spring-boot-docs/src/main/docbook/xsl/xslthl/perl-hl.xml
index 73d71cc02c..c8a4d5902a 100644
--- a/spring-boot-docs/src/main/docbook/xsl/xslthl/perl-hl.xml
+++ b/spring-boot-docs/src/main/docbook/xsl/xslthl/perl-hl.xml
@@ -4,7 +4,7 @@
 Syntax highlighting definition for Perl
 
 xslthl - XSLT Syntax Highlighting
-http://sourceforge.net/projects/xslthl/
+https://sourceforge.net/projects/xslthl/
 Copyright (C) 2005-2008 Michal Molhanec, Jirka Kosek, Michiel Hendriks
 
 This software is provided 'as-is', without any express or implied
diff --git a/spring-boot-docs/src/main/docbook/xsl/xslthl/php-hl.xml b/spring-boot-docs/src/main/docbook/xsl/xslthl/php-hl.xml
index 1da25b8cc6..3ea157873b 100644
--- a/spring-boot-docs/src/main/docbook/xsl/xslthl/php-hl.xml
+++ b/spring-boot-docs/src/main/docbook/xsl/xslthl/php-hl.xml
@@ -4,7 +4,7 @@
 Syntax highlighting definition for PHP
 
 xslthl - XSLT Syntax Highlighting
-http://sourceforge.net/projects/xslthl/
+https://sourceforge.net/projects/xslthl/
 Copyright (C) 2005-2008 Michal Molhanec, Jirka Kosek, Michiel Hendriks
 
 This software is provided 'as-is', without any express or implied
diff --git a/spring-boot-docs/src/main/docbook/xsl/xslthl/properties-hl.xml b/spring-boot-docs/src/main/docbook/xsl/xslthl/properties-hl.xml
index 775f2f13e7..8205aac323 100644
--- a/spring-boot-docs/src/main/docbook/xsl/xslthl/properties-hl.xml
+++ b/spring-boot-docs/src/main/docbook/xsl/xslthl/properties-hl.xml
@@ -4,7 +4,7 @@
 Syntax highlighting definition for Java
 
 xslthl - XSLT Syntax Highlighting
-http://sourceforge.net/projects/xslthl/
+https://sourceforge.net/projects/xslthl/
 Copyright (C) 2005-2008 Michal Molhanec, Jirka Kosek, Michiel Hendriks
 
 This software is provided 'as-is', without any express or implied
diff --git a/spring-boot-docs/src/main/docbook/xsl/xslthl/python-hl.xml b/spring-boot-docs/src/main/docbook/xsl/xslthl/python-hl.xml
index a467443239..72bf0dbb1f 100644
--- a/spring-boot-docs/src/main/docbook/xsl/xslthl/python-hl.xml
+++ b/spring-boot-docs/src/main/docbook/xsl/xslthl/python-hl.xml
@@ -4,7 +4,7 @@
 Syntax highlighting definition for Python
 
 xslthl - XSLT Syntax Highlighting
-http://sourceforge.net/projects/xslthl/
+https://sourceforge.net/projects/xslthl/
 Copyright (C) 2005-2008 Michal Molhanec, Jirka Kosek, Michiel Hendriks
 
 This software is provided 'as-is', without any express or implied
diff --git a/spring-boot-docs/src/main/docbook/xsl/xslthl/ruby-hl.xml b/spring-boot-docs/src/main/docbook/xsl/xslthl/ruby-hl.xml
index d105640e80..a2cee724aa 100644
--- a/spring-boot-docs/src/main/docbook/xsl/xslthl/ruby-hl.xml
+++ b/spring-boot-docs/src/main/docbook/xsl/xslthl/ruby-hl.xml
@@ -4,7 +4,7 @@
 Syntax highlighting definition for Ruby
 
 xslthl - XSLT Syntax Highlighting
-http://sourceforge.net/projects/xslthl/
+https://sourceforge.net/projects/xslthl/
 Copyright (C) 2005-2008 Michal Molhanec, Jirka Kosek, Michiel Hendriks
 
