Upgrade non-specific guides to Java 8

README.adoc

@@ -19,6 +19,7 @@ You'll build a service that imports data from a CSV spreadsheet, transforms it w
 
 == What you'll need
 
+:java_version: 1.8
 include::https://raw.githubusercontent.com/spring-guides/getting-started-macros/master/prereq_editor_jdk_buildtools.adoc[]
 
 include::https://raw.githubusercontent.com/spring-guides/getting-started-macros/master/how_to_complete_this_guide.adoc[]

complete/build.gradle

@@ -21,6 +21,9 @@ repositories {
     mavenCentral()
 }
 
+sourceCompatibility = 1.8
+targetCompatibility = 1.8
+
 dependencies {
     compile("org.springframework.boot:spring-boot-starter-batch")
     compile("org.hsqldb:hsqldb")

complete/pom.xml

@@ -13,6 +13,10 @@
         <version>1.2.4.RELEASE</version>
     </parent>
     
+    <properties>
+        <java.version>1.8</java.version>
+    </properties>
+
     <dependencies>
         <dependency>
             <groupId>org.springframework.boot</groupId>

initial/build.gradle

@@ -21,6 +21,9 @@ repositories {
     mavenCentral()
 }
 
+sourceCompatibility = 1.8
+targetCompatibility = 1.8
+
 dependencies {
     compile("org.springframework.boot:spring-boot-starter-batch")
     compile("org.hsqldb:hsqldb")

initial/pom.xml

@@ -13,6 +13,10 @@
         <version>1.2.4.RELEASE</version>
     </parent>
     
+    <properties>
+        <java.version>1.8</java.version>
+    </properties>
+
     <dependencies>
         <dependency>
             <groupId>org.springframework.boot</groupId>