Raise the minimum supported version of Java to 17

Closes gh-749

Author: wilkinsona

build.gradle

@@ -39,8 +39,8 @@ subprojects { subproject ->
 		subproject.apply plugin: "io.spring.javaformat"
 		subproject.apply plugin: "checkstyle"
 
-		sourceCompatibility = 1.8
-		targetCompatibility = 1.8
+		sourceCompatibility = 17
+		targetCompatibility = 17
 
 		configurations {
 			internal {

ci/images/ci-image/Dockerfile

@@ -2,7 +2,7 @@ FROM ubuntu:focal-20210401
 
 ADD setup.sh /setup.sh
 ADD get-jdk-url.sh /get-jdk-url.sh
-RUN ./setup.sh java8
+RUN ./setup.sh java17
 
 ENV JAVA_HOME /opt/openjdk
 ENV PATH $JAVA_HOME/bin:$PATH

ci/images/get-jdk-url.sh

@@ -2,8 +2,8 @@
 set -e
 
 case "$1" in
-	java8)
-		 echo "https://github.com/AdoptOpenJDK/openjdk8-binaries/releases/download/jdk8u292-b10/OpenJDK8U-jdk_x64_linux_hotspot_8u292b10.tar.gz"
+	java17)
+		 echo "https://github.com/adoptium/temurin17-binaries/releases/download/jdk-17%2B35/OpenJDK17-jdk_x64_linux_hotspot_17_35.tar.gz"
 	;;
   *)
 		echo $"Unknown java version"

docs/src/docs/asciidoc/getting-started.adoc

@@ -76,7 +76,7 @@ If you want to jump straight in, a number of sample applications are available:
 
 Spring REST Docs has the following minimum requirements:
 
-* Java 8
+* Java 17
 * Spring Framework 5 (5.0.2 or later)
 
 Additionally, the `spring-restdocs-restassured` module requires REST Assured 4 (4.4 or later).

samples/junit5/build.gradle

@@ -16,8 +16,8 @@ repositories {
 
 group = 'com.example'
 
-sourceCompatibility = 1.8
-targetCompatibility = 1.8
+sourceCompatibility = 17
+targetCompatibility = 17
 
 ext {
 	snippetsDir = file('build/generated-snippets')

samples/rest-assured/build.gradle

@@ -16,8 +16,8 @@ repositories {
 
 group = 'com.example'
 
-sourceCompatibility = 1.8
-targetCompatibility = 1.8
+sourceCompatibility = 17
+targetCompatibility = 17
 
 ext {
 	snippetsDir = file('build/generated-snippets')

samples/rest-notes-slate/build.gradle

@@ -15,8 +15,8 @@ repositories {
 
 group = 'com.example'
 
-sourceCompatibility = 1.8
-targetCompatibility = 1.8
+sourceCompatibility = 17
+targetCompatibility = 17
 
 ext {
 	snippetsDir = file('build/generated-snippets')

samples/rest-notes-spring-data-rest/pom.xml

@@ -17,7 +17,7 @@
 
 	<properties>
 		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
-		<java.version>1.8</java.version>
+		<java.version>17</java.version>
 		<spring-restdocs.version>3.0.0-SNAPSHOT</spring-restdocs.version>
 	</properties>
 

samples/rest-notes-spring-hateoas/build.gradle

@@ -16,8 +16,8 @@ repositories {
 
 group = 'com.example'
 
-sourceCompatibility = 1.8
-targetCompatibility = 1.8
+sourceCompatibility = 17
+targetCompatibility = 17
 
 ext {
 	snippetsDir = file('build/generated-snippets')

samples/testng/build.gradle

@@ -16,8 +16,8 @@ repositories {
 
 group = 'com.example'
 
-sourceCompatibility = 1.8
-targetCompatibility = 1.8
+sourceCompatibility = 17
+targetCompatibility = 17
 
 ext {
 	snippetsDir = file('build/generated-snippets')

samples/web-test-client/build.gradle

@@ -14,8 +14,8 @@ repositories {
 
 group = 'com.example'
 
-sourceCompatibility = 1.8
-targetCompatibility = 1.8
+sourceCompatibility = 17
+targetCompatibility = 17
 
 ext {
 	snippetsDir = file('build/generated-snippets')

spring-restdocs-core/src/main/java/org/springframework/restdocs/operation/OperationResponseFactory.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2014-2019 the original author or authors.
+ * Copyright 2014-2021 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.
@@ -41,6 +41,15 @@ public OperationResponse create(HttpStatus status, HttpHeaders headers, byte[] c
 		return this.create(status.value(), headers, content);
 	}
 
+	/**
+	 * Creates a new {@link OperationResponse}. If the response has any content, the given
+	 * {@code headers} will be augmented to ensure that they include a
+	 * {@code Content-Length} header.
+	 * @param status the status of the response
+	 * @param headers the request's headers
+	 * @param content the content of the request
+	 * @return the {@code OperationResponse}
+	 */
 	public OperationResponse create(int status, HttpHeaders headers, byte[] content) {
 		return new StandardOperationResponse(status, augmentHeaders(headers, content), content);
 	}

spring-restdocs-webtestclient/src/main/java/org/springframework/restdocs/webtestclient/WebTestClientRequestConverter.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2014-2020 the original author or authors.
+ * Copyright 2014-2021 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.
@@ -110,7 +110,8 @@ private HttpMessageReader<Part> findPartHttpMessageReader() {
 		if (ClassUtils.isPresent(DEFAULT_PART_HTTP_MESSAGE_READER, getClass().getClassLoader())) {
 			try {
 				return (HttpMessageReader<Part>) Class
-						.forName(DEFAULT_PART_HTTP_MESSAGE_READER, true, getClass().getClassLoader()).newInstance();
+						.forName(DEFAULT_PART_HTTP_MESSAGE_READER, true, getClass().getClassLoader())
+						.getDeclaredConstructor().newInstance();
 			}
 			catch (Exception ex) {
 				// Continue