 This software is provided 'as-is', without any express or implied
diff --git a/spring-boot-docs/src/main/docbook/xsl/xslthl/sql2003-hl.xml b/spring-boot-docs/src/main/docbook/xsl/xslthl/sql2003-hl.xml
index ac1d5d048b..65c08a3698 100644
--- a/spring-boot-docs/src/main/docbook/xsl/xslthl/sql2003-hl.xml
+++ b/spring-boot-docs/src/main/docbook/xsl/xslthl/sql2003-hl.xml
@@ -4,7 +4,7 @@
 Syntax highlighting definition for SQL:1999
 
 xslthl - XSLT Syntax Highlighting
-http://sourceforge.net/projects/xslthl/
+https://sourceforge.net/projects/xslthl/
 Copyright (C) 2012 Michiel Hendriks, Martin Hujer, k42b3
 
 This software is provided 'as-is', without any express or implied
diff --git a/spring-boot-parent/src/checkstyle/checkstyle-suppressions.xml b/spring-boot-parent/src/checkstyle/checkstyle-suppressions.xml
index df411c7057..29d4e0e942 100644
--- a/spring-boot-parent/src/checkstyle/checkstyle-suppressions.xml
+++ b/spring-boot-parent/src/checkstyle/checkstyle-suppressions.xml
@@ -1,7 +1,7 @@
 <?xml version="1.0"?>
 <!DOCTYPE suppressions PUBLIC
-    "-//Puppy Crawl//DTD Suppressions 1.1//EN"
-    "http://www.puppycrawl.com/dtds/suppressions_1_1.dtd">
+    "-//Checkstyle//DTD SuppressionFilter Configuration 1.2//EN"
+    "https://checkstyle.org/dtds/suppressions_1_2.dtd">
 <suppressions>
 	<suppress files="SpringApplicationTests\.java" checks="FinalClass" />
 	<suppress files=".+Configuration\.java" checks="HideUtilityClassConstructor" />
diff --git a/spring-boot-parent/src/checkstyle/checkstyle.xml b/spring-boot-parent/src/checkstyle/checkstyle.xml
index 8bb9e0a83a..7aa0dddfe3 100644
--- a/spring-boot-parent/src/checkstyle/checkstyle.xml
+++ b/spring-boot-parent/src/checkstyle/checkstyle.xml
@@ -1,5 +1,5 @@
 <?xml version="1.0"?>
-<!DOCTYPE module PUBLIC "-//Puppy Crawl//DTD Check Configuration 1.2//EN" "http://www.puppycrawl.com/dtds/configuration_1_2.dtd">
+<!DOCTYPE module PUBLIC "-//Puppy Crawl//DTD Check Configuration 1.2//EN" "https://checkstyle.org/dtds/configuration_1_2.dtd">
 <module name="com.puppycrawl.tools.checkstyle.Checker">
 	<!-- Root Checks -->
 	<module name="com.puppycrawl.tools.checkstyle.checks.header.RegexpHeaderCheck">
diff --git a/spring-boot-samples/spring-boot-sample-ant/ivysettings.xml b/spring-boot-samples/spring-boot-sample-ant/ivysettings.xml
index 4127a506e8..e2e5a05f73 100644
--- a/spring-boot-samples/spring-boot-sample-ant/ivysettings.xml
+++ b/spring-boot-samples/spring-boot-sample-ant/ivysettings.xml
@@ -8,9 +8,9 @@
 				<ivy pattern="${user.home}/.m2/repository/[organisation]/[module]/[revision]/[module]-[revision].pom" />
 			</filesystem>
 			<ibiblio name="ibiblio" m2compatible="true" />
-			<ibiblio name="spring-milestones" m2compatible="true" root="http://repo.spring.io/release" />
-			<ibiblio name="spring-milestones" m2compatible="true" root="http://repo.spring.io/milestone" />
-			<ibiblio name="spring-snapshots" m2compatible="true" root="http://repo.spring.io/snapshot" />
+			<ibiblio name="spring-milestones" m2compatible="true" root="https://repo.spring.io/release" />
+			<ibiblio name="spring-milestones" m2compatible="true" root="https://repo.spring.io/milestone" />
+			<ibiblio name="spring-snapshots" m2compatible="true" root="https://repo.spring.io/snapshot" />
 		</chain>
 	</resolvers>
 </ivysettings>
diff --git a/spring-boot-samples/spring-boot-sample-traditional/src/main/webapp/WEB-INF/web.xml b/spring-boot-samples/spring-boot-sample-traditional/src/main/webapp/WEB-INF/web.xml
index b7db240932..6fc387aeaf 100644
--- a/spring-boot-samples/spring-boot-sample-traditional/src/main/webapp/WEB-INF/web.xml
+++ b/spring-boot-samples/spring-boot-sample-traditional/src/main/webapp/WEB-INF/web.xml
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <web-app version="2.5" xmlns="http://java.sun.com/xml/ns/javaee"
 	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-	xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">
+	xsi:schemaLocation="http://java.sun.com/xml/ns/javaee https://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">
 
 	<servlet>
 		<servlet-name>appServlet</servlet-name>
diff --git a/spring-boot-samples/spring-boot-sample-xml/src/main/resources/META-INF/application-context.xml b/spring-boot-samples/spring-boot-sample-xml/src/main/resources/META-INF/application-context.xml
index dcc6e4b20b..f080646aa1 100644
--- a/spring-boot-samples/spring-boot-sample-xml/src/main/resources/META-INF/application-context.xml
+++ b/spring-boot-samples/spring-boot-sample-xml/src/main/resources/META-INF/application-context.xml
@@ -2,8 +2,8 @@
 <beans xmlns="http://www.springframework.org/schema/beans"
 	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 	xmlns:context="http://www.springframework.org/schema/context"
-	xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
-				http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd">
+	xsi:schemaLocation="http://www.springframework.org/schema/beans https://www.springframework.org/schema/beans/spring-beans.xsd
+				http://www.springframework.org/schema/context https://www.springframework.org/schema/context/spring-context.xsd">
 
 	<context:annotation-config/>
 	<context:property-placeholder/>
diff --git a/spring-boot-test/src/test/resources/org/springframework/boot/test/SpringApplicationConfigurationXmlConventionConfigurationTests-context.xml b/spring-boot-test/src/test/resources/org/springframework/boot/test/SpringApplicationConfigurationXmlConventionConfigurationTests-context.xml
index a25ca5b996..a231d42152 100644
--- a/spring-boot-test/src/test/resources/org/springframework/boot/test/SpringApplicationConfigurationXmlConventionConfigurationTests-context.xml
+++ b/spring-boot-test/src/test/resources/org/springframework/boot/test/SpringApplicationConfigurationXmlConventionConfigurationTests-context.xml
@@ -1,8 +1,8 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <beans xmlns="http://www.springframework.org/schema/beans"
 	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context"
-	xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
-				http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd">
+	xsi:schemaLocation="http://www.springframework.org/schema/beans https://www.springframework.org/schema/beans/spring-beans.xsd
+				http://www.springframework.org/schema/context https://www.springframework.org/schema/context/spring-context.xsd">
 
 	<bean id="foo" class="java.lang.String">
 		<constructor-arg>
diff --git a/spring-boot-tools/spring-boot-antlib/src/it/sample/ivysettings.xml b/spring-boot-tools/spring-boot-antlib/src/it/sample/ivysettings.xml
index 72631b8ba8..7db494eea2 100644
--- a/spring-boot-tools/spring-boot-antlib/src/it/sample/ivysettings.xml
+++ b/spring-boot-tools/spring-boot-antlib/src/it/sample/ivysettings.xml
@@ -8,9 +8,9 @@
 				<ivy pattern="${user.home}/.m2/[organisation]/[module]/[revision]/[module]-[revision].pom" />
 			</filesystem>
 			<ibiblio name="ibiblio" m2compatible="true" />
-			<ibiblio name="spring-milestones" m2compatible="true" root="http://repo.spring.io/release" />
-			<ibiblio name="spring-milestones" m2compatible="true" root="http://repo.spring.io/milestone" />
-			<ibiblio name="spring-snapshots" m2compatible="true" root="http://repo.spring.io/snapshot" />
+			<ibiblio name="spring-milestones" m2compatible="true" root="https://repo.spring.io/release" />
+			<ibiblio name="spring-milestones" m2compatible="true" root="https://repo.spring.io/milestone" />
+			<ibiblio name="spring-snapshots" m2compatible="true" root="https://repo.spring.io/snapshot" />
 		</chain>
 	</resolvers>
 </ivysettings>
diff --git a/spring-boot-tools/spring-boot-loader/src/it/executable-jar/src/main/assembly/jar-with-dependencies.xml b/spring-boot-tools/spring-boot-loader/src/it/executable-jar/src/main/assembly/jar-with-dependencies.xml
index 44626f91aa..1f7cf8ec13 100644
--- a/spring-boot-tools/spring-boot-loader/src/it/executable-jar/src/main/assembly/jar-with-dependencies.xml
+++ b/spring-boot-tools/spring-boot-loader/src/it/executable-jar/src/main/assembly/jar-with-dependencies.xml
@@ -2,7 +2,7 @@
 <assembly
 	xmlns="http://maven.apache.org/plugins/maven-assembly-plugin/assembly/1.1.2"
 	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-	xsi:schemaLocation="http://maven.apache.org/plugins/maven-assembly-plugin/assembly/1.1.2 http://maven.apache.org/xsd/assembly-1.1.2.xsd">
+	xsi:schemaLocation="http://maven.apache.org/plugins/maven-assembly-plugin/assembly/1.1.2 https://maven.apache.org/xsd/assembly-1.1.2.xsd">
 	<id>full</id>
 	<formats>
 		<format>jar</format>
diff --git a/spring-boot-tools/spring-boot-loader/src/it/executable-props/src/main/assembly/jar-with-dependencies.xml b/spring-boot-tools/spring-boot-loader/src/it/executable-props/src/main/assembly/jar-with-dependencies.xml
index 1120acb7e2..2dbf0f3a50 100644
--- a/spring-boot-tools/spring-boot-loader/src/it/executable-props/src/main/assembly/jar-with-dependencies.xml
+++ b/spring-boot-tools/spring-boot-loader/src/it/executable-props/src/main/assembly/jar-with-dependencies.xml
@@ -2,7 +2,7 @@
 <assembly
 	xmlns="http://maven.apache.org/plugins/maven-assembly-plugin/assembly/1.1.2"
 	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-	xsi:schemaLocation="http://maven.apache.org/plugins/maven-assembly-plugin/assembly/1.1.2 http://maven.apache.org/xsd/assembly-1.1.2.xsd">
+	xsi:schemaLocation="http://maven.apache.org/plugins/maven-assembly-plugin/assembly/1.1.2 https://maven.apache.org/xsd/assembly-1.1.2.xsd">
 	<id>full</id>
 	<formats>
 		<format>jar</format>
diff --git a/spring-boot-tools/spring-boot-loader/src/test/resources/root/META-INF/spring/application.xml b/spring-boot-tools/spring-boot-loader/src/test/resources/root/META-INF/spring/application.xml
index 704859f049..cf04aa4fbe 100644
--- a/spring-boot-tools/spring-boot-loader/src/test/resources/root/META-INF/spring/application.xml
+++ b/spring-boot-tools/spring-boot-loader/src/test/resources/root/META-INF/spring/application.xml
@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <beans xmlns="http://www.springframework.org/schema/beans"
 	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-	xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd">
+	xsi:schemaLocation="http://www.springframework.org/schema/beans https://www.springframework.org/schema/beans/spring-beans.xsd">
 
 </beans>
diff --git a/spring-boot-tools/spring-boot-maven-plugin/src/site/site.xml b/spring-boot-tools/spring-boot-maven-plugin/src/site/site.xml
index 0975cc901d..5014a3b439 100644
--- a/spring-boot-tools/spring-boot-maven-plugin/src/site/site.xml
+++ b/spring-boot-tools/spring-boot-maven-plugin/src/site/site.xml
@@ -1,5 +1,5 @@
 <project xmlns="http://maven.apache.org/DECORATION/1.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-		 xsi:schemaLocation="http://maven.apache.org/DECORATION/1.0.0 http://maven.apache.org/xsd/decoration-1.0.0.xsd">
+		 xsi:schemaLocation="http://maven.apache.org/DECORATION/1.0.0 https://maven.apache.org/xsd/decoration-1.0.0.xsd">
 	<body>
 		<menu name="Overview">
 			<item name="Introduction" href="index.html"/>
diff --git a/spring-boot/src/main/resources/org/springframework/boot/context/embedded/tomcat/empty-web.xml b/spring-boot/src/main/resources/org/springframework/boot/context/embedded/tomcat/empty-web.xml
index 14c04a5957..4ec3f71a4b 100644
--- a/spring-boot/src/main/resources/org/springframework/boot/context/embedded/tomcat/empty-web.xml
+++ b/spring-boot/src/main/resources/org/springframework/boot/context/embedded/tomcat/empty-web.xml
@@ -2,5 +2,5 @@
 <web-app version="3.0" xmlns="http://java.sun.com/xml/ns/javaee"
 	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 	xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
-	http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd">
+	https://java.sun.com/xml/ns/javaee/web-app_3_0.xsd">
 </web-app>
diff --git a/spring-boot/src/test/resources/org/springframework/boot/context/embedded/exampleEmbeddedWebApplicationConfiguration.xml b/spring-boot/src/test/resources/org/springframework/boot/context/embedded/exampleEmbeddedWebApplicationConfiguration.xml
index a03e06c9cf..bce6cd4ba2 100644
--- a/spring-boot/src/test/resources/org/springframework/boot/context/embedded/exampleEmbeddedWebApplicationConfiguration.xml
+++ b/spring-boot/src/test/resources/org/springframework/boot/context/embedded/exampleEmbeddedWebApplicationConfiguration.xml
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <beans xmlns="http://www.springframework.org/schema/beans"
 	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-	xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd">
+	xsi:schemaLocation="http://www.springframework.org/schema/beans https://www.springframework.org/schema/beans/spring-beans.xsd">
 
 	<bean name="servletContainerFactory"
 		class="org.springframework.boot.context.embedded.MockEmbeddedServletContainerFactory" />
diff --git a/spring-boot/src/test/resources/org/springframework/boot/context/properties/testProperties.xml b/spring-boot/src/test/resources/org/springframework/boot/context/properties/testProperties.xml
index bb8c2eb2de..e2c696175f 100644
--- a/spring-boot/src/test/resources/org/springframework/boot/context/properties/testProperties.xml
+++ b/spring-boot/src/test/resources/org/springframework/boot/context/properties/testProperties.xml
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <beans xmlns="http://www.springframework.org/schema/beans"
 	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-	xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd">
+	xsi:schemaLocation="http://www.springframework.org/schema/beans https://www.springframework.org/schema/beans/spring-beans.xsd">
 
 	<bean
 		id="org.springframework.boot.context.properties.EnableConfigurationPropertiesTests$TestProperties"
diff --git a/spring-boot/src/test/resources/org/springframework/boot/sample-beans.xml b/spring-boot/src/test/resources/org/springframework/boot/sample-beans.xml
index f0fb6ce513..f66853848f 100644
--- a/spring-boot/src/test/resources/org/springframework/boot/sample-beans.xml
+++ b/spring-boot/src/test/resources/org/springframework/boot/sample-beans.xml
@@ -2,8 +2,8 @@
 <beans xmlns="http://www.springframework.org/schema/beans"
 	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 	xmlns:context="http://www.springframework.org/schema/context"
-	xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
-				http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd">
+	xsi:schemaLocation="http://www.springframework.org/schema/beans https://www.springframework.org/schema/beans/spring-beans.xsd
+				http://www.springframework.org/schema/context https://www.springframework.org/schema/context/spring-context.xsd">
 
 	<bean id="myXmlComponent" class="org.springframework.boot.sampleconfig.MyComponent"/>
 </beans